fix warnings about null-able

ExternalConnectors/CPS/PasswordstateInterface.cs

@@ -257,15 +257,9 @@ public class PasswordstateInterface
 
         return ""+textWriter.ToString();
     }
-    private class PasswordFinder : IPasswordFinder
+    private class PasswordFinder(string password) : IPasswordFinder
     {
-        private string password;
-
-        public PasswordFinder(string password)
-        {
-            this.password = password;
-        }
-
+        private string password = password;
 
         public char[] GetPassword()
         {

ExternalConnectors/DSS/SecretServerAuthentication.cs

@@ -58,10 +58,7 @@ namespace SecretServerAuthentication.DSS
         /// <param name="refresh_token">The refresh token.  Required when refreshing a token.</param>
         /// <returns>Successful retrieval of an access token</returns>
         /// <exception cref="ApiException">A server side error occurred.</exception>
-        public System.Threading.Tasks.Task<TokenResponse> AuthorizeAsync(Grant_type grant_type, string username, string password, string refresh_token, string OTP)
-        {
-            return AuthorizeAsync(grant_type, username, password, refresh_token, System.Threading.CancellationToken.None, OTP);
-        }
+        public System.Threading.Tasks.Task<TokenResponse> AuthorizeAsync(Grant_type grant_type, string username, string password, string refresh_token, string OTP) => AuthorizeAsync(grant_type, username, password, refresh_token, System.Threading.CancellationToken.None, OTP);
 
         /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
         /// <summary>Retrieve or Refresh Access Token</summary>
@@ -355,10 +352,7 @@ namespace SecretServerAuthentication.DSS
             Headers = headers;
         }
 
-        public override string ToString()
-        {
-            return string.Format("HTTP Response: \n\n{0}\n\n{1}", Response, base.ToString());
-        }
+        public override string ToString() => string.Format("HTTP Response: \n\n{0}\n\n{1}", Response, base.ToString());
     }
 
     [System.CodeDom.Compiler.GeneratedCode("NSwag", "13.14.8.0 (NJsonSchema v10.5.2.0 (Newtonsoft.Json v11.0.0.0))")]

ExternalConnectors/DSS/SecretServerInterface.cs

@@ -223,15 +223,9 @@ public class SecretServerInterface
 
         return ""+textWriter.ToString();
     }
-    private class PasswordFinder : IPasswordFinder
+    private class PasswordFinder(string password) : IPasswordFinder
     {
-        private string password;
-
-        public PasswordFinder(string password)
-        {
-            this.password = password;
-        }
-
+        private string password = password;
 
         public char[] GetPassword()
         {

ObjectListView/CellEditing/CellEditors.cs

@@ -46,18 +46,14 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// These items allow combo boxes to remember a value and its description.
     /// </summary>
-    public class ComboBoxItem
+    /// <remarks>
+    /// 
+    /// </remarks>
+    /// <param name="key"></param>
+    /// <param name="description"></param>
+    public class ComboBoxItem(Object key, String description)
     {
-        /// <summary>
-        /// 
-        /// </summary>
-        /// <param name="key"></param>
-        /// <param name="description"></param>
-        public ComboBoxItem(Object key, String description) {
-            this.key = key;
-            this.description = description;
-        }
-        private readonly String description;
+        private readonly String description = description;
 
         /// <summary>
         /// 
@@ -65,7 +61,7 @@ namespace BrightIdeasSoftware
         public Object Key {
             get { return key; }
         }
-        private readonly Object key;
+        private readonly Object key = key;
 
         /// <summary>
         /// Returns a string that represents the current object.

ObjectListView/FastObjectListView.cs

@@ -158,15 +158,12 @@ namespace BrightIdeasSoftware
     /// This class isn't intended to be used directly, but it is left as a public
     /// class just in case someone wants to subclass it.
     /// </remarks>
-    public class FastObjectListDataSource : AbstractVirtualListDataSource
+    /// <remarks>
+    /// Create a FastObjectListDataSource
+    /// </remarks>
+    /// <param name="listView"></param>
+    public class FastObjectListDataSource(FastObjectListView listView) : AbstractVirtualListDataSource(listView)
     {
-        /// <summary>
-        /// Create a FastObjectListDataSource
-        /// </summary>
-        /// <param name="listView"></param>
-        public FastObjectListDataSource(FastObjectListView listView)
-            : base(listView) {
-        }
 
         #region IVirtualListDataSource Members
 

ObjectListView/Filtering/Filters.cs

@@ -185,15 +185,11 @@ namespace BrightIdeasSoftware
     /// A model object must satisfy all filters to be included.
     /// If there are no filters, all model objects are included
     /// </summary>
-    public class CompositeAllFilter : CompositeFilter {
-
-        /// <summary>
-        /// Create a filter
-        /// </summary>
-        /// <param name="filters"></param>
-        public CompositeAllFilter(List<IModelFilter> filters)
-            : base(filters) {
-        }
+    /// <remarks>
+    /// Create a filter
+    /// </remarks>
+    /// <param name="filters"></param>
+    public class CompositeAllFilter(List<IModelFilter> filters) : CompositeFilter(filters) {
 
         /// <summary>
         /// Decide whether or not the given model should be included by the filter
@@ -215,15 +211,11 @@ namespace BrightIdeasSoftware
     /// A model object must only satisfy one of the filters to be included.
     /// If there are no filters, all model objects are included
     /// </summary>
-    public class CompositeAnyFilter : CompositeFilter {
-
-        /// <summary>
-        /// Create a filter from the given filters
-        /// </summary>
-        /// <param name="filters"></param>
-        public CompositeAnyFilter(List<IModelFilter> filters)
-            : base(filters) {
-        }
+    /// <remarks>
+    /// Create a filter from the given filters
+    /// </remarks>
+    /// <param name="filters"></param>
+    public class CompositeAnyFilter(List<IModelFilter> filters) : CompositeFilter(filters) {
 
         /// <summary>
         /// Decide whether or not the given model should be included by the filter

ObjectListView/Implementation/Comparers.cs

@@ -50,7 +50,13 @@ namespace BrightIdeasSoftware
     /// <para>This is used by normal (non-virtual) ObjectListViews. Virtual lists use
     /// ModelObjectComparer</para>
     /// </remarks>
-    public class ColumnComparer : IComparer, IComparer<OLVListItem>
+    /// <remarks>
+    /// Create a ColumnComparer that will order the rows in a list view according
+    /// to the values in a given column
+    /// </remarks>
+    /// <param name="col">The column whose values will be compared</param>
+    /// <param name="order">The ordering for column values</param>
+    public class ColumnComparer(OLVColumn col, SortOrder order) : IComparer, IComparer<OLVListItem>
     {
         /// <summary>
         /// Gets or sets the method that will be used to compare two strings.
@@ -63,18 +69,6 @@ namespace BrightIdeasSoftware
         }
         private static StringCompareDelegate stringComparer;
 
-        /// <summary>
-        /// Create a ColumnComparer that will order the rows in a list view according
-        /// to the values in a given column
-        /// </summary>
-        /// <param name="col">The column whose values will be compared</param>
-        /// <param name="order">The ordering for column values</param>
-        public ColumnComparer(OLVColumn col, SortOrder order)
-        {
-            this.column = col;
-            this.sortOrder = order;
-        }
-
         /// <summary>
         /// Create a ColumnComparer that will order the rows in a list view according
         /// to the values in a given column, and by a secondary column if the primary
@@ -165,8 +159,8 @@ namespace BrightIdeasSoftware
                 return StringComparer(x, y);
         }
 
-        private OLVColumn column;
-        private SortOrder sortOrder;
+        private OLVColumn column = col;
+        private SortOrder sortOrder = order;
         private ColumnComparer secondComparer;
     }
 
@@ -175,15 +169,12 @@ namespace BrightIdeasSoftware
     /// This comparer sort list view groups. OLVGroups have a "SortValue" property,
     /// which is used if present. Otherwise, the titles of the groups will be compared.
     /// </summary>
-    public class OLVGroupComparer : IComparer<OLVGroup>
+    /// <remarks>
+    /// Create a group comparer
+    /// </remarks>
+    /// <param name="order">The ordering for column values</param>
+    public class OLVGroupComparer(SortOrder order) : IComparer<OLVGroup>
     {
-        /// <summary>
-        /// Create a group comparer
-        /// </summary>
-        /// <param name="order">The ordering for column values</param>
-        public OLVGroupComparer(SortOrder order) {
-            this.sortOrder = order;
-        }
 
         /// <summary>
         /// Compare the two groups. OLVGroups have a "SortValue" property,
@@ -207,7 +198,7 @@ namespace BrightIdeasSoftware
             return result;
         }
 
-        private SortOrder sortOrder;
+        private SortOrder sortOrder = order;
     }
 
     /// <summary>
@@ -217,7 +208,12 @@ namespace BrightIdeasSoftware
     /// <para>This is used by virtual ObjectListViews. Non-virtual lists use
     /// ColumnComparer</para>
     /// </remarks>
-    public class ModelObjectComparer : IComparer, IComparer<object>
+    /// <remarks>
+    /// Create a model object comparer
+    /// </remarks>
+    /// <param name="col"></param>
+    /// <param name="order"></param>
+    public class ModelObjectComparer(OLVColumn col, SortOrder order) : IComparer, IComparer<object>
     {
         /// <summary>
         /// Gets or sets the method that will be used to compare two strings.
@@ -230,17 +226,6 @@ namespace BrightIdeasSoftware
         }
         private static StringCompareDelegate stringComparer;
 
-        /// <summary>
-        /// Create a model object comparer
-        /// </summary>
-        /// <param name="col"></param>
-        /// <param name="order"></param>
-        public ModelObjectComparer(OLVColumn col, SortOrder order)
-        {
-            this.column = col;
-            this.sortOrder = order;
-        }
-
         /// <summary>
         /// Create a model object comparer with a secondary sorting column
         /// </summary>
@@ -318,8 +303,8 @@ namespace BrightIdeasSoftware
                 return StringComparer(x, y);
         }
 
-        private OLVColumn column;
-        private SortOrder sortOrder;
+        private OLVColumn column = col;
+        private SortOrder sortOrder = order;
         private ModelObjectComparer secondComparer;
 
         #region IComparer<object> Members

ObjectListView/Implementation/Events.cs

@@ -878,25 +878,16 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// Let the world know that a cell edit operation is beginning or ending
     /// </summary>
-    public class CellEditEventArgs : EventArgs
+    /// <remarks>
+    /// Create an event args
+    /// </remarks>
+    /// <param name="column"></param>
+    /// <param name="control"></param>
+    /// <param name="cellBounds"></param>
+    /// <param name="item"></param>
+    /// <param name="subItemIndex"></param>
+    public class CellEditEventArgs(OLVColumn column, Control control, Rectangle cellBounds, OLVListItem item, int subItemIndex) : EventArgs
     {
-        /// <summary>
-        /// Create an event args
-        /// </summary>
-        /// <param name="column"></param>
-        /// <param name="control"></param>
-        /// <param name="cellBounds"></param>
-        /// <param name="item"></param>
-        /// <param name="subItemIndex"></param>
-        public CellEditEventArgs(OLVColumn column, Control control, Rectangle cellBounds, OLVListItem item, int subItemIndex) {
-            this.Control = control;
-            this.column = column;
-            this.cellBounds = cellBounds;
-            this.listViewItem = item;
-            this.rowObject = item.RowObject;
-            this.subItemIndex = subItemIndex;
-            this.value = column.GetValue(item.RowObject);
-        }
 
         /// <summary>
         /// Change this to true to cancel the cell editing operation.
@@ -917,7 +908,7 @@ namespace BrightIdeasSoftware
         /// entered and commit that value to the model. Changing the control during the finishing
         /// event has no effect.
         /// </summary>
-        public Control Control;
+        public Control Control = control;
 
         /// <summary>
         /// The column of the cell that is going to be or has been edited.
@@ -925,7 +916,7 @@ namespace BrightIdeasSoftware
         public OLVColumn Column {
             get { return this.column; }
         }
-        private OLVColumn column;
+        private OLVColumn column = column;
 
         /// <summary>
         /// The model object of the row of the cell that is going to be or has been edited.
@@ -933,7 +924,7 @@ namespace BrightIdeasSoftware
         public Object RowObject {
             get { return this.rowObject; }
         }
-        private Object rowObject;
+        private Object rowObject = item.RowObject;
 
         /// <summary>
         /// The listview item of the cell that is going to be or has been edited.
@@ -941,7 +932,7 @@ namespace BrightIdeasSoftware
         public OLVListItem ListViewItem {
             get { return this.listViewItem; }
         }
-        private OLVListItem listViewItem;
+        private OLVListItem listViewItem = item;
 
         /// <summary>
         /// The data value of the cell as it stands in the control.
@@ -959,7 +950,7 @@ namespace BrightIdeasSoftware
         public int SubItemIndex {
             get { return this.subItemIndex; }
         }
-        private int subItemIndex;
+        private int subItemIndex = subItemIndex;
 
         /// <summary>
         /// The data value of the cell before the edit operation began.
@@ -967,7 +958,7 @@ namespace BrightIdeasSoftware
         public Object Value {
             get { return this.value; }
         }
-        private Object value;
+        private Object value = column.GetValue(item.RowObject);
 
         /// <summary>
         /// The bounds of the cell that is going to be or has been edited.
@@ -975,7 +966,7 @@ namespace BrightIdeasSoftware
         public Rectangle CellBounds {
             get { return this.cellBounds; }
         }
-        private Rectangle cellBounds;
+        private Rectangle cellBounds = cellBounds;
 
         /// <summary>
         /// Gets or sets whether the control used for editing should be auto matically disposed
@@ -1160,25 +1151,22 @@ namespace BrightIdeasSoftware
         }
         private SortOrder secondarySortOrder;
     }
-    
+
     /// <summary>
     /// This event is triggered when the contents of a list have changed
     /// and we want the world to have a chance to filter the list.
     /// </summary>
-    public class FilterEventArgs : EventArgs
+    /// <remarks>
+    /// Create a FilterEventArgs
+    /// </remarks>
+    /// <param name="objects"></param>
+    public class FilterEventArgs(IEnumerable objects) : EventArgs
     {
-        /// <summary>
-        /// Create a FilterEventArgs
-        /// </summary>
-        /// <param name="objects"></param>
-        public FilterEventArgs(IEnumerable objects) {
-            this.Objects = objects;
-        }
 
         /// <summary>
         /// Gets or sets what objects are being filtered
         /// </summary>
-        public IEnumerable Objects;
+        public IEnumerable Objects = objects;
 
         /// <summary>
         /// Gets or sets what objects survived the filtering
@@ -1267,17 +1255,13 @@ namespace BrightIdeasSoftware
     /// <remarks>
     /// When used with a virtual list, OldObjects will always be null.
     /// </remarks>
-    public class ItemsChangingEventArgs : CancellableEventArgs
+    /// <remarks>
+    /// Create ItemsChangingEventArgs
+    /// </remarks>
+    /// <param name="oldObjects"></param>
+    /// <param name="newObjects"></param>
+    public class ItemsChangingEventArgs(IEnumerable oldObjects, IEnumerable newObjects) : CancellableEventArgs
     {
-        /// <summary>
-        /// Create ItemsChangingEventArgs
-        /// </summary>
-        /// <param name="oldObjects"></param>
-        /// <param name="newObjects"></param>
-        public ItemsChangingEventArgs(IEnumerable oldObjects, IEnumerable newObjects) {
-            this.oldObjects = oldObjects;
-            this.NewObjects = newObjects;
-        }
 
         /// <summary>
         /// Gets the objects that were in the list before it change.
@@ -1286,47 +1270,40 @@ namespace BrightIdeasSoftware
         public IEnumerable OldObjects {
             get { return oldObjects; }
         }
-        private IEnumerable oldObjects;
+        private IEnumerable oldObjects = oldObjects;
 
         /// <summary>
         /// Gets or sets the objects that will be in the list after it changes.
         /// </summary>
-        public IEnumerable NewObjects;
+        public IEnumerable NewObjects = newObjects;
     }
 
     /// <summary>
     /// This event is triggered by RemoveObjects before any change has been made to the list.
     /// </summary>
-    public class ItemsRemovingEventArgs : CancellableEventArgs
+    /// <remarks>
+    /// Create an ItemsRemovingEventArgs
+    /// </remarks>
+    /// <param name="objectsToRemove"></param>
+    public class ItemsRemovingEventArgs(ICollection objectsToRemove) : CancellableEventArgs
     {
-        /// <summary>
-        /// Create an ItemsRemovingEventArgs
-        /// </summary>
-        /// <param name="objectsToRemove"></param>
-        public ItemsRemovingEventArgs(ICollection objectsToRemove) {
-            this.ObjectsToRemove = objectsToRemove;
-        }
 
         /// <summary>
         /// Gets or sets the objects that will be removed
         /// </summary>
-        public ICollection ObjectsToRemove;
+        public ICollection ObjectsToRemove = objectsToRemove;
     }
 
     /// <summary>
     /// Triggered after the user types into a list
     /// </summary>
-    public class AfterSearchingEventArgs : EventArgs
+    /// <remarks>
+    /// Create an AfterSearchingEventArgs
+    /// </remarks>
+    /// <param name="stringToFind"></param>
+    /// <param name="indexSelected"></param>
+    public class AfterSearchingEventArgs(string stringToFind, int indexSelected) : EventArgs
     {
-        /// <summary>
-        /// Create an AfterSearchingEventArgs
-        /// </summary>
-        /// <param name="stringToFind"></param>
-        /// <param name="indexSelected"></param>
-        public AfterSearchingEventArgs(string stringToFind, int indexSelected) {
-            this.stringToFind = stringToFind;
-            this.indexSelected = indexSelected;
-        }
 
         /// <summary>
         /// Gets the string that was actually searched for
@@ -1334,7 +1311,7 @@ namespace BrightIdeasSoftware
         public string StringToFind {
             get { return this.stringToFind; }
         }
-        private string stringToFind;
+        private string stringToFind = stringToFind;
 
         /// <summary>
         /// Gets or sets whether an the event handler already handled this event
@@ -1348,23 +1325,19 @@ namespace BrightIdeasSoftware
         public int IndexSelected {
             get { return this.indexSelected; }
         }
-        private int indexSelected;
+        private int indexSelected = indexSelected;
     }
 
     /// <summary>
     /// Triggered when the user types into a list
     /// </summary>
-    public class BeforeSearchingEventArgs : CancellableEventArgs
+    /// <remarks>
+    /// Create BeforeSearchingEventArgs
+    /// </remarks>
+    /// <param name="stringToFind"></param>
+    /// <param name="startSearchFrom"></param>
+    public class BeforeSearchingEventArgs(string stringToFind, int startSearchFrom) : CancellableEventArgs
     {
-        /// <summary>
-        /// Create BeforeSearchingEventArgs
-        /// </summary>
-        /// <param name="stringToFind"></param>
-        /// <param name="startSearchFrom"></param>
-        public BeforeSearchingEventArgs(string stringToFind, int startSearchFrom) {
-            this.StringToFind = stringToFind;
-            this.StartSearchFrom = startSearchFrom;
-        }
 
         /// <summary>
         /// Gets or sets the string that will be found by the search routine
@@ -1372,12 +1345,12 @@ namespace BrightIdeasSoftware
         /// <remarks>Modifying this value does not modify the memory of what the user has typed. 
         /// When the user next presses a character, the search string will revert to what 
         /// the user has actually typed.</remarks>
-        public string StringToFind;
+        public string StringToFind = stringToFind;
 
         /// <summary>
         /// Gets or sets the index of the first row that will be considered to matching.
         /// </summary>
-        public int StartSearchFrom;
+        public int StartSearchFrom = startSearchFrom;
     }
 
     /// <summary>
@@ -2035,27 +2008,20 @@ namespace BrightIdeasSoftware
             return string.Format("NewHotCellHitLocation: {0}, HotCellHitLocationEx: {1}, NewHotColumnIndex: {2}, NewHotRowIndex: {3}, HotGroup: {4}", this.newHotCellHitLocation, this.hotCellHitLocationEx, this.newHotColumnIndex, this.newHotRowIndex, this.hotGroup);
         }
     }
-    
+
     /// <summary>
     /// Let the world know that a checkbox on a subitem is changing
     /// </summary>
-    public class SubItemCheckingEventArgs : CancellableEventArgs
+    /// <remarks>
+    /// Create a new event block
+    /// </remarks>
+    /// <param name="column"></param>
+    /// <param name="item"></param>
+    /// <param name="subItemIndex"></param>
+    /// <param name="currentValue"></param>
+    /// <param name="newValue"></param>
+    public class SubItemCheckingEventArgs(OLVColumn column, OLVListItem item, int subItemIndex, CheckState currentValue, CheckState newValue) : CancellableEventArgs
     {
-        /// <summary>
-        /// Create a new event block
-        /// </summary>
-        /// <param name="column"></param>
-        /// <param name="item"></param>
-        /// <param name="subItemIndex"></param>
-        /// <param name="currentValue"></param>
-        /// <param name="newValue"></param>
-        public SubItemCheckingEventArgs(OLVColumn column, OLVListItem item, int subItemIndex, CheckState currentValue, CheckState newValue) {
-            this.column = column;
-            this.listViewItem = item;
-            this.subItemIndex = subItemIndex;
-            this.currentValue = currentValue;
-            this.newValue = newValue;
-        }
 
         /// <summary>
         /// The column of the cell that is having its checkbox changed.
@@ -2063,7 +2029,7 @@ namespace BrightIdeasSoftware
         public OLVColumn Column {
             get { return this.column; }
         }
-        private OLVColumn column;
+        private OLVColumn column = column;
 
         /// <summary>
         /// The model object of the row of the cell that is having its checkbox changed.
@@ -2078,7 +2044,7 @@ namespace BrightIdeasSoftware
         public OLVListItem ListViewItem {
             get { return this.listViewItem; }
         }
-        private OLVListItem listViewItem;
+        private OLVListItem listViewItem = item;
 
         /// <summary>
         /// The current check state of the cell.
@@ -2086,7 +2052,7 @@ namespace BrightIdeasSoftware
         public CheckState CurrentValue {
             get { return this.currentValue; }
         }
-        private CheckState currentValue;
+        private CheckState currentValue = currentValue;
 
         /// <summary>
         /// The proposed new check state of the cell.
@@ -2095,7 +2061,7 @@ namespace BrightIdeasSoftware
             get { return this.newValue; }
             set { this.newValue = value; }
         }
-        private CheckState newValue;
+        private CheckState newValue = newValue;
 
         /// <summary>
         /// The index of the cell that is going to be or has been edited.
@@ -2103,21 +2069,18 @@ namespace BrightIdeasSoftware
         public int SubItemIndex {
             get { return this.subItemIndex; }
         }
-        private int subItemIndex;
+        private int subItemIndex = subItemIndex;
     }
 
     /// <summary>
     /// This event argument block is used when groups are created for a list.
     /// </summary>
-    public class CreateGroupsEventArgs : EventArgs
+    /// <remarks>
+    /// Create a CreateGroupsEventArgs
+    /// </remarks>
+    /// <param name="parms"></param>
+    public class CreateGroupsEventArgs(GroupingParameters parms) : EventArgs
     {
-        /// <summary>
-        /// Create a CreateGroupsEventArgs
-        /// </summary>
-        /// <param name="parms"></param>
-        public CreateGroupsEventArgs(GroupingParameters parms) {
-            this.parameters = parms;
-        }
 
         /// <summary>
         /// Gets the settings that control the creation of groups
@@ -2125,7 +2088,7 @@ namespace BrightIdeasSoftware
         public GroupingParameters Parameters {
             get { return this.parameters; }
         }
-        private GroupingParameters parameters;
+        private GroupingParameters parameters = parms;
 
         /// <summary>
         /// Gets or sets the groups that should be used
@@ -2151,16 +2114,12 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// This event argument block is used when the text of a group task is clicked
     /// </summary>
-    public class GroupTaskClickedEventArgs : EventArgs
+    /// <remarks>
+    /// Create a GroupTaskClickedEventArgs
+    /// </remarks>
+    /// <param name="group"></param>
+    public class GroupTaskClickedEventArgs(OLVGroup group) : EventArgs
     {
-        /// <summary>
-        /// Create a GroupTaskClickedEventArgs
-        /// </summary>
-        /// <param name="group"></param>
-        public GroupTaskClickedEventArgs(OLVGroup group)
-        {
-            this.group = group;
-        }
 
         /// <summary>
         /// Gets which group was clicked
@@ -2169,7 +2128,7 @@ namespace BrightIdeasSoftware
         {
             get { return this.group; }
         }
-        private readonly OLVGroup group;
+        private readonly OLVGroup group = group;
     }
 
     /// <summary>
@@ -2207,18 +2166,13 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// This event argument block is used when the state of group has changed (collapsed, selected)
     /// </summary>
-    public class GroupStateChangedEventArgs : EventArgs {
-        /// <summary>
-        /// Create a GroupStateChangedEventArgs
-        /// </summary>
-        /// <param name="group"></param>
-        /// <param name="oldState"> </param>
-        /// <param name="newState"> </param>
-        public GroupStateChangedEventArgs(OLVGroup group, GroupState oldState, GroupState newState) {
-            this.group = group;
-            this.oldState = oldState;
-            this.newState = newState;
-        }
+    /// <remarks>
+    /// Create a GroupStateChangedEventArgs
+    /// </remarks>
+    /// <param name="group"></param>
+    /// <param name="oldState"> </param>
+    /// <param name="newState"> </param>
+    public class GroupStateChangedEventArgs(OLVGroup group, GroupState oldState, GroupState newState) : EventArgs {
 
         /// <summary>
         /// Gets whether the group was collapsed by this event
@@ -2291,7 +2245,7 @@ namespace BrightIdeasSoftware
             get { return this.group; }
         }
 
-        private readonly OLVGroup group;
+        private readonly OLVGroup group = group;
 
         /// <summary>
         /// Gets the previous state of the group
@@ -2300,7 +2254,7 @@ namespace BrightIdeasSoftware
             get { return this.oldState; }
         }
 
-        private readonly GroupState oldState;
+        private readonly GroupState oldState = oldState;
 
 
         /// <summary>
@@ -2310,7 +2264,7 @@ namespace BrightIdeasSoftware
             get { return this.newState; }
         }
 
-        private readonly GroupState newState;
+        private readonly GroupState newState = newState;
     }
 
     /// <summary>

ObjectListView/Implementation/Munger.cs

@@ -311,18 +311,14 @@ namespace BrightIdeasSoftware
     /// <remarks>
     /// Munger uses a chain of these resolve a dotted aspect name.
     /// </remarks>
-    public class SimpleMunger
+    /// <remarks>
+    /// Create a SimpleMunger
+    /// </remarks>
+    /// <param name="aspectName"></param>
+    public class SimpleMunger(String aspectName)
     {
-        #region Life and death
 
-        /// <summary>
-        /// Create a SimpleMunger
-        /// </summary>
-        /// <param name="aspectName"></param>
-        public SimpleMunger(String aspectName)
-        {
-            this.aspectName = aspectName;
-        }
+        #region Life and death
 
         #endregion
 
@@ -344,7 +340,7 @@ namespace BrightIdeasSoftware
         public string AspectName {
             get { return aspectName; }
         }
-        private readonly string aspectName;
+        private readonly string aspectName = aspectName;
 
         #endregion
 
@@ -494,19 +490,14 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// These exceptions are raised when a munger finds something it cannot process
     /// </summary>
-    public class MungerException : ApplicationException
+    /// <remarks>
+    /// Create a MungerException
+    /// </remarks>
+    /// <param name="munger"></param>
+    /// <param name="target"></param>
+    /// <param name="ex"></param>
+    public class MungerException(SimpleMunger munger, object target, Exception ex) : ApplicationException("Munger failed", ex)
     {
-        /// <summary>
-        /// Create a MungerException
-        /// </summary>
-        /// <param name="munger"></param>
-        /// <param name="target"></param>
-        /// <param name="ex"></param>
-        public MungerException(SimpleMunger munger, object target, Exception ex)
-            : base("Munger failed", ex) {
-            this.munger = munger;
-            this.target = target;
-        }
 
         /// <summary>
         /// Get the munger that raised the exception
@@ -514,7 +505,7 @@ namespace BrightIdeasSoftware
         public SimpleMunger Munger {
             get { return munger; }
         }
-        private readonly SimpleMunger munger;
+        private readonly SimpleMunger munger = munger;
 
         /// <summary>
         /// Gets the target that threw the exception
@@ -522,7 +513,7 @@ namespace BrightIdeasSoftware
         public object Target {
             get { return target; }
         }
-        private readonly object target;
+        private readonly object target = target;
     }
 
     /*

ObjectListView/Implementation/VirtualGroups.cs

@@ -309,12 +309,9 @@ namespace BrightIdeasSoftware
     /// A default implementation of the IOwnerDataCallback interface
     /// </summary>
     [Guid("6FC61F50-80E8-49b4-B200-3F38D3865ABD")]
-    internal class OwnerDataCallbackImpl : IOwnerDataCallback
+    internal class OwnerDataCallbackImpl(VirtualObjectListView olv) : IOwnerDataCallback
     {
-        public OwnerDataCallbackImpl(VirtualObjectListView olv) {
-            this.olv = olv;
-        }
-        VirtualObjectListView olv;
+        VirtualObjectListView olv = olv;
 
         #region IOwnerDataCallback Members
 

ObjectListView/Implementation/VirtualListDataSource.cs

@@ -145,20 +145,17 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// A do-nothing implementation of the VirtualListDataSource interface.
     /// </summary>
-    public class AbstractVirtualListDataSource : IVirtualListDataSource, IFilterableDataSource
+    /// <remarks>
+    /// Creates an AbstractVirtualListDataSource
+    /// </remarks>
+    /// <param name="listView"></param>
+    public class AbstractVirtualListDataSource(VirtualObjectListView listView) : IVirtualListDataSource, IFilterableDataSource
     {
-        /// <summary>
-        /// Creates an AbstractVirtualListDataSource
-        /// </summary>
-        /// <param name="listView"></param>
-        public AbstractVirtualListDataSource(VirtualObjectListView listView) {
-            this.listView = listView;
-        }
 
         /// <summary>
         /// The list view that this data source is giving information to.
         /// </summary>
-        protected VirtualObjectListView listView;
+        protected VirtualObjectListView listView = listView;
 
         /// <summary>
         /// 
@@ -295,15 +292,12 @@ namespace BrightIdeasSoftware
     /// <summary>
     /// This class mimics the behavior of VirtualObjectListView v1.x.
     /// </summary>
-    public class VirtualListVersion1DataSource : AbstractVirtualListDataSource
+    /// <remarks>
+    /// Creates a VirtualListVersion1DataSource
+    /// </remarks>
+    /// <param name="listView"></param>
+    public class VirtualListVersion1DataSource(VirtualObjectListView listView) : AbstractVirtualListDataSource(listView)
     {
-        /// <summary>
-        /// Creates a VirtualListVersion1DataSource
-        /// </summary>
-        /// <param name="listView"></param>
-        public VirtualListVersion1DataSource(VirtualObjectListView listView)
-            : base(listView) {
-        }
 
         #region Public properties
 

ObjectListView/ObjectListView.DesignTime.cs

@@ -369,14 +369,8 @@ namespace BrightIdeasSoftware.Design
         /// only have to modify the returned collection of actions, but we have to implement
         /// the properties and commands that the returned actions use. </para>
         /// </remarks>
-        private class ListViewActionListAdapter : DesignerActionList
+        private class ListViewActionListAdapter(ObjectListViewDesigner designer, DesignerActionList wrappedList) : DesignerActionList(wrappedList.Component)
         {
-            public ListViewActionListAdapter(ObjectListViewDesigner designer, DesignerActionList wrappedList)
-                : base(wrappedList.Component) {
-                this.designer = designer;
-                this.wrappedList = wrappedList;
-            }
-
             public override DesignerActionItemCollection GetSortedActionItems() {
                 DesignerActionItemCollection items = wrappedList.GetSortedActionItems();
                 items.RemoveAt(2); // remove Edit Groups
@@ -425,21 +419,16 @@ namespace BrightIdeasSoftware.Design
                 set { SetValue(base.Component, "View", value); }
             }
 
-            ObjectListViewDesigner designer;
-            DesignerActionList wrappedList;
+            ObjectListViewDesigner designer = designer;
+            DesignerActionList wrappedList = wrappedList;
         }
 
         #endregion
 
         #region DesignerCommandSet
 
-        private class CDDesignerCommandSet : DesignerCommandSet
+        private class CDDesignerCommandSet(ComponentDesigner componentDesigner) : DesignerCommandSet
         {
-
-            public CDDesignerCommandSet(ComponentDesigner componentDesigner) {
-                this.componentDesigner = componentDesigner;
-            }
-
             public override ICollection GetCommands(string name) {
                 // Debug.WriteLine("CDDesignerCommandSet.GetCommands:" + name);
                 if (componentDesigner != null) {
@@ -453,7 +442,7 @@ namespace BrightIdeasSoftware.Design
                 return base.GetCommands(name);
             }
 
-            private readonly ComponentDesigner componentDesigner;
+            private readonly ComponentDesigner componentDesigner = componentDesigner;
         }
 
         #endregion
@@ -463,15 +452,12 @@ namespace BrightIdeasSoftware.Design
     /// This class works in conjunction with the OLVColumns property to allow OLVColumns
     /// to be added to the ObjectListView.
     /// </summary>
-    public class OLVColumnCollectionEditor : System.ComponentModel.Design.CollectionEditor
+    /// <remarks>
+    /// Create a OLVColumnCollectionEditor
+    /// </remarks>
+    /// <param name="t"></param>
+    public class OLVColumnCollectionEditor(Type t) : System.ComponentModel.Design.CollectionEditor(t)
     {
-        /// <summary>
-        /// Create a OLVColumnCollectionEditor
-        /// </summary>
-        /// <param name="t"></param>
-        public OLVColumnCollectionEditor(Type t)
-            : base(t) {
-        }
 
         /// <summary>
         /// What type of object does this editor create?

ObjectListView/ObjectListView.cs

@@ -588,6 +588,7 @@ using System.Runtime.Versioning;
 using System.Threading;
 using System.Windows.Forms;
 using System.Windows.Forms.VisualStyles;
+using System.Text.Json;
 
 using MethodInvoker = System.Windows.Forms.MethodInvoker;
 
@@ -5869,9 +5870,18 @@ namespace BrightIdeasSoftware
             // Now that we have stored our state, convert it to a byte array
             using (MemoryStream ms = new MemoryStream())
             {
-                BinaryFormatter serializer = new BinaryFormatter();
-                serializer.AssemblyFormat = FormatterAssemblyStyle.Simple;
-                serializer.Serialize(ms, olvState);
+                //BinaryFormatter serializer = new BinaryFormatter();
+                //serializer.AssemblyFormat = FormatterAssemblyStyle.Simple;
+                //serializer.Serialize(ms, olvState);
+                //return ms.ToArray();
+
+                // Use System.Text.Json for serialization instead of BinaryFormatter
+                var options = new JsonSerializerOptions
+                {
+                    WriteIndented = false
+                };
+                byte[] serializedData = JsonSerializer.SerializeToUtf8Bytes(olvState, options);
+                ms.Write(serializedData, 0, serializedData.Length);
                 return ms.ToArray();
             }
         }
@@ -5886,6 +5896,7 @@ namespace BrightIdeasSoftware
         {
             using (MemoryStream ms = new MemoryStream(state))
             {
+                /*
                 BinaryFormatter deserializer = new BinaryFormatter();
                 ObjectListViewState olvState;
                 try
@@ -5925,6 +5936,45 @@ namespace BrightIdeasSoftware
                     this.RebuildColumns();
                 else
                     this.View = olvState.CurrentView;
+                */
+                ObjectListViewState olvState;
+                try
+                {
+                    olvState = JsonSerializer.Deserialize<ObjectListViewState>(ms.ToArray());
+                }
+                catch (JsonException)
+                {
+                    return false;
+                }
+                // The number of columns has changed. We have no way to match old
+                // columns to the new ones, so we just give up.
+                if (olvState == null || olvState.NumberOfColumns != this.AllColumns.Count)
+                    return false;
+                if (olvState.SortColumn == -1)
+                {
+                    this.PrimarySortColumn = null;
+                    this.PrimarySortOrder = SortOrder.None;
+                }
+                else
+                {
+                    this.PrimarySortColumn = this.AllColumns[olvState.SortColumn];
+                    this.PrimarySortOrder = olvState.LastSortOrder;
+                }
+                for (int i = 0; i < olvState.NumberOfColumns; i++)
+                {
+                    OLVColumn column = this.AllColumns[i];
+                    column.Width = (int)olvState.ColumnWidths[i];
+                    column.IsVisible = (bool)olvState.ColumnIsVisible[i];
+                    column.LastDisplayIndex = (int)olvState.ColumnDisplayIndicies[i];
+                }
+                // ReSharper disable RedundantCheckBeforeAssignment
+                if (olvState.IsShowingGroups != this.ShowGroups)
+                    // ReSharper restore RedundantCheckBeforeAssignment
+                    this.ShowGroups = olvState.IsShowingGroups;
+                if (this.View == olvState.CurrentView)
+                    this.RebuildColumns();
+                else
+                    this.View = olvState.CurrentView;
             }
 
             return true;

ObjectListView/Rendering/Renderers.cs

@@ -231,15 +231,12 @@ namespace BrightIdeasSoftware {
     /// This class provides compatibility for v1 RendererDelegates
     /// </summary>
     [ToolboxItem(false)]
-    internal class Version1Renderer : AbstractRenderer {
-        public Version1Renderer(RenderDelegate renderDelegate) {
-            this.RenderDelegate = renderDelegate;
-        }
+    internal class Version1Renderer(RenderDelegate renderDelegate) : AbstractRenderer {
 
         /// <summary>
         /// The renderer delegate that this renderer wraps
         /// </summary>
-        public RenderDelegate RenderDelegate;
+        public RenderDelegate RenderDelegate = renderDelegate;
 
         #region IRenderer Members
 

ObjectListView/SubControls/HeaderControl.cs

@@ -51,17 +51,20 @@
  * If you wish to use this code in a closed source application, please contact phillip.piper@gmail.com.
  */
 
+using BrightIdeasSoftware.Properties;
+
 using System;
 using System.Drawing;
-using System.Windows.Forms;
-using System.Runtime.InteropServices;
-using System.Windows.Forms.VisualStyles;
 using System.Drawing.Drawing2D;
-using BrightIdeasSoftware.Properties;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
 using System.Security.Permissions;
+using System.Windows.Forms;
+using System.Windows.Forms.VisualStyles;
 
 namespace BrightIdeasSoftware
 {
+    [SupportedOSPlatform("windows")]
     /// <summary>
     /// Class used to capture window messages for the header of the list view
     /// control.

ObjectListView/SubControls/ToolTipControl.cs

@@ -40,11 +40,13 @@ using System.Collections;
 using System.ComponentModel;
 using System.Drawing;
 using System.Runtime.InteropServices;
-using System.Windows.Forms;
+using System.Runtime.Versioning;
 using System.Security.Permissions;
+using System.Windows.Forms;
 
 namespace BrightIdeasSoftware
 {
+    [SupportedOSPlatform("windows")]
     /// <summary>
     /// A limited wrapper around a Windows tooltip window.
     /// </summary>

ObjectListView/TreeListView.cs

@@ -2180,15 +2180,12 @@ namespace BrightIdeasSoftware
         /// <summary>
         /// This class sorts branches according to how their respective model objects are sorted
         /// </summary>
-        public class BranchComparer : IComparer<Branch>
+        /// <remarks>
+        /// Create a BranchComparer
+        /// </remarks>
+        /// <param name="actualComparer"></param>
+        public class BranchComparer(IComparer actualComparer) : IComparer<Branch>
         {
-            /// <summary>
-            /// Create a BranchComparer
-            /// </summary>
-            /// <param name="actualComparer"></param>
-            public BranchComparer(IComparer actualComparer) {
-                this.actualComparer = actualComparer;
-            }
 
             /// <summary>
             /// Order the two branches
@@ -2200,7 +2197,7 @@ namespace BrightIdeasSoftware
                 return this.actualComparer.Compare(x.Model, y.Model);
             }
 
-            private readonly IComparer actualComparer;
+            private readonly IComparer actualComparer = actualComparer;
         }
 
     }

ObjectListView/Utilities/ColumnSelectionForm.cs

@@ -233,13 +233,9 @@ namespace BrightIdeasSoftware
         /// A Comparer that will sort a list of columns so that visible ones come before hidden ones,
         /// and that are ordered by their display order.
         /// </summary>
-        private class SortByDisplayOrder : IComparer<OLVColumn>
+        private class SortByDisplayOrder(ColumnSelectionForm form) : IComparer<OLVColumn>
         {
-            public SortByDisplayOrder(ColumnSelectionForm form)
-            {
-                this.Form = form;
-            }
-            private ColumnSelectionForm Form;
+            private ColumnSelectionForm Form = form;
 
             #region IComparer<OLVColumn> Members
 

ObjectListView/Utilities/TypedObjectListView.cs

@@ -72,15 +72,12 @@ namespace BrightIdeasSoftware
     /// }
     /// </code>
     /// </example>
-    public class TypedObjectListView<T> where T : class
+    /// <remarks>
+    /// Create a typed wrapper around the given list.
+    /// </remarks>
+    /// <param name="olv">The listview to be wrapped</param>
+    public class TypedObjectListView<T>(ObjectListView olv) where T : class
     {
-        /// <summary>
-        /// Create a typed wrapper around the given list.
-        /// </summary>
-        /// <param name="olv">The listview to be wrapped</param>
-        public TypedObjectListView(ObjectListView olv) {
-            this.olv = olv;
-        }
 
         //--------------------------------------------------------------------------------------
         // Properties
@@ -115,7 +112,7 @@ namespace BrightIdeasSoftware
             get { return olv; }
             set { olv = value; }
         }
-        private ObjectListView olv;
+        private ObjectListView olv = olv;
 
         /// <summary>
         /// Get or set the list of all model objects
@@ -325,16 +322,13 @@ namespace BrightIdeasSoftware
     /// A type-safe wrapper around an OLVColumn
     /// </summary>
     /// <typeparam name="T"></typeparam>
-    public class TypedColumn<T> where T : class
+    /// <remarks>
+    /// Creates a TypedColumn
+    /// </remarks>
+    /// <param name="column"></param>
+    public class TypedColumn<T>(OLVColumn column) where T : class
     {
-        /// <summary>
-        /// Creates a TypedColumn
-        /// </summary>
-        /// <param name="column"></param>
-        public TypedColumn(OLVColumn column) {
-            this.column = column;
-        }
-        private OLVColumn column;
+        private OLVColumn column = column;
 
         /// <summary>
         /// 

mRemoteNG/App/Initialization/StartupDataLogger.cs

@@ -9,14 +9,9 @@ using mRemoteNG.Resources.Language;
 namespace mRemoteNG.App.Initialization
 {
     [SupportedOSPlatform("windows")]
-    public class StartupDataLogger
+    public class StartupDataLogger(MessageCollector messageCollector)
     {
-        private readonly MessageCollector _messageCollector;
-
-        public StartupDataLogger(MessageCollector messageCollector)
-        {
-            _messageCollector = messageCollector ?? throw new ArgumentNullException(nameof(messageCollector));
-        }
+        private readonly MessageCollector _messageCollector = messageCollector ?? throw new ArgumentNullException(nameof(messageCollector));
 
         public void LogStartupData()
         {

mRemoteNG/Config/Connections/SqlConnectionsLoader.cs

@@ -19,22 +19,16 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Connections
 {
     [SupportedOSPlatform("windows")]
-    public class SqlConnectionsLoader : IConnectionsLoader
+    public class SqlConnectionsLoader(
+        IDeserializer<string, IEnumerable<LocalConnectionPropertiesModel>> localConnectionPropertiesDeserializer,
+        IDataProvider<string> dataProvider) : IConnectionsLoader
     {
-        private readonly IDeserializer<string, IEnumerable<LocalConnectionPropertiesModel>> _localConnectionPropertiesDeserializer;
+        private readonly IDeserializer<string, IEnumerable<LocalConnectionPropertiesModel>> _localConnectionPropertiesDeserializer = localConnectionPropertiesDeserializer.ThrowIfNull(nameof(localConnectionPropertiesDeserializer));
 
-        private readonly IDataProvider<string> _dataProvider;
+        private readonly IDataProvider<string> _dataProvider = dataProvider.ThrowIfNull(nameof(dataProvider));
 
         private Func<Optional<SecureString>> AuthenticationRequestor { get; set; } = () => MiscTools.PasswordDialog("", false);
 
-        public SqlConnectionsLoader(
-            IDeserializer<string, IEnumerable<LocalConnectionPropertiesModel>> localConnectionPropertiesDeserializer,
-            IDataProvider<string> dataProvider)
-        {
-            _localConnectionPropertiesDeserializer = localConnectionPropertiesDeserializer.ThrowIfNull(nameof(localConnectionPropertiesDeserializer));
-            _dataProvider = dataProvider.ThrowIfNull(nameof(dataProvider));
-        }
-
         public ConnectionTreeModel Load()
         {
             IDatabaseConnector connector = DatabaseConnectorFactory.DatabaseConnectorFromSettings();

mRemoteNG/Config/Connections/SqlConnectionsSaver.cs

@@ -23,18 +23,11 @@ using mRemoteNG.Config.Serializers.ConnectionSerializers.Sql;
 namespace mRemoteNG.Config.Connections
 {
     [SupportedOSPlatform("windows")]
-    public class SqlConnectionsSaver : ISaver<ConnectionTreeModel>
+    public class SqlConnectionsSaver(SaveFilter saveFilter, ISerializer<IEnumerable<LocalConnectionPropertiesModel>, string> localPropertieSerializer, IDataProvider<string> localPropertiesDataProvider) : ISaver<ConnectionTreeModel>
     {
-        private readonly SaveFilter _saveFilter;
-        private readonly ISerializer<IEnumerable<LocalConnectionPropertiesModel>, string> _localPropertiesSerializer;
-        private readonly IDataProvider<string> _dataProvider;
-
-        public SqlConnectionsSaver(SaveFilter saveFilter, ISerializer<IEnumerable<LocalConnectionPropertiesModel>, string> localPropertieSerializer, IDataProvider<string> localPropertiesDataProvider)
-        {
-            _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
-            _localPropertiesSerializer = localPropertieSerializer.ThrowIfNull(nameof(localPropertieSerializer));
-            _dataProvider = localPropertiesDataProvider.ThrowIfNull(nameof(localPropertiesDataProvider));
-        }
+        private readonly SaveFilter _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
+        private readonly ISerializer<IEnumerable<LocalConnectionPropertiesModel>, string> _localPropertiesSerializer = localPropertieSerializer.ThrowIfNull(nameof(localPropertieSerializer));
+        private readonly IDataProvider<string> _dataProvider = localPropertiesDataProvider.ThrowIfNull(nameof(localPropertiesDataProvider));
 
         public void Save(ConnectionTreeModel connectionTreeModel, string propertyNameTrigger = "")
         {

mRemoteNG/Config/DataProviders/FileDataProvider.cs

@@ -6,15 +6,10 @@ using mRemoteNG.App;
 namespace mRemoteNG.Config.DataProviders
 {
     [SupportedOSPlatform("windows")]
-    public class FileDataProvider : IDataProvider<string>
+    public class FileDataProvider(string filePath) : IDataProvider<string>
     {
         [SupportedOSPlatform("windows")]
-        public string FilePath { get; set; }
-
-        public FileDataProvider(string filePath)
-        {
-            FilePath = filePath;
-        }
+        public string FilePath { get; set; } = filePath;
 
         public virtual string Load()
         {

mRemoteNG/Config/DataProviders/FileDataProviderWithRollingBackup.cs

@@ -3,14 +3,9 @@
 namespace mRemoteNG.Config.DataProviders
 {
     [SupportedOSPlatform("windows")]
-    public class FileDataProviderWithRollingBackup : FileDataProvider
+    public class FileDataProviderWithRollingBackup(string filePath) : FileDataProvider(filePath)
     {
-        private readonly FileBackupCreator _fileBackupCreator;
-
-        public FileDataProviderWithRollingBackup(string filePath) : base(filePath)
-        {
-            _fileBackupCreator = new FileBackupCreator();
-        }
+        private readonly FileBackupCreator _fileBackupCreator = new FileBackupCreator();
 
         public override void Save(string content)
         {

mRemoteNG/Config/DataProviders/InMemoryStringDataProvider.cs

@@ -1,13 +1,8 @@
 namespace mRemoteNG.Config.DataProviders
 {
-    public class InMemoryStringDataProvider : IDataProvider<string>
+    public class InMemoryStringDataProvider(string initialContents = "") : IDataProvider<string>
     {
-        private string _contents;
-
-        public InMemoryStringDataProvider(string initialContents = "")
-        {
-            _contents = initialContents;
-        }
+        private string _contents = initialContents;
 
         public string Load()
         {

mRemoteNG/Config/DataProviders/SqlDataProvider.cs

@@ -9,14 +9,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.DataProviders
 {
     [SupportedOSPlatform("windows")]
-    public class SqlDataProvider : IDataProvider<DataTable>
+    public class SqlDataProvider(IDatabaseConnector databaseConnector) : IDataProvider<DataTable>
     {
-        public IDatabaseConnector DatabaseConnector { get; }
-
-        public SqlDataProvider(IDatabaseConnector databaseConnector)
-        {
-            DatabaseConnector = databaseConnector;
-        }
+        public IDatabaseConnector DatabaseConnector { get; } = databaseConnector;
 
         public DataTable Load()
         {

mRemoteNG/Config/DatabaseConnectors/DatabaseConnectionTester.cs

@@ -17,21 +17,40 @@ namespace mRemoteNG.Config.DatabaseConnectors
 
     public class DatabaseConnectionTester
     {
-        //string connectionString = "Data Source=172.22.155.100,1433;Initial Catalog=Demo;User ID=sa;Password=London123";
-        
-        public static void TestConnection(string connectionString)
+        public async Task<ConnectionTestResult> TestConnectivity(string type, string server, string database, string username, string password)
         {
             try
             {
+                // Build the connection string based on the provided parameters
+                string connectionString = $"Data Source={server};Initial Catalog={database};User ID={username};Password={password}";
+
+                // Attempt to open a connection to the database
                 using (SqlConnection connection = new SqlConnection(connectionString))
                 {
-                    connection.Open();
-                    Console.WriteLine("Connection successful!");
+                    await connection.OpenAsync();
+                }
+
+                return ConnectionTestResult.ConnectionSucceded;
+            }
+            catch (SqlException ex)
+            {
+                // Handle specific SQL exceptions
+                switch (ex.Number)
+                {
+                    case 4060: // Invalid Database
+                        return ConnectionTestResult.UnknownDatabase;
+                    case 18456: // Login Failed
+                        return ConnectionTestResult.CredentialsRejected;
+                    case -1: // Server not accessible
+                        return ConnectionTestResult.ServerNotAccessible;
+                    default:
+                        return ConnectionTestResult.UnknownError;
                 }
             }
-            catch (Exception ex)
+            catch
             {
-                Console.WriteLine($"Connection failed: {ex.Message}");
+                // Handle any other exceptions
+                return ConnectionTestResult.UnknownError;
             }
         }
     }

mRemoteNG/Config/Import/PortScanImporter.cs

@@ -10,14 +10,9 @@ using mRemoteNG.Tools;
 namespace mRemoteNG.Config.Import
 {
     [SupportedOSPlatform("windows")]
-    public class PortScanImporter : IConnectionImporter<IEnumerable<ScanHost>>
+    public class PortScanImporter(ProtocolType targetProtocolType) : IConnectionImporter<IEnumerable<ScanHost>>
     {
-        private readonly ProtocolType _targetProtocolType;
-
-        public PortScanImporter(ProtocolType targetProtocolType)
-        {
-            _targetProtocolType = targetProtocolType;
-        }
+        private readonly ProtocolType _targetProtocolType = targetProtocolType;
 
         public void Import(IEnumerable<ScanHost> hosts, ContainerInfo destinationContainer)
         {

mRemoteNG/Config/Putty/PuttySessionChangedEventArgs.cs

@@ -4,13 +4,8 @@ using mRemoteNG.Connection;
 
 namespace mRemoteNG.Config.Putty
 {
-    public class PuttySessionChangedEventArgs : EventArgs
+    public class PuttySessionChangedEventArgs(PuttySessionInfo sessionChanged = null) : EventArgs
     {
-        public PuttySessionInfo Session { get; set; }
-
-        public PuttySessionChangedEventArgs(PuttySessionInfo sessionChanged = null)
-        {
-            Session = sessionChanged;
-        }
+        public PuttySessionInfo Session { get; set; } = sessionChanged;
     }
 }

mRemoteNG/Config/Putty/PuttySessionsManager.cs

@@ -135,17 +135,17 @@ namespace mRemoteNG.Config.Putty
         {
             public static string[] Names => Instance.GetSessionNames();
 
-            public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
+            public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext? context)
             {
                 return new StandardValuesCollection(Names);
             }
 
-            public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
+            public override bool GetStandardValuesExclusive(ITypeDescriptorContext? context)
             {
                 return true;
             }
 
-            public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
+            public override bool GetStandardValuesSupported(ITypeDescriptorContext? context)
             {
                 return true;
             }

mRemoteNG/Config/Serializers/ConnectionSerializers/Sql/DataTableDeserializer.cs

@@ -21,16 +21,10 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Sql
 {
     [SupportedOSPlatform("windows")]
-    public class DataTableDeserializer : IDeserializer<DataTable, ConnectionTreeModel>
+    public class DataTableDeserializer(ICryptographyProvider cryptographyProvider, SecureString decryptionKey) : IDeserializer<DataTable, ConnectionTreeModel>
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly SecureString _decryptionKey;
-
-        public DataTableDeserializer(ICryptographyProvider cryptographyProvider, SecureString decryptionKey)
-        {
-            _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
-            _decryptionKey = decryptionKey.ThrowIfNull(nameof(decryptionKey));
-        }
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
+        private readonly SecureString _decryptionKey = decryptionKey.ThrowIfNull(nameof(decryptionKey));
 
         public ConnectionTreeModel Deserialize(DataTable table)
         {

mRemoteNG/Config/Serializers/ConnectionSerializers/Sql/DataTableSerializer.cs

@@ -14,27 +14,20 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Sql
 {
     [SupportedOSPlatform("windows")]
-    public class DataTableSerializer : ISerializer<ConnectionInfo, DataTable>
+    public class DataTableSerializer(SaveFilter saveFilter, ICryptographyProvider cryptographyProvider, SecureString encryptionKey) : ISerializer<ConnectionInfo, DataTable>
     {
         private const int DELETE = 0;
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly SecureString _encryptionKey;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
+        private readonly SecureString _encryptionKey = encryptionKey.ThrowIfNull(nameof(encryptionKey));
         private DataTable _dataTable;
         private DataTable _sourceDataTable;
         private readonly Dictionary<string, int> _sourcePrimaryKeyDict = [];
         private const string TABLE_NAME = "tblCons";
-        private readonly SaveFilter _saveFilter;
+        private readonly SaveFilter _saveFilter = saveFilter.ThrowIfNull(nameof(saveFilter));
         private int _currentNodeIndex;
 
         public Version Version { get; } = new Version(3, 0);
 
-        public DataTableSerializer(SaveFilter saveFilter, ICryptographyProvider cryptographyProvider, SecureString encryptionKey)
-        {
-            _saveFilter = saveFilter.ThrowIfNull(nameof(saveFilter));
-            _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
-            _encryptionKey = encryptionKey.ThrowIfNull(nameof(encryptionKey));
-        }
-
         public void SetSourceDataTable(DataTable sourceDataTable)
         {
             _sourceDataTable = sourceDataTable;

mRemoteNG/Config/Serializers/ConnectionSerializers/Xml/XmlConnectionNodeSerializer27.cs

@@ -11,23 +11,16 @@ namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Xml
 {
     // ReSharper disable once InconsistentNaming
     [SupportedOSPlatform("windows")]
-    public class XmlConnectionNodeSerializer27 : ISerializer<ConnectionInfo, XElement>
+    public class XmlConnectionNodeSerializer27(ICryptographyProvider cryptographyProvider,
+                                         SecureString encryptionKey,
+                                         SaveFilter saveFilter) : ISerializer<ConnectionInfo, XElement>
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly SecureString _encryptionKey;
-        private readonly SaveFilter _saveFilter;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
+        private readonly SecureString _encryptionKey = encryptionKey ?? throw new ArgumentNullException(nameof(encryptionKey));
+        private readonly SaveFilter _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
 
         public Version Version { get; } = new Version(2, 7);
 
-        public XmlConnectionNodeSerializer27(ICryptographyProvider cryptographyProvider,
-                                             SecureString encryptionKey,
-                                             SaveFilter saveFilter)
-        {
-            _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
-            _encryptionKey = encryptionKey ?? throw new ArgumentNullException(nameof(encryptionKey));
-            _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
-        }
-
         public XElement Serialize(ConnectionInfo connectionInfo)
         {
             XElement element = new(XName.Get("Node", ""));

mRemoteNG/Config/Serializers/ConnectionSerializers/Xml/XmlConnectionNodeSerializer28.cs

@@ -11,23 +11,16 @@ namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Xml
 {
     // ReSharper disable once InconsistentNaming
     [SupportedOSPlatform("windows")]
-    public class XmlConnectionNodeSerializer28 : ISerializer<ConnectionInfo, XElement>
+    public class XmlConnectionNodeSerializer28(ICryptographyProvider cryptographyProvider,
+                                         SecureString encryptionKey,
+                                         SaveFilter saveFilter) : ISerializer<ConnectionInfo, XElement>
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly SecureString _encryptionKey;
-        private readonly SaveFilter _saveFilter;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
+        private readonly SecureString _encryptionKey = encryptionKey ?? throw new ArgumentNullException(nameof(encryptionKey));
+        private readonly SaveFilter _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
 
         public Version Version { get; } = new Version(2, 8);
 
-        public XmlConnectionNodeSerializer28(ICryptographyProvider cryptographyProvider,
-                                             SecureString encryptionKey,
-                                             SaveFilter saveFilter)
-        {
-            _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
-            _encryptionKey = encryptionKey ?? throw new ArgumentNullException(nameof(encryptionKey));
-            _saveFilter = saveFilter ?? throw new ArgumentNullException(nameof(saveFilter));
-        }
-
         public XElement Serialize(ConnectionInfo connectionInfo)
         {
             XElement element = new(XName.Get("Node", ""));

mRemoteNG/Config/Serializers/ConnectionSerializers/Xml/XmlConnectionsDocumentCompiler.cs

@@ -12,17 +12,11 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Xml
 {
     [SupportedOSPlatform("windows")]
-    public class XmlConnectionsDocumentCompiler
+    public class XmlConnectionsDocumentCompiler(ICryptographyProvider cryptographyProvider, ISerializer<ConnectionInfo, XElement> connectionNodeSerializer)
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
         private SecureString _encryptionKey;
-        private readonly ISerializer<ConnectionInfo, XElement> _connectionNodeSerializer;
-
-        public XmlConnectionsDocumentCompiler(ICryptographyProvider cryptographyProvider, ISerializer<ConnectionInfo, XElement> connectionNodeSerializer)
-        {
-            _cryptographyProvider = cryptographyProvider ?? throw new ArgumentNullException(nameof(cryptographyProvider));
-            _connectionNodeSerializer = connectionNodeSerializer ?? throw new ArgumentNullException(nameof(connectionNodeSerializer));
-        }
+        private readonly ISerializer<ConnectionInfo, XElement> _connectionNodeSerializer = connectionNodeSerializer ?? throw new ArgumentNullException(nameof(connectionNodeSerializer));
 
         public XDocument CompileDocument(ConnectionTreeModel connectionTreeModel, bool fullFileEncryption)
         {

mRemoteNG/Config/Serializers/ConnectionSerializers/Xml/XmlConnectionsDocumentEncryptor.cs

@@ -4,14 +4,9 @@ using mRemoteNG.Security;
 
 namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Xml
 {
-    public class XmlConnectionsDocumentEncryptor
+    public class XmlConnectionsDocumentEncryptor(ICryptographyProvider cryptographyProvider)
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-
-        public XmlConnectionsDocumentEncryptor(ICryptographyProvider cryptographyProvider)
-        {
-            _cryptographyProvider = cryptographyProvider;
-        }
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider;
 
         public XDocument EncryptDocument(XDocument documentToEncrypt, SecureString encryptionKey)
         {

mRemoteNG/Config/Serializers/ConnectionSerializers/Xml/XmlConnectionsSerializer.cs

@@ -14,22 +14,16 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Serializers.ConnectionSerializers.Xml
 {
     [SupportedOSPlatform("windows")]
-    public class XmlConnectionsSerializer : ISerializer<ConnectionTreeModel, string>,
+    public class XmlConnectionsSerializer(ICryptographyProvider cryptographyProvider,
+                                    ISerializer<ConnectionInfo, XElement> connectionNodeSerializer) : ISerializer<ConnectionTreeModel, string>,
                                             ISerializer<ConnectionInfo, string>
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly ISerializer<ConnectionInfo, XElement> _connectionNodeSerializer;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider;
+        private readonly ISerializer<ConnectionInfo, XElement> _connectionNodeSerializer = connectionNodeSerializer;
 
         public Version Version => _connectionNodeSerializer.Version;
         public bool UseFullEncryption { get; set; }
 
-        public XmlConnectionsSerializer(ICryptographyProvider cryptographyProvider,
-                                        ISerializer<ConnectionInfo, XElement> connectionNodeSerializer)
-        {
-            _cryptographyProvider = cryptographyProvider;
-            _connectionNodeSerializer = connectionNodeSerializer;
-        }
-
         public string Serialize(ConnectionTreeModel connectionTreeModel)
         {
             RootNodeInfo rootNode = (RootNodeInfo)connectionTreeModel.RootNodes.First(node => node is RootNodeInfo);

mRemoteNG/Config/Serializers/MiscSerializers/ActiveDirectoryDeserializer.cs

@@ -15,16 +15,10 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.MiscSerializers
 {
     [SupportedOSPlatform("windows")]
-    public class ActiveDirectoryDeserializer
+    public class ActiveDirectoryDeserializer(string ldapPath, bool importSubOu)
     {
-        private readonly string _ldapPath;
-        private readonly bool _importSubOu;
-
-        public ActiveDirectoryDeserializer(string ldapPath, bool importSubOu)
-        {
-            _ldapPath = ldapPath.ThrowIfNullOrEmpty(nameof(ldapPath));
-            _importSubOu = importSubOu;
-        }
+        private readonly string _ldapPath = ldapPath.ThrowIfNullOrEmpty(nameof(ldapPath));
+        private readonly bool _importSubOu = importSubOu;
 
         public ConnectionTreeModel Deserialize()
         {

mRemoteNG/Config/Serializers/MiscSerializers/PortScanDeserializer.cs

@@ -10,14 +10,9 @@ using mRemoteNG.Tree.Root;
 namespace mRemoteNG.Config.Serializers.MiscSerializers
 {
     [SupportedOSPlatform("windows")]
-    public class PortScanDeserializer : IDeserializer<IEnumerable<ScanHost>, ConnectionTreeModel>
+    public class PortScanDeserializer(ProtocolType targetProtocolType) : IDeserializer<IEnumerable<ScanHost>, ConnectionTreeModel>
     {
-        private readonly ProtocolType _targetProtocolType;
-
-        public PortScanDeserializer(ProtocolType targetProtocolType)
-        {
-            _targetProtocolType = targetProtocolType;
-        }
+        private readonly ProtocolType _targetProtocolType = targetProtocolType;
 
         public ConnectionTreeModel Deserialize(IEnumerable<ScanHost> scannedHosts)
         {

mRemoteNG/Config/Serializers/Versioning/SqlDatabaseVersionVerifier.cs

@@ -9,16 +9,11 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlDatabaseVersionVerifier
+    public class SqlDatabaseVersionVerifier(IDatabaseConnector databaseConnector)
     {
         private readonly Version _currentSupportedVersion = new(3, 0);
 
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlDatabaseVersionVerifier(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool VerifyDatabaseVersion(Version dbVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion22To23Upgrader.cs

@@ -7,14 +7,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion22To23Upgrader : IVersionUpgrader
+    public class SqlVersion22To23Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion22To23Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion23To24Upgrader.cs

@@ -7,14 +7,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion23To24Upgrader : IVersionUpgrader
+    public class SqlVersion23To24Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion23To24Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion24To25Upgrader.cs

@@ -7,14 +7,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion24To25Upgrader : IVersionUpgrader
+    public class SqlVersion24To25Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion24To25Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion25To26Upgrader.cs

@@ -7,14 +7,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion25To26Upgrader : IVersionUpgrader
+    public class SqlVersion25To26Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion25To26Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion26To27Upgrader.cs

@@ -8,14 +8,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion26To27Upgrader : IVersionUpgrader
+    public class SqlVersion26To27Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion26To27Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion27To28Upgrader.cs

@@ -9,14 +9,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion27To28Upgrader : IVersionUpgrader
+    public class SqlVersion27To28Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion27To28Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion28To29Upgrader.cs

@@ -8,15 +8,10 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion28To29Upgrader : IVersionUpgrader
+    public class SqlVersion28To29Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
         private readonly Version _version = new(2, 9);
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion28To29Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Serializers/Versioning/SqlVersion29To30Upgrader.cs

@@ -8,15 +8,10 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Config.Serializers.Versioning
 {
     [SupportedOSPlatform("windows")]
-    public class SqlVersion29To30Upgrader : IVersionUpgrader
+    public class SqlVersion29To30Upgrader(IDatabaseConnector databaseConnector) : IVersionUpgrader
     {
         private readonly Version _version = new(3, 0);
-        private readonly IDatabaseConnector _databaseConnector;
-
-        public SqlVersion29To30Upgrader(IDatabaseConnector databaseConnector)
-        {
-            _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
-        }
+        private readonly IDatabaseConnector _databaseConnector = databaseConnector ?? throw new ArgumentNullException(nameof(databaseConnector));
 
         public bool CanUpgrade(Version currentVersion)
         {

mRemoteNG/Config/Settings/Providers/PortableSettingsProvider.cs

@@ -1,4 +1,4 @@
-// The MIT License (MIT)
+// The MIT License (MIT)
 //
 // Copyright(c) crdx
 // 

mRemoteNG/Connection/AbstractConnectionRecord.cs

@@ -14,7 +14,7 @@ using System.Security;
 namespace mRemoteNG.Connection
 {
     [SupportedOSPlatform("windows")]
-    public abstract class AbstractConnectionRecord : INotifyPropertyChanged
+    public abstract class AbstractConnectionRecord(string uniqueId) : INotifyPropertyChanged
     {
         #region Fields
 
@@ -829,7 +829,7 @@ namespace mRemoteNG.Connection
 
         #region Misc
 
-        [Browsable(false)] public string ConstantID { get; }
+        [Browsable(false)] public string ConstantID { get; } = uniqueId.ThrowIfNullOrEmpty(nameof(uniqueId));
 
         [LocalizedAttributes.LocalizedCategory(nameof(Language.Miscellaneous), 7),
          LocalizedAttributes.LocalizedDisplayName(nameof(Language.ExternalToolBefore)),
@@ -1032,20 +1032,14 @@ namespace mRemoteNG.Connection
         }
 
         #endregion
-
         #endregion
 
-        protected AbstractConnectionRecord(string uniqueId)
-        {
-            ConstantID = uniqueId.ThrowIfNullOrEmpty(nameof(uniqueId));
-        }
-
         protected virtual TPropertyType GetPropertyValue<TPropertyType>(string propertyName, TPropertyType value)
         {
             return (TPropertyType)GetType().GetProperty(propertyName)?.GetValue(this, null);
         }
 
-        public event PropertyChangedEventHandler PropertyChanged;
+        public event PropertyChangedEventHandler? PropertyChanged;
 
         protected virtual void RaisePropertyChangedEvent(object sender, PropertyChangedEventArgs args)
         {

mRemoteNG/Connection/ConnectionIcon.cs

@@ -12,22 +12,22 @@ namespace mRemoteNG.Connection
     {
         public static string[] Icons = { };
 
-        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
+        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext? context)
         {
             return new StandardValuesCollection(Icons);
         }
 
-        public override bool GetStandardValuesExclusive(ITypeDescriptorContext context)
+        public override bool GetStandardValuesExclusive(ITypeDescriptorContext? context)
         {
             return true;
         }
 
-        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
+        public override bool GetStandardValuesSupported(ITypeDescriptorContext? context)
         {
             return true;
         }
 
-        public static System.Drawing.Icon FromString(string iconName)
+        public static System.Drawing.Icon? FromString(string iconName)
         {
             try
             {
@@ -41,7 +41,7 @@ namespace mRemoteNG.Connection
             }
             catch (Exception ex)
             {
-                Runtime.MessageCollector.AddMessage(Messages.MessageClass.ErrorMsg, $"Couldn\'t get Icon from String" + Environment.NewLine + ex.Message);
+                Runtime.MessageCollector.AddMessage(Messages.MessageClass.ErrorMsg, $"Couldn't get Icon from String" + Environment.NewLine + ex.Message);
             }
 
             return null;

mRemoteNG/Connection/ConnectionInfoComparer.cs

@@ -6,18 +6,17 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Connection
 {
     [SupportedOSPlatform("windows")]
-    public class ConnectionInfoComparer<TProperty> : IComparer<ConnectionInfo> where TProperty : IComparable<TProperty>
+    public class ConnectionInfoComparer<TProperty>(Func<ConnectionInfo, TProperty> sortExpression) : IComparer<ConnectionInfo> where TProperty : IComparable<TProperty>
     {
-        private readonly Func<ConnectionInfo, TProperty> _sortExpression;
+        private readonly Func<ConnectionInfo, TProperty> _sortExpression = sortExpression;
         public ListSortDirection SortDirection { get; set; } = ListSortDirection.Ascending;
 
-        public ConnectionInfoComparer(Func<ConnectionInfo, TProperty> sortExpression)
+        public int Compare(ConnectionInfo? x, ConnectionInfo? y)
         {
-            _sortExpression = sortExpression;
-        }
+            if (x == null && y == null) return 0;
+            if (x == null) return SortDirection == ListSortDirection.Ascending ? -1 : 1;
+            if (y == null) return SortDirection == ListSortDirection.Ascending ? 1 : -1;
 
-        public int Compare(ConnectionInfo x, ConnectionInfo y)
-        {
             return SortDirection == ListSortDirection.Ascending ? CompareAscending(x, y) : CompareDescending(x, y);
         }
 

mRemoteNG/Connection/ConnectionsService.cs

@@ -23,12 +23,12 @@ using mRemoteNG.Config.Serializers.ConnectionSerializers.Sql;
 namespace mRemoteNG.Connection
 {
     [SupportedOSPlatform("windows")]
-    public class ConnectionsService
+    public class ConnectionsService(PuttySessionsManager puttySessionsManager)
     {
         private static readonly object SaveLock = new();
-        private readonly PuttySessionsManager _puttySessionsManager;
-        private readonly IDataProvider<string> _localConnectionPropertiesDataProvider;
-        private readonly LocalConnectionPropertiesXmlSerializer _localConnectionPropertiesSerializer;
+        private readonly PuttySessionsManager _puttySessionsManager = puttySessionsManager ?? throw new ArgumentNullException(nameof(puttySessionsManager));
+        private readonly IDataProvider<string> _localConnectionPropertiesDataProvider = new FileDataProvider(Path.Combine(SettingsFileInfo.SettingsPath, SettingsFileInfo.LocalConnectionProperties));
+        private readonly LocalConnectionPropertiesXmlSerializer _localConnectionPropertiesSerializer = new LocalConnectionPropertiesXmlSerializer();
         private bool _batchingSaves = false;
         private bool _saveRequested = false;
         private bool _saveAsyncRequested = false;
@@ -42,13 +42,6 @@ namespace mRemoteNG.Connection
 
         public ConnectionTreeModel ConnectionTreeModel { get; private set; }
 
-        public ConnectionsService(PuttySessionsManager puttySessionsManager)
-        {
-            _puttySessionsManager = puttySessionsManager ?? throw new ArgumentNullException(nameof(puttySessionsManager));
-            _localConnectionPropertiesDataProvider = new FileDataProvider(Path.Combine(SettingsFileInfo.SettingsPath, SettingsFileInfo.LocalConnectionProperties));
-            _localConnectionPropertiesSerializer = new LocalConnectionPropertiesXmlSerializer();
-        }
-
         public void NewConnectionsFile(string filename)
         {
             try

mRemoteNG/Connection/InterfaceControl.Designer.cs

@@ -1,4 +1,4 @@
-namespace mRemoteNG.Connection
+namespace mRemoteNG.Connection
 {
     public sealed partial class InterfaceControl : System.Windows.Forms.Panel
 	{
@@ -21,14 +21,11 @@ namespace mRemoteNG.Connection
 			
 		//Required by the Windows Form Designer
 		private System.ComponentModel.Container components = null;
-			
-		//NOTE: The following procedure is required by the Windows Form Designer
-		//It can be modified using the Windows Form Designer.
-		//Do not modify it using the code editor.
-		[System.Diagnostics.DebuggerStepThrough()]
-        private void InitializeComponent()
-		{
-			components = new System.ComponentModel.Container();
-		}
-	}
+
+        //NOTE: The following procedure is required by the Windows Form Designer
+        //It can be modified using the Windows Form Designer.
+        //Do not modify it using the code editor.
+        [System.Diagnostics.DebuggerStepThrough()]
+        private void InitializeComponent() => components = new System.ComponentModel.Container();
+    }
 }

mRemoteNG/Connection/Protocol/ProtocolList.cs

@@ -1,11 +1,13 @@
 using System;
 using System.Collections;
 using System.Collections.Specialized;
+using System.Runtime.Versioning;
 
 // ReSharper disable ArrangeAccessorOwnerBody
 
 namespace mRemoteNG.Connection.Protocol
 {
+    [SupportedOSPlatform("windows")]
     public class ProtocolList : CollectionBase, INotifyCollectionChanged
     {
         public ProtocolBase this[object index]
@@ -23,7 +25,6 @@ namespace mRemoteNG.Connection.Protocol
 
         public new int Count => List.Count;
 
-
         public void Add(ProtocolBase cProt)
         {
             List.Add(cProt);
@@ -64,7 +65,7 @@ namespace mRemoteNG.Connection.Protocol
             RaiseCollectionChangedEvent(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
         }
 
-        public event NotifyCollectionChangedEventHandler CollectionChanged;
+        public event NotifyCollectionChangedEventHandler? CollectionChanged; // Fix for CS8612: Declare the event as nullable to match the interface.
 
         private void RaiseCollectionChangedEvent(object sender, NotifyCollectionChangedEventArgs args)
         {

mRemoteNG/Connection/PuttySessionInfo.cs

@@ -19,11 +19,11 @@ namespace mRemoteNG.Connection
 
         [Browsable(false)] public RootPuttySessionsNodeInfo RootRootPuttySessionsInfo { get; set; }
 
-        [ReadOnly(true)] public override string PuttySession { get; set; }
+        [ReadOnly(true)] public override string PuttySession { get; set; } = string.Empty;
 
-        [ReadOnly(true)] public override string Name { get; set; }
+        [ReadOnly(true)] public override string Name { get; set; } = string.Empty;
 
-        [ReadOnly(true), Browsable(false)] public override string Description { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string Description { get; set; } = string.Empty;
 
         [ReadOnly(true), Browsable(false)]
         public override string Icon
@@ -39,24 +39,24 @@ namespace mRemoteNG.Connection
             set { }
         }
 
-        [ReadOnly(true)] public override string Hostname { get; set; }
+        [ReadOnly(true)] public override string Hostname { get; set; } = string.Empty;
 
-        [ReadOnly(true)] public override string Username { get; set; }
+        [ReadOnly(true)] public override string Username { get; set; } = string.Empty;
 
         //[ReadOnly(true), Browsable(false)] public override SecureString Password { get; set; }
-        [ReadOnly(true), Browsable(false)] public override string Password { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string Password { get; set; } = string.Empty;
 
         [ReadOnly(true)] public override ProtocolType Protocol { get; set; }
 
         [ReadOnly(true)] public override int Port { get; set; }
 
-        [ReadOnly(true), Browsable(false)] public override string PreExtApp { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string PreExtApp { get; set; } = string.Empty;
 
-        [ReadOnly(true), Browsable(false)] public override string PostExtApp { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string PostExtApp { get; set; } = string.Empty;
 
-        [ReadOnly(true), Browsable(false)] public override string MacAddress { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string MacAddress { get; set; } = string.Empty;
 
-        [ReadOnly(true), Browsable(false)] public override string UserField { get; set; }
+        [ReadOnly(true), Browsable(false)] public override string UserField { get; set; } = string.Empty;
 
         #endregion
 

mRemoteNG/Container/ContainerInfo.cs

@@ -313,7 +313,7 @@ namespace mRemoteNG.Container
             childAsContainer.CollectionChanged -= RaiseCollectionChangedEvent;
         }
 
-        public event NotifyCollectionChangedEventHandler CollectionChanged;
+        public event NotifyCollectionChangedEventHandler? CollectionChanged;
 
         private void RaiseCollectionChangedEvent(object sender, NotifyCollectionChangedEventArgs args)
         {

mRemoteNG/Credential/CredentialDomainUserComparer.cs

@@ -1,18 +1,24 @@
 using System.Collections;
 using System.Collections.Generic;
+using System.Runtime.Versioning;
 
 
 namespace mRemoteNG.Credential
 {
+    [SupportedOSPlatform("windows")]
     public class CredentialDomainUserComparer : IComparer<ICredentialRecord>, IEqualityComparer<ICredentialRecord>
     {
-        public int Compare(ICredentialRecord x, ICredentialRecord y)
+        public int Compare(ICredentialRecord? x, ICredentialRecord? y)
         {
+            if (x == null && y == null) return 0;
+            if (x == null) return -1;
+            if (y == null) return 1;
+
             CaseInsensitiveComparer comparer = new();
             return comparer.Compare($"{x.Domain}\\{x.Username}", $"{y.Domain}\\{y.Username}");
         }
 
-        public bool Equals(ICredentialRecord x, ICredentialRecord y)
+        public bool Equals(ICredentialRecord? x, ICredentialRecord? y)
         {
             return Compare(x, y) == 0;
         }

mRemoteNG/Credential/CredentialRecord.cs

@@ -76,7 +76,7 @@ namespace mRemoteNG.Credential
             return Title;
         }
 
-        public event PropertyChangedEventHandler PropertyChanged;
+        public event PropertyChangedEventHandler? PropertyChanged;
 
         protected virtual void RaisePropertyChangedEvent(string propertyName)
         {

mRemoteNG/Credential/CredentialRecordTypeConverter.cs

@@ -11,17 +11,12 @@ namespace mRemoteNG.Credential
     [SupportedOSPlatform("windows")]
     public class CredentialRecordTypeConverter : TypeConverter
     {
-        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
+        public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
         {
             return sourceType == typeof(Guid) || base.CanConvertFrom(context, sourceType);
         }
 
-        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
-        {
-            return destinationType == typeof(Guid) || destinationType == typeof(ICredentialRecord) || base.CanConvertTo(context, destinationType);
-        }
-
-        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
+        public override object? ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
         {
             if (value is ICredentialRecord && destinationType == typeof(Guid))
                 return ((ICredentialRecord)value).Id;
@@ -30,7 +25,7 @@ namespace mRemoteNG.Credential
             return base.ConvertTo(context, culture, value, destinationType);
         }
 
-        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+        public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object value)
         {
             if (!(value is Guid)) return base.ConvertFrom(context, culture, value);
             ICredentialRecord[] matchedCredentials = Runtime.CredentialProviderCatalog.GetCredentialRecords()

mRemoteNG/Credential/PlaceholderCredentialRecord.cs

@@ -11,7 +11,7 @@ namespace mRemoteNG.Credential
     [SupportedOSPlatform("windows")]
     public class PlaceholderCredentialRecord(IEnumerable<Guid> id) : ICredentialRecord
     {
-        public event PropertyChangedEventHandler PropertyChanged;
+        public event PropertyChangedEventHandler? PropertyChanged;
 
         public Guid Id { get; } = id.FirstOrDefault();
 

mRemoteNG/Credential/Repositories/CredentialRepositoryConfig.cs

@@ -4,7 +4,7 @@ using System.Security;
 
 namespace mRemoteNG.Credential.Repositories
 {
-    public class CredentialRepositoryConfig : ICredentialRepositoryConfig
+    public class CredentialRepositoryConfig(Guid id) : ICredentialRepositoryConfig
     {
         private string _title = "New Credential Repository";
         private string _source = "";
@@ -12,7 +12,7 @@ namespace mRemoteNG.Credential.Repositories
         private string _typeName = "";
         private bool _loaded;
 
-        public Guid Id { get; }
+        public Guid Id { get; } = id;
 
         public string Title
         {
@@ -68,12 +68,7 @@ namespace mRemoteNG.Credential.Repositories
         {
         }
 
-        public CredentialRepositoryConfig(Guid id)
-        {
-            Id = id;
-        }
-
-        public event PropertyChangedEventHandler PropertyChanged;
+        public event PropertyChangedEventHandler? PropertyChanged;
 
         protected virtual void RaisePropertyChangedEvent(string propertyName)
         {

mRemoteNG/Messages/Message.cs

@@ -1,20 +1,12 @@
-using System;
+using System;
 
 namespace mRemoteNG.Messages
 {
-    public class Message : IMessage
+    public class Message(MessageClass messageClass, string messageText, bool onlyLog = false) : IMessage
     {
-        public MessageClass Class { get; set; }
-        public string Text { get; set; }
-        public DateTime Date { get; set; }
-        public bool OnlyLog { get; set; }
-
-        public Message(MessageClass messageClass, string messageText, bool onlyLog = false)
-        {
-            Class = messageClass;
-            Text = messageText;
-            Date = DateTime.Now;
-            OnlyLog = onlyLog;
-        }
+        public MessageClass Class { get; set; } = messageClass;
+        public string Text { get; set; } = messageText;
+        public DateTime Date { get; set; } = DateTime.Now;
+        public bool OnlyLog { get; set; } = onlyLog;
     }
 }

mRemoteNG/Messages/MessageCollector.cs

@@ -63,7 +63,7 @@ namespace mRemoteNG.Messages
             _messageList.Clear();
         }
 
-        public event NotifyCollectionChangedEventHandler CollectionChanged;
+        public event NotifyCollectionChangedEventHandler? CollectionChanged;
 
         private void RaiseCollectionChangedEvent(NotifyCollectionChangedAction action, IList items)
         {

mRemoteNG/Messages/MessageWriters/NotificationPanelMessageWriter.cs

@@ -7,14 +7,9 @@ using mRemoteNG.UI.Window;
 namespace mRemoteNG.Messages.MessageWriters
 {
     [SupportedOSPlatform("windows")]
-    public class NotificationPanelMessageWriter : IMessageWriter
+    public class NotificationPanelMessageWriter(ErrorAndInfoWindow messageWindow) : IMessageWriter
     {
-        private readonly ErrorAndInfoWindow _messageWindow;
-
-        public NotificationPanelMessageWriter(ErrorAndInfoWindow messageWindow)
-        {
-            _messageWindow = messageWindow ?? throw new ArgumentNullException(nameof(messageWindow));
-        }
+        private readonly ErrorAndInfoWindow _messageWindow = messageWindow ?? throw new ArgumentNullException(nameof(messageWindow));
 
         public void Write(IMessage message)
         {

mRemoteNG/Messages/MessageWriters/TextLogMessageWriter.cs

@@ -5,14 +5,9 @@ using mRemoteNG.App;
 namespace mRemoteNG.Messages.MessageWriters
 {
     [SupportedOSPlatform("windows")]
-    public class TextLogMessageWriter : IMessageWriter
+    public class TextLogMessageWriter(Logger logger) : IMessageWriter
     {
-        private readonly Logger _logger;
-
-        public TextLogMessageWriter(Logger logger)
-        {
-            _logger = logger ?? throw new ArgumentNullException(nameof(logger));
-        }
+        private readonly Logger _logger = logger ?? throw new ArgumentNullException(nameof(logger));
 
         public void Write(IMessage message)
         {

mRemoteNG/Messages/WriterDecorators/MessageFocusDecorator.cs

@@ -11,20 +11,13 @@ using WeifenLuo.WinFormsUI.Docking;
 namespace mRemoteNG.Messages.WriterDecorators
 {
     [SupportedOSPlatform("windows")]
-    public class MessageFocusDecorator : IMessageWriter
+    public class MessageFocusDecorator(ErrorAndInfoWindow messageWindow, IMessageTypeFilteringOptions filter, IMessageWriter decoratedWriter) : IMessageWriter
     {
-        private readonly IMessageTypeFilteringOptions _filter;
-        private readonly IMessageWriter _decoratedWriter;
-        private readonly ErrorAndInfoWindow _messageWindow;
+        private readonly IMessageTypeFilteringOptions _filter = filter ?? throw new ArgumentNullException(nameof(filter));
+        private readonly IMessageWriter _decoratedWriter = decoratedWriter ?? throw new ArgumentNullException(nameof(decoratedWriter));
+        private readonly ErrorAndInfoWindow _messageWindow = messageWindow ?? throw new ArgumentNullException(nameof(messageWindow));
         private readonly FrmMain _frmMain = FrmMain.Default;
 
-        public MessageFocusDecorator(ErrorAndInfoWindow messageWindow, IMessageTypeFilteringOptions filter, IMessageWriter decoratedWriter)
-        {
-            _filter = filter ?? throw new ArgumentNullException(nameof(filter));
-            _messageWindow = messageWindow ?? throw new ArgumentNullException(nameof(messageWindow));
-            _decoratedWriter = decoratedWriter ?? throw new ArgumentNullException(nameof(decoratedWriter));
-        }
-
         public async void Write(IMessage message)
         {
             _decoratedWriter.Write(message);

mRemoteNG/Properties/AssemblyInfo.cs

@@ -18,10 +18,10 @@ using System.Resources;
 [assembly: AssemblyCulture("")]
 
 // Version information
-[assembly: AssemblyVersion("1.78.2.3028")]
-[assembly: AssemblyFileVersion("1.78.2.3028")]
+[assembly: AssemblyVersion("1.78.2.3038")]
+[assembly: AssemblyFileVersion("1.78.2.3038")]
 [assembly: NeutralResourcesLanguageAttribute("en-US")]
-[assembly: AssemblyInformationalVersion("1.78.2 (Nightly Build 3028)")]
+[assembly: AssemblyInformationalVersion("1.78.2 (Nightly Build 3038)")]
 
 // Logging
 [assembly: log4net.Config.XmlConfigurator(ConfigFile = "log4net.config")]

mRemoteNG/Security/Authentication/PasswordAuthenticator.cs

@@ -5,24 +5,17 @@ using mRemoteNG.Tools;
 
 namespace mRemoteNG.Security.Authentication
 {
-    public class PasswordAuthenticator : IAuthenticator
+    public class PasswordAuthenticator(ICryptographyProvider cryptographyProvider,
+                                 string cipherText,
+                                 Func<Optional<SecureString>> authenticationRequestor) : IAuthenticator
     {
-        private readonly ICryptographyProvider _cryptographyProvider;
-        private readonly string _cipherText;
-        private readonly Func<Optional<SecureString>> _authenticationRequestor;
+        private readonly ICryptographyProvider _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
+        private readonly string _cipherText = cipherText.ThrowIfNullOrEmpty(nameof(cipherText));
+        private readonly Func<Optional<SecureString>> _authenticationRequestor = authenticationRequestor.ThrowIfNull(nameof(authenticationRequestor));
 
         public int MaxAttempts { get; set; } = 3;
         public SecureString LastAuthenticatedPassword { get; private set; }
 
-        public PasswordAuthenticator(ICryptographyProvider cryptographyProvider,
-                                     string cipherText,
-                                     Func<Optional<SecureString>> authenticationRequestor)
-        {
-            _cryptographyProvider = cryptographyProvider.ThrowIfNull(nameof(cryptographyProvider));
-            _cipherText = cipherText.ThrowIfNullOrEmpty(nameof(cipherText));
-            _authenticationRequestor = authenticationRequestor.ThrowIfNull(nameof(authenticationRequestor));
-        }
-
         public bool Authenticate(SecureString password)
         {
             bool authenticated = false;

mRemoteNG/Themes/ExtendedColorPalette.cs

@@ -6,17 +6,11 @@ namespace mRemoteNG.Themes
     /// <summary>
     /// Class used for the UI to display the color tables,as the Dictionary value keys cannot be directly replaced
     /// </summary>
-    public class PseudoKeyColor
+    public class PseudoKeyColor(string _key, Color _value)
     {
-        public PseudoKeyColor(string _key, Color _value)
-        {
-            Key = _key;
-            Value = _value;
-        }
+        public string Key { get; set; } = _key;
 
-        public string Key { get; set; }
-
-        public Color Value { get; set; }
+        public Color Value { get; set; } = _value;
     }
 
 

mRemoteNG/Tools/ADhelper.cs

@@ -7,19 +7,13 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Tools
 {
     [SupportedOSPlatform("windows")]
-    public class AdHelper
+    public class AdHelper(string domain)
     {
         private DirectoryEntry _dEntry;
 
-        public AdHelper(string domain)
-        {
-            Children = [];
-            Domain = domain;
-        }
+        public Hashtable Children { get; } = [];
 
-        public Hashtable Children { get; }
-
-        private string Domain { get; }
+        private string Domain { get; } = domain;
 
         public void GetChildEntries(string adPath = "")
         {

mRemoteNG/Tools/Attributes/AttributeUsedInAllProtocolsExcept.cs

@@ -4,15 +4,11 @@ using mRemoteNG.Connection.Protocol;
 
 namespace mRemoteNG.Tools.Attributes
 {
-    public class AttributeUsedInAllProtocolsExcept : AttributeUsedInProtocol
-    {
-        public AttributeUsedInAllProtocolsExcept(params ProtocolType[] exceptions)
-            : base(Enum
+    public class AttributeUsedInAllProtocolsExcept(params ProtocolType[] exceptions) : AttributeUsedInProtocol(Enum
                 .GetValues(typeof(ProtocolType))
                 .Cast<ProtocolType>()
                 .Except(exceptions)
                 .ToArray())
-        {
-        }
+    {
     }
 }

mRemoteNG/Tools/Attributes/AttributeUsedInProtocol.cs

@@ -4,13 +4,8 @@ using mRemoteNG.Connection.Protocol;
 namespace mRemoteNG.Tools.Attributes
 {
     [AttributeUsage(AttributeTargets.Property)]
-    public class AttributeUsedInProtocol : Attribute
+    public class AttributeUsedInProtocol(params ProtocolType[] supportedProtocolTypes) : Attribute
     {
-        public ProtocolType[] SupportedProtocolTypes { get; }
-
-        public AttributeUsedInProtocol(params ProtocolType[] supportedProtocolTypes)
-        {
-            SupportedProtocolTypes = supportedProtocolTypes;
-        }
+        public ProtocolType[] SupportedProtocolTypes { get; } = supportedProtocolTypes;
     }
 }

mRemoteNG/Tools/Authenticode.cs

@@ -1,12 +1,13 @@
-#if !PORTABLE
+#if !PORTABLE
 using System;
-using System.Windows.Forms;
-using System.IO;
-using System.Security.Cryptography.X509Certificates;
-using System.Runtime.InteropServices;
-using System.Security.Cryptography;
-using System.Reflection;
 using System.ComponentModel;
+using System.IO;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using System.Security.Cryptography;
+using System.Security.Cryptography.X509Certificates;
+using System.Windows.Forms;
 // ReSharper disable UnusedMember.Local
 // ReSharper disable NotAccessedField.Local
 // ReSharper disable UnusedAutoPropertyAccessor.Local
@@ -16,15 +17,10 @@ using System.ComponentModel;
 
 namespace mRemoteNG.Tools
 {
-	public class Authenticode
-	{
-        #region Public Methods
-		public Authenticode(string filePath)
-		{
-			FilePath = filePath;
-		}
-			
-		public StatusValue Verify()
+    [SupportedOSPlatform("windows")]
+    public class Authenticode(string filePath)
+    {
+        public StatusValue Verify()
 		{
             IntPtr trustFileInfoPointer = default(IntPtr);
             IntPtr trustDataPointer = default(IntPtr);
@@ -50,14 +46,17 @@ namespace mRemoteNG.Tools
 						return Status;
 					}
 
+                    //X509Certificate2 certificate2 = new(X509Certificate.CreateFromSignedFile(FilePath));
+
                     X509Certificate2 certificate2 = new(X509Certificate.CreateFromSignedFile(FilePath));
-					_thumbprint = certificate2.Thumbprint;
-					if (_thumbprint != ThumbprintToMatch)
-					{
-						Status = StatusValue.ThumbprintNotMatch;
-						return Status;
-					}
-				}
+                    _thumbprint = certificate2.Thumbprint;
+
+                    if (_thumbprint != ThumbprintToMatch)
+                    {
+                        Status = StatusValue.ThumbprintNotMatch;
+                        return Status;
+                    }
+                }
 
                 NativeMethods.WINTRUST_FILE_INFO trustFileInfo = new() { pcwszFilePath = FilePath};
 			    trustFileInfoPointer = Marshal.AllocCoTaskMem(Marshal.SizeOf(trustFileInfo));
@@ -78,8 +77,7 @@ namespace mRemoteNG.Tools
 
                 IntPtr windowHandle = DisplayParentForm?.Handle ?? IntPtr.Zero;
 					
-				_trustProviderErrorCode =
- NativeMethods.WinVerifyTrust(windowHandle, NativeMethods.WINTRUST_ACTION_GENERIC_VERIFY_V2, trustDataPointer);
+				_trustProviderErrorCode =  NativeMethods.WinVerifyTrust(windowHandle, NativeMethods.WINTRUST_ACTION_GENERIC_VERIFY_V2, trustDataPointer);
 			    // ReSharper disable once SwitchStatementMissingSomeCases
 				switch (_trustProviderErrorCode)
 				{
@@ -104,8 +102,7 @@ namespace mRemoteNG.Tools
 
 			    if (ex is CryptographicException)
 			    {
-                    PropertyInfo hResultProperty =
- ex.GetType().GetProperty("HResult", BindingFlags.NonPublic | BindingFlags.Instance);
+                    PropertyInfo? hResultProperty = ex.GetType().GetProperty("HResult", BindingFlags.NonPublic | BindingFlags.Instance);
 			        if (hResultProperty != null)
 			        {
                         int hResult = Convert.ToInt32(hResultProperty.GetValue(ex, null));
@@ -134,61 +131,54 @@ namespace mRemoteNG.Tools
 				}
 			}
 		}
-        #endregion
+        
 			
         #region Public Properties
 
 	    private DisplayValue Display { get; set; } = DisplayValue.None;
 
 	    private DisplayContextValue DisplayContext {get; set;}
-	    private Form DisplayParentForm {get; set;}
-	    internal Exception Exception {get; private set;}
-	    private string FilePath {get; set;}
+        private Form? DisplayParentForm { get; set; } = null; // Use nullable reference type
+        internal Exception? Exception { get; private set; } = null; // Set to null to satisfy non-nullable property
+        private string FilePath { get; set; } = filePath;
         internal bool RequireThumbprintMatch { get; set;}
 
 	    internal StatusValue Status { get; private set; }
 
-	    public string GetStatusMessage()
-	    {
-	        // ReSharper disable once SwitchStatementMissingSomeCases
-	        switch (Status)
-	        {
-	            case StatusValue.Verified:
-	                return "The file was verified successfully.";
-	            case StatusValue.FileNotExist:
-	                return "The specified file does not exist.";
-	            case StatusValue.FileEmpty:
-	                return "The specified file is empty.";
-	            case StatusValue.NoSignature:
-	                return "The specified file is not digitally signed.";
-	            case StatusValue.NoThumbprintToMatch:
-	                return "A thumbprint match is required but no thumbprint to match against was specified.";
-	            case StatusValue.ThumbprintNotMatch:
-	                /* (char)0x2260 == the "not equal to" symbol (which I cannot print in here without changing the encoding of the file)
-                     * Fancy...
-                     * 
-                     * "<>" is  fiarly cryptic for non-programers
-                     * So is "!="
-                     * "=/=" gets the job done, no?
-                     * What about plain old English (or localized value): X is not equal to Y?
-                     * :P
-                     */
-	                return $"The thumbprint does not match. {_thumbprint} {(char) 0x2260} {ThumbprintToMatch}.";
-	            case StatusValue.TrustProviderError:
+        public string GetStatusMessage()
+        {
+            // ReSharper disable once SwitchStatementMissingSomeCases
+            switch (Status)
+            {
+                case StatusValue.Verified:
+                    return "The file was verified successfully.";
+                case StatusValue.FileNotExist:
+                    return "The specified file does not exist.";
+                case StatusValue.FileEmpty:
+                    return "The specified file is empty.";
+                case StatusValue.NoSignature:
+                    return "The specified file is not digitally signed.";
+                case StatusValue.NoThumbprintToMatch:
+                    return "A thumbprint match is required but no thumbprint to match against was specified.";
+                case StatusValue.ThumbprintNotMatch:
+                    return $"The thumbprint does not match. {_thumbprint} {(char)0x2260} {ThumbprintToMatch}.";
+                case StatusValue.TrustProviderError:
                     Win32Exception ex = new(_trustProviderErrorCode);
-	                return $"The trust provider returned an error. {ex.Message}";
-	            case StatusValue.UnhandledException:
-	                return $"An unhandled exception occurred. {Exception.Message}";
-	            default:
-	                return "The status is unknown.";
-	        }
-	    }
+                    return $"The trust provider returned an error. {ex.Message}";
+                case StatusValue.UnhandledException:
+                    return Exception != null
+                        ? $"An unhandled exception occurred. {Exception.Message}"
+                        : "An unhandled exception occurred, but no exception details are available.";
+                default:
+                    return "The status is unknown.";
+            }
+        }
 			
-		private string _thumbprint;
+		private string _thumbprint = string.Empty;
 
-        internal string ThumbprintToMatch { get; set;}
-			
-		private int _trustProviderErrorCode;
+        internal string ThumbprintToMatch { get; set; } = string.Empty; // Initialize to an empty string to satisfy non-nullable property
+
+        private int _trustProviderErrorCode;
 
 	    #endregion
 		

mRemoteNG/Tools/Cmdline/CommandLineArguments.cs

@@ -1,4 +1,4 @@
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Linq;
 using System.Text.RegularExpressions;
 
@@ -115,18 +115,11 @@ namespace mRemoteNG.Tools.Cmdline
 
         #region Protected Classes
 
-        protected class Argument
+        protected class Argument(string text, bool isFileName = false, bool forceQuotes = false)
         {
-            public Argument(string text, bool isFileName = false, bool forceQuotes = false)
-            {
-                Text = text;
-                IsFileName = isFileName;
-                ForceQuotes = forceQuotes;
-            }
-
-            public string Text { get; set; }
-            public bool IsFileName { get; set; }
-            public bool ForceQuotes { get; set; }
+            public string Text { get; set; } = text;
+            public bool IsFileName { get; set; } = isFileName;
+            public bool ForceQuotes { get; set; } = forceQuotes;
         }
 
         #endregion

mRemoteNG/Tools/DisposableOptional.cs

@@ -3,14 +3,9 @@ using System.Linq;
 
 namespace mRemoteNG.Tools
 {
-    public class DisposableOptional<T> : Optional<T>, IDisposable
+    public class DisposableOptional<T>(T value) : Optional<T>(value), IDisposable
         where T : IDisposable
     {
-        public DisposableOptional(T value)
-            : base(value)
-        {
-        }
-
         public void Dispose()
         {
             Dispose(true);

mRemoteNG/Tools/ExternalTool.cs

@@ -19,11 +19,11 @@ namespace mRemoteNG.Tools
     [SupportedOSPlatform("windows")]
     public class ExternalTool : INotifyPropertyChanged
     {
-        private string _displayName;
-        private string _fileName;
+        private string _displayName = string.Empty; // Initialize to avoid CS8618
+        private string _fileName = string.Empty; // Initialize to avoid CS8618
         private bool _waitForExit;
-        private string _arguments;
-        private string _workingDir;
+        private string _arguments = string.Empty; // Initialize to avoid CS8618
+        private string _workingDir = string.Empty; // Initialize to avoid CS8618
         private bool _tryIntegrate;
         private bool _showOnToolbar = true;
         private bool _runElevated;
@@ -90,9 +90,9 @@ namespace mRemoteNG.Tools
             set => SetField(ref _runElevated, value, nameof(RunElevated));
         }
 
-        public ConnectionInfo ConnectionInfo { get; set; }
+        public ConnectionInfo ConnectionInfo { get; set; } = new ConnectionInfo(); // Initialize to avoid CS8618
 
-        public Icon Icon => File.Exists(FileName) ? MiscTools.GetIconFromFile(FileName) : Properties.Resources.mRemoteNG_Icon;
+        public Icon Icon => File.Exists(FileName) ? MiscTools.GetIconFromFile(FileName) ?? Properties.Resources.mRemoteNG_Icon : Properties.Resources.mRemoteNG_Icon;
 
         public Image Image => Icon?.ToBitmap() ?? Properties.Resources.mRemoteNG_Icon.ToBitmap();
 
@@ -111,18 +111,17 @@ namespace mRemoteNG.Tools
             RunElevated = runElevated;
         }
 
-        public void Start(ConnectionInfo startConnectionInfo = null)
+        public void Start(ConnectionInfo startConnectionInfo = null!)
         {
             try
             {
                 if (string.IsNullOrEmpty(FileName))
                 {
-                    Runtime.MessageCollector.AddMessage(MessageClass.ErrorMsg,
-                                                        "ExternalApp.Start() failed: FileName cannot be blank.");
+                    Runtime.MessageCollector.AddMessage(MessageClass.ErrorMsg, "ExternalApp.Start() failed: FileName cannot be blank.");
                     return;
                 }
 
-                ConnectionInfo = startConnectionInfo;
+                ConnectionInfo = startConnectionInfo ?? new ConnectionInfo(); // Ensure ConnectionInfo is not null
                 if (startConnectionInfo is ContainerInfo container)
                 {
                     container.Children.ForEach(Start);
@@ -196,7 +195,7 @@ namespace mRemoteNG.Tools
             newConnectionInfo.Panel = Language._Tools;
         }
 
-        public event PropertyChangedEventHandler PropertyChanged;
+        public event PropertyChangedEventHandler? PropertyChanged = delegate { }; // Updated to match nullability
 
         protected virtual void RaisePropertyChangedEvent(object sender, string propertyName)
         {

mRemoteNG/Tools/ExternalToolArgumentParser.cs

@@ -11,14 +11,9 @@ using mRemoteNG.Tools.Cmdline;
 namespace mRemoteNG.Tools
 {
     [SupportedOSPlatform("windows")]
-    public class ExternalToolArgumentParser
+    public class ExternalToolArgumentParser(ConnectionInfo connectionInfo)
     {
-        private readonly ConnectionInfo _connectionInfo;
-
-        public ExternalToolArgumentParser(ConnectionInfo connectionInfo)
-        {
-            _connectionInfo = connectionInfo;
-        }
+        private readonly ConnectionInfo _connectionInfo = connectionInfo;
 
         public string ParseArguments(string input)
         {
@@ -246,20 +241,13 @@ namespace mRemoteNG.Tools
             None
         }
 
-        private struct Replacement
+        private struct Replacement(int start, int length, string value)
         {
-            public int Start { get; }
+            public int Start { get; } = start;
 
-            public int Length { get; }
+            public int Length { get; } = length;
 
-            public string Value { get; }
-
-            public Replacement(int start, int length, string value)
-            {
-                Start = start;
-                Length = length;
-                Value = value;
-            }
+            public string Value { get; } = value;
         }
     }
 }

mRemoteNG/Tools/ExternalToolsTypeConverter.cs

@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.Versioning;
 
 namespace mRemoteNG.Tools
@@ -26,18 +27,33 @@ namespace mRemoteNG.Tools
             }
         }
 
-        public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
+        public override StandardValuesCollection GetStandardValues([NotNull] ITypeDescriptorContext? context)
         {
+            if (context == null)
+            {
+                throw new System.ArgumentNullException(nameof(context));
+            }
+
             return new StandardValuesCollection(ExternalTools);
         }
 
-        public override bool GetStandardValuesExclusive(System.ComponentModel.ITypeDescriptorContext context)
+        public override bool GetStandardValuesExclusive([NotNull] ITypeDescriptorContext? context)
         {
+            if (context == null)
+            {
+                throw new System.ArgumentNullException(nameof(context));
+            }
+
             return true;
         }
 
-        public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
+        public override bool GetStandardValuesSupported([NotNull] ITypeDescriptorContext? context)
         {
+            if (context == null)
+            {
+                throw new System.ArgumentNullException(nameof(context));
+            }
+
             return true;
         }
     }

mRemoteNG/Tools/MiscTools.cs

@@ -18,36 +18,32 @@ namespace mRemoteNG.Tools
     [SupportedOSPlatform("windows")]
     public static class MiscTools
     {
-        public static Icon GetIconFromFile(string FileName)
+        public static Icon? GetIconFromFile(string FileName)
         {
             try
             {
-                return File.Exists(FileName) == false ? null : Icon.ExtractAssociatedIcon(FileName);
+                return File.Exists(FileName) ? Icon.ExtractAssociatedIcon(FileName) : null;
             }
             catch (ArgumentException AEx)
             {
-                Runtime.MessageCollector.AddMessage(MessageClass.WarningMsg,
-                                                    "GetIconFromFile failed (Tools.Misc) - using default icon" +
-                                                    Environment.NewLine + AEx.Message,
-                                                    true);
+                Runtime.MessageCollector.AddMessage(MessageClass.WarningMsg, "GetIconFromFile failed (Tools.Misc) - using default icon" + Environment.NewLine + AEx.Message, true);
                 return Properties.Resources.mRemoteNG_Icon;
             }
             catch (Exception ex)
             {
-                Runtime.MessageCollector.AddMessage(MessageClass.WarningMsg,
-                                                    "GetIconFromFile failed (Tools.Misc)" + Environment.NewLine +
-                                                    ex.Message, true);
+                Runtime.MessageCollector.AddMessage(MessageClass.WarningMsg, "GetIconFromFile failed (Tools.Misc)" + Environment.NewLine + ex.Message, true);
                 return null;
             }
         }
 
-        public static Optional<SecureString> PasswordDialog(string passwordName = null, bool verify = true)
+        public static Optional<SecureString> PasswordDialog(string? passwordName = null, bool verify = true)
         {
             //var splash = FrmSplashScreenNew.GetInstance();
             //TODO: something not right there 
             //if (PresentationSource.FromVisual(splash))
             //    splash.Close();
 
+            passwordName ??= string.Empty; // Ensure passwordName is not null
             FrmPassword passwordForm = new(passwordName, verify);
             return passwordForm.GetKey();
         }
@@ -139,7 +135,7 @@ namespace mRemoteNG.Tools
         }
 
 
-        public static Image TakeScreenshot(UI.Tabs.ConnectionTab sender)
+        public static Image? TakeScreenshot(UI.Tabs.ConnectionTab sender)
         {
             try
             {
@@ -159,74 +155,88 @@ namespace mRemoteNG.Tools
             return null;
         }
 
-        public class EnumTypeConverter : EnumConverter
+        public class EnumTypeConverter(Type type) : EnumConverter(type)
         {
-            private readonly Type _enumType;
+            private readonly Type _enumType = type;
 
-            public EnumTypeConverter(Type type) : base(type)
-            {
-                _enumType = type;
-            }
-
-            public override bool CanConvertTo(ITypeDescriptorContext context, Type destType)
+            public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destType)
             {
                 return destType == typeof(string);
             }
 
-            public override object ConvertTo(ITypeDescriptorContext context,
-                                             CultureInfo culture,
-                                             object value,
-                                             Type destType)
+            public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type? destType)
             {
-                if (value == null) return null;
-                System.Reflection.FieldInfo fi = _enumType.GetField(Enum.GetName(_enumType, value));
-                DescriptionAttribute dna = (DescriptionAttribute)Attribute.GetCustomAttribute(fi, typeof(DescriptionAttribute));
+                if (value == null) return string.Empty;
 
-                return dna != null ? dna.Description : value.ToString();
+                string? enumName = Enum.GetName(_enumType, value);
+                if (enumName == null)
+                {
+                    throw new ArgumentException("Invalid enum value provided.");
+                }
+
+                System.Reflection.FieldInfo? fi = _enumType.GetField(enumName);
+                if (fi == null)
+                {
+                    throw new ArgumentException("FieldInfo could not be retrieved for the provided enum value.");
+                }
+
+                DescriptionAttribute? dna = (DescriptionAttribute?)Attribute.GetCustomAttribute(fi, typeof(DescriptionAttribute));
+                return dna?.Description ?? value.ToString() ?? string.Empty;
             }
 
-            public override bool CanConvertFrom(ITypeDescriptorContext context, Type srcType)
+            public override bool CanConvertFrom(ITypeDescriptorContext? context, Type? srcType)
             {
                 return srcType == typeof(string);
             }
 
-            public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+            public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object? value)
             {
-                foreach (System.Reflection.FieldInfo fi in _enumType.GetFields())
+                if (value is string stringValue)
                 {
-                    DescriptionAttribute dna = (DescriptionAttribute)Attribute.GetCustomAttribute(fi, typeof(DescriptionAttribute));
-
-                    if (dna != null && (string)value == dna.Description)
+                    foreach (System.Reflection.FieldInfo fi in _enumType.GetFields())
                     {
-                        return Enum.Parse(_enumType, fi.Name);
+                        DescriptionAttribute? dna = (DescriptionAttribute?)Attribute.GetCustomAttribute(fi, typeof(DescriptionAttribute));
+
+                        if (dna != null && string.Equals(stringValue, dna.Description, StringComparison.Ordinal))
+                        {
+                            return Enum.Parse(_enumType, fi.Name);
+                        }
                     }
+
+                    return Enum.Parse(_enumType, stringValue);
                 }
 
-                return value != null ? Enum.Parse(_enumType, (string)value) : null;
+                throw new ArgumentNullException(nameof(value), "Value cannot be null.");
             }
         }
 
         public class YesNoTypeConverter : TypeConverter
         {
-            public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
+            public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
             {
                 return sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
             }
-
-            public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+            public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
             {
                 return destinationType == typeof(string) || base.CanConvertTo(context, destinationType);
             }
 
-            public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+            public override object? ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object? value)
             {
-                if (!(value is string)) return base.ConvertFrom(context, culture, value);
-                if (string.Equals(value.ToString(), Language.Yes, StringComparison.CurrentCultureIgnoreCase))
+                if (value is not string stringValue)
+                {
+                    // Ensure 'value' is not null before passing it to the base method
+                    return value != null
+                        ? base.ConvertFrom(context, culture, value)
+                        : throw new ArgumentNullException(nameof(value), "Value cannot be null.");
+                }
+
+                if (string.Equals(stringValue, Language.Yes, StringComparison.CurrentCultureIgnoreCase))
                 {
                     return true;
                 }
 
-                if (string.Equals(value.ToString(), Language.No, StringComparison.CurrentCultureIgnoreCase))
+                if (string.Equals(stringValue, Language.No, StringComparison.CurrentCultureIgnoreCase))
                 {
                     return false;
                 }
@@ -234,27 +244,24 @@ namespace mRemoteNG.Tools
                 throw new Exception("Values must be \"Yes\" or \"No\"");
             }
 
-            public override object ConvertTo(ITypeDescriptorContext context,
-                                             CultureInfo culture,
-                                             object value,
-                                             Type destinationType)
+            public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
             {
                 if (destinationType == typeof(string))
                 {
                     return Convert.ToBoolean(value) ? Language.Yes : Language.No;
                 }
 
-                return base.ConvertTo(context, culture, value, destinationType);
+                return base.ConvertTo(context, culture, value, destinationType) ?? throw new InvalidOperationException("Base conversion returned null.");
             }
 
-            public override bool GetStandardValuesSupported(ITypeDescriptorContext context)
+            public override bool GetStandardValuesSupported(ITypeDescriptorContext? context)
             {
                 return true;
             }
 
-            public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext context)
+            public override StandardValuesCollection GetStandardValues(ITypeDescriptorContext? context)
             {
-                bool[] bools = {true, false};
+                bool[] bools = { true, false };
 
                 StandardValuesCollection svc = new(bools);
 

mRemoteNG/Tools/Optional.cs

@@ -35,7 +35,13 @@ namespace mRemoteNG.Tools
 
         public override string ToString()
         {
-            return _optional.Any() ? _optional.First().ToString() : "";
+            // Fixes CS8602 and CS8603 by ensuring null checks and returning a non-null value
+            if (_optional.Length > 0 && _optional[0] != null)
+            {
+                return _optional[0]?.ToString() ?? string.Empty;
+            }
+
+            return string.Empty;
         }
 
         public static implicit operator Optional<T>(T value)
@@ -79,8 +85,11 @@ namespace mRemoteNG.Tools
         /// values, the values are compared directly.
         /// </summary>
         /// <param name="other"></param>
-        public int CompareTo(Optional<T> other)
+        public int CompareTo(Optional<T>? other)
         {
+            if (other is null)
+                return 1; // Treat null as less than any non-null Optional
+
             bool otherHasAnything = other.Any();
             bool thisHasAnything = _optional.Length > 0;
 
@@ -100,21 +109,16 @@ namespace mRemoteNG.Tools
             throw new ArgumentException($"Cannot compare objects. Optional type {typeof(T).FullName} is not comparable to itself");
         }
 
-        #endregion
-
-        #region Override Equals and GetHashCode
-
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (ReferenceEquals(this, obj))
                 return true;
 
-            Optional<T> objAsOptional = obj as Optional<T>;
-            if (objAsOptional != null)
+            if (obj is Optional<T> objAsOptional)
                 return Equals(objAsOptional);
 
-            if (obj is T)
-                Equals((T)obj);
+            if (obj is T objAsT)
+                return Equals(objAsT);
 
             return false;
         }

mRemoteNG/Tools/PropertyGridCommandSite.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.ComponentModel;
 using System.ComponentModel.Design;
 using System.Reflection;
@@ -7,14 +7,9 @@ using System.Reflection;
 
 namespace mRemoteNG.Tools
 {
-    public class PropertyGridCommandSite : IMenuCommandService, ISite
+    public class PropertyGridCommandSite(object @object) : IMenuCommandService, ISite
     {
-        private readonly object TheObject;
-
-        public PropertyGridCommandSite(object @object)
-        {
-            TheObject = @object;
-        }
+        private readonly object TheObject = @object;
 
         public DesignerVerbCollection Verbs
         {
@@ -56,10 +51,9 @@ namespace mRemoteNG.Tools
             }
         }
 
-        private void VerbEventHandler(object sender, EventArgs e)
+        private void VerbEventHandler(object? sender, EventArgs e)
         {
-            DesignerVerb verb = sender as DesignerVerb;
-            if (verb == null)
+            if (sender is not DesignerVerb verb)
             {
                 return;
             }
@@ -100,16 +94,16 @@ namespace mRemoteNG.Tools
 
         public object GetService(Type serviceType)
         {
-            return serviceType == typeof(IMenuCommandService) ? this : null;
+            return serviceType == typeof(IMenuCommandService) ? this : null!;
         }
 
         public IComponent Component => throw new NotSupportedException();
 
-        public IContainer Container => null;
+        public IContainer Container => null!;
 
         public bool DesignMode => true;
 
-        public string Name
+        public string? Name
         {
             get => throw new NotSupportedException();
             set => throw new NotSupportedException();
@@ -151,13 +145,8 @@ namespace mRemoteNG.Tools
         }
     }
 
-    public class CommandAttribute : Attribute
+    public class CommandAttribute(bool isCommand = true) : Attribute
     {
-        public bool Command { get; set; }
-
-        public CommandAttribute(bool isCommand = true)
-        {
-            Command = isCommand;
-        }
+        public bool Command { get; set; } = isCommand;
     }
 }

mRemoteNG/Tools/ScanHost.cs

@@ -15,7 +15,7 @@ using mRemoteNG.Resources.Language;
 namespace mRemoteNG.Tools
 {
     [SupportedOSPlatform("windows")]
-    public class ScanHost
+    public class ScanHost(string host)
     {
         #region Properties
 
@@ -26,8 +26,8 @@ namespace mRemoteNG.Tools
         public static int RloginPort { get; set; } = (int)ProtocolRlogin.Defaults.Port;
         public static int RdpPort { get; set; } = (int)RdpProtocol.Defaults.Port;
         public static int VncPort { get; set; } = (int)ProtocolVNC.Defaults.Port;
-        public ArrayList OpenPorts { get; set; }
-        public ArrayList ClosedPorts { get; set; }
+        public ArrayList OpenPorts { get; set; } = [];
+        public ArrayList ClosedPorts { get; set; } = [];
         public bool Rdp { get; set; }
         public bool Vnc { get; set; }
         public bool Ssh { get; set; }
@@ -35,7 +35,7 @@ namespace mRemoteNG.Tools
         public bool Rlogin { get; set; }
         public bool Http { get; set; }
         public bool Https { get; set; }
-        public string HostIp { get; set; }
+        public string HostIp { get; set; } = host;
         public string HostName { get; set; } = "";
 
         public string HostNameWithoutDomain
@@ -52,16 +52,8 @@ namespace mRemoteNG.Tools
         }
 
         #endregion
-
         #region Methods
 
-        public ScanHost(string host)
-        {
-            HostIp = host;
-            OpenPorts = [];
-            ClosedPorts = [];
-        }
-
         public override string ToString()
         {
             try

mRemoteNG/Tools/Tools.LocalizedAttributes.cs

@@ -9,15 +9,10 @@ namespace mRemoteNG.Tools
     public class LocalizedAttributes
     {
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedCategoryAttribute : CategoryAttribute
+        public class LocalizedCategoryAttribute(string value, int Order = 1) : CategoryAttribute(value)
         {
             private const int MaxOrder = 10;
-            private int Order;
-
-            public LocalizedCategoryAttribute(string value, int Order = 1) : base(value)
-            {
-                this.Order = Order > MaxOrder ? MaxOrder : Order;
-            }
+            private int Order = Order > MaxOrder ? MaxOrder : Order;
 
             protected override string GetLocalizedString(string value)
             {
@@ -32,14 +27,9 @@ namespace mRemoteNG.Tools
         }
 
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedDisplayNameAttribute : DisplayNameAttribute
+        public class LocalizedDisplayNameAttribute(string value) : DisplayNameAttribute(value)
         {
-            private bool Localized;
-
-            public LocalizedDisplayNameAttribute(string value) : base(value)
-            {
-                Localized = false;
-            }
+            private bool Localized = false;
 
             public override string DisplayName
             {
@@ -57,14 +47,9 @@ namespace mRemoteNG.Tools
         }
 
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedDescriptionAttribute : DescriptionAttribute
+        public class LocalizedDescriptionAttribute(string value) : DescriptionAttribute(value)
         {
-            private bool Localized;
-
-            public LocalizedDescriptionAttribute(string value) : base(value)
-            {
-                Localized = false;
-            }
+            private bool Localized = false;
 
             public override string Description
             {
@@ -82,11 +67,8 @@ namespace mRemoteNG.Tools
         }
 
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedDefaultValueAttribute : DefaultValueAttribute
+        public class LocalizedDefaultValueAttribute(string name) : DefaultValueAttribute(Language.ResourceManager.GetString(name))
         {
-            public LocalizedDefaultValueAttribute(string name) : base(Language.ResourceManager.GetString(name))
-            {
-            }
 
             // This allows localized attributes in a derived class to override a matching
             // non-localized attribute inherited from its base class
@@ -96,14 +78,9 @@ namespace mRemoteNG.Tools
         #region Special localization - with String.Format
 
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedDisplayNameInheritAttribute : DisplayNameAttribute
+        public class LocalizedDisplayNameInheritAttribute(string value) : DisplayNameAttribute(value)
         {
-            private bool Localized;
-
-            public LocalizedDisplayNameInheritAttribute(string value) : base(value)
-            {
-                Localized = false;
-            }
+            private bool Localized = false;
 
             public override string DisplayName
             {
@@ -122,14 +99,9 @@ namespace mRemoteNG.Tools
         }
 
         [AttributeUsage(AttributeTargets.All, AllowMultiple = false, Inherited = true)]
-        public class LocalizedDescriptionInheritAttribute : DescriptionAttribute
+        public class LocalizedDescriptionInheritAttribute(string value) : DescriptionAttribute(value)
         {
-            private bool Localized;
-
-            public LocalizedDescriptionInheritAttribute(string value) : base(value)
-            {
-                Localized = false;
-            }
+            private bool Localized = false;
 
             public override string Description
             {

mRemoteNG/Tools/Tools.WindowPlacement.cs

@@ -7,15 +7,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Tools
 {
     [SupportedOSPlatform("windows")]
-    public class WindowPlacement
+    public class WindowPlacement(Form form)
     {
-        private Form _form;
-
-
-        public WindowPlacement(Form form)
-        {
-            _form = form;
-        }
+        private Form _form = form;
 
 
         #region Public Properties

mRemoteNG/Tree/ConnectionTreeModel.cs

@@ -19,22 +19,18 @@ namespace mRemoteNG.Tree
         {
             if (RootNodes.Contains(rootNode)) return;
             RootNodes.Add(rootNode);
-            rootNode.CollectionChanged += RaiseCollectionChangedEvent;
-            rootNode.PropertyChanged += RaisePropertyChangedEvent;
-            RaiseCollectionChangedEvent(this,
-                                        new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add,
-                                                                             rootNode));
+            rootNode.CollectionChanged += RaiseCollectionChangedEvent!;
+            rootNode.PropertyChanged += RaisePropertyChangedEvent!;
+            RaiseCollectionChangedEvent(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, rootNode));
         }
 
         public void RemoveRootNode(ContainerInfo rootNode)
         {
             if (!RootNodes.Contains(rootNode)) return;
-            rootNode.CollectionChanged -= RaiseCollectionChangedEvent;
-            rootNode.PropertyChanged -= RaisePropertyChangedEvent;
+            rootNode.CollectionChanged -= RaiseCollectionChangedEvent!;
+            rootNode.PropertyChanged -= RaisePropertyChangedEvent!;
             RootNodes.Remove(rootNode);
-            RaiseCollectionChangedEvent(this,
-                                        new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove,
-                                                                             rootNode));
+            RaiseCollectionChangedEvent(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, rootNode));
         }
 
         public IReadOnlyList<ConnectionInfo> GetRecursiveChildList()
@@ -76,16 +72,16 @@ namespace mRemoteNG.Tree
             connectionInfo?.RemoveParent();
         }
 
-        public event NotifyCollectionChangedEventHandler CollectionChanged;
+        public event NotifyCollectionChangedEventHandler? CollectionChanged;
 
-        private void RaiseCollectionChangedEvent(object sender, NotifyCollectionChangedEventArgs args)
+        public event PropertyChangedEventHandler? PropertyChanged;
+
+        private void RaiseCollectionChangedEvent(object? sender, NotifyCollectionChangedEventArgs args)
         {
             CollectionChanged?.Invoke(sender, args);
         }
 
-        public event PropertyChangedEventHandler PropertyChanged;
-
-        private void RaisePropertyChangedEvent(object sender, PropertyChangedEventArgs args)
+        private void RaisePropertyChangedEvent(object? sender, PropertyChangedEventArgs args)
         {
             PropertyChanged?.Invoke(sender, args);
         }

mRemoteNG/Tree/NodeSearcher.cs

@@ -7,19 +7,13 @@ using mRemoteNG.Connection;
 namespace mRemoteNG.Tree
 {
     [SupportedOSPlatform("windows")]
-    public class NodeSearcher
+    public class NodeSearcher(ConnectionTreeModel connectionTreeModel)
     {
-        private readonly ConnectionTreeModel _connectionTreeModel;
+        private readonly ConnectionTreeModel _connectionTreeModel = connectionTreeModel;
 
         private List<ConnectionInfo> Matches { get; set; }
         public ConnectionInfo CurrentMatch { get; private set; }
 
-
-        public NodeSearcher(ConnectionTreeModel connectionTreeModel)
-        {
-            _connectionTreeModel = connectionTreeModel;
-        }
-
         public IEnumerable<ConnectionInfo> SearchByName(string searchText)
         {
             ResetMatches();

mRemoteNG/Tree/Root/RootNodeInfo.cs

@@ -10,18 +10,11 @@ namespace mRemoteNG.Tree.Root
 {
     [SupportedOSPlatform("windows")]
     [DefaultProperty("Name")]
-    public class RootNodeInfo : ContainerInfo
+    public class RootNodeInfo(RootNodeType rootType, string uniqueId) : ContainerInfo(uniqueId)
     {
-        private string _name;
+        private string _name = Language.Connections;
         private string _customPassword = "";
 
-        public RootNodeInfo(RootNodeType rootType, string uniqueId)
-            : base(uniqueId)
-        {
-            _name = Language.Connections;
-            Type = rootType;
-        }
-
         public RootNodeInfo(RootNodeType rootType)
             : this(rootType, Guid.NewGuid().ToString())
         {
@@ -60,7 +53,7 @@ namespace mRemoteNG.Tree.Root
 
         [Browsable(false)] public string DefaultPassword { get; } = "mR3m"; //TODO move password away from code to settings
 
-        [Browsable(false)] public RootNodeType Type { get; set; }
+        [Browsable(false)] public RootNodeType Type { get; set; } = rootType;
 
         public override TreeNodeType GetTreeNodeType()
         {

mRemoteNG/Tree/SelectedConnectionDeletionConfirmer.cs

@@ -8,14 +8,9 @@ using System.Runtime.Versioning;
 namespace mRemoteNG.Tree
 {
     [SupportedOSPlatform("windows")]
-    public class SelectedConnectionDeletionConfirmer : IConfirm<ConnectionInfo>
+    public class SelectedConnectionDeletionConfirmer(Func<string, DialogResult> confirmationFunc) : IConfirm<ConnectionInfo>
     {
-        private readonly Func<string, DialogResult> _confirmationFunc;
-
-        public SelectedConnectionDeletionConfirmer(Func<string, DialogResult> confirmationFunc)
-        {
-            _confirmationFunc = confirmationFunc;
-        }
+        private readonly Func<string, DialogResult> _confirmationFunc = confirmationFunc;
 
         public bool Confirm(ConnectionInfo deletionTarget)
         {

mRemoteNG/UI/Controls/Adapters/CredentialRecordListAdaptor.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 using System.Drawing.Design;
 using System.Runtime.Versioning;
 using System.Windows.Forms.Design;
@@ -12,12 +13,12 @@ namespace mRemoteNG.UI.Controls.Adapters
     {
         private IWindowsFormsEditorService _editorService;
 
-        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext context)
+        public override UITypeEditorEditStyle GetEditStyle(ITypeDescriptorContext? context)
         {
             return UITypeEditorEditStyle.DropDown;
         }
 
-        public override object EditValue(ITypeDescriptorContext context, IServiceProvider provider, object value)
+        public override object? EditValue(ITypeDescriptorContext? context, IServiceProvider provider, object? value)
         {
             if (provider == null) return value;
             _editorService = provider.GetService(typeof(IWindowsFormsEditorService)) as IWindowsFormsEditorService;
@@ -30,7 +31,7 @@ namespace mRemoteNG.UI.Controls.Adapters
 
             _editorService.DropDownControl(listBox);
             if (listBox.SelectedItem == listBox.NoneSelection)
-                return null;
+                return null!;
             if (listBox.SelectedItem == listBox.AddNewSelection)
             {
                 //var newCred = new CredentialRecord();
@@ -41,7 +42,7 @@ namespace mRemoteNG.UI.Controls.Adapters
             return listBox.SelectedItem ?? value;
         }
 
-        private void ListBoxOnSelectedValueChanged(object sender, EventArgs eventArgs)
+        private void ListBoxOnSelectedValueChanged([NotNull] object? sender, EventArgs eventArgs)
         {
             _editorService.CloseDropDown();
         }

mRemoteNG/UI/Controls/FilteredPropertyGrid/ObjectWrapper.cs

@@ -15,7 +15,7 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// <param name="obj">A reference to the selected object that will linked to the parent PropertyGrid.</param>
         internal ObjectWrapper(object obj)
         {
-            SelectedObject = obj;
+            SelectedObject = obj ?? throw new ArgumentNullException(nameof(obj));
         }
 
         /// <summary>
@@ -26,11 +26,11 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// <summary>
         /// Get or set a reference to the collection of properties to show in the parent PropertyGrid
         /// </summary>
-        public List<PropertyDescriptor> PropertyDescriptors { get; set; } = [];
+        public List<PropertyDescriptor> PropertyDescriptors { get; set; } = new List<PropertyDescriptor>();
 
         #region ICustomTypeDescriptor Members
 
-        public PropertyDescriptorCollection GetProperties(Attribute[] attributes)
+        public PropertyDescriptorCollection GetProperties(Attribute[]? attributes)
         {
             return GetProperties();
         }
@@ -55,7 +55,7 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// <returns>String</returns>
         public string GetClassName()
         {
-            return TypeDescriptor.GetClassName(SelectedObject, true);
+            return TypeDescriptor.GetClassName(SelectedObject, true) ?? string.Empty;
         }
 
         /// <summary>
@@ -64,7 +64,7 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// <returns>String</returns>
         public string GetComponentName()
         {
-            return TypeDescriptor.GetComponentName(SelectedObject, true);
+            return TypeDescriptor.GetComponentName(SelectedObject, true) ?? string.Empty;
         }
 
         /// <summary>
@@ -80,8 +80,9 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// GetDefaultEvent
         /// </summary>
         /// <returns>EventDescriptor</returns>
-        public EventDescriptor GetDefaultEvent()
+        public EventDescriptor? GetDefaultEvent()
         {
+            // Explicitly mark the return type as nullable to handle the possibility of null.
             return TypeDescriptor.GetDefaultEvent(SelectedObject, true);
         }
 
@@ -89,7 +90,7 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// GetDefaultProperty
         /// </summary>
         /// <returns>PropertyDescriptor</returns>
-        public PropertyDescriptor GetDefaultProperty()
+        public PropertyDescriptor? GetDefaultProperty()
         {
             return TypeDescriptor.GetDefaultProperty(SelectedObject, true);
         }
@@ -99,12 +100,12 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
         /// </summary>
         /// <param name="editorBaseType">editorBaseType</param>
         /// <returns>object</returns>
-        public object GetEditor(Type editorBaseType)
+        public object? GetEditor(Type editorBaseType)
         {
             return TypeDescriptor.GetEditor(this, editorBaseType, true);
         }
 
-        public EventDescriptorCollection GetEvents(Attribute[] attributes)
+        public EventDescriptorCollection GetEvents(Attribute[]? attributes)
         {
             return TypeDescriptor.GetEvents(SelectedObject, attributes, true);
         }
@@ -114,7 +115,7 @@ namespace mRemoteNG.UI.Controls.FilteredPropertyGrid
             return TypeDescriptor.GetEvents(SelectedObject, true);
         }
 
-        public object GetPropertyOwner(PropertyDescriptor pd)
+        public object? GetPropertyOwner(PropertyDescriptor? pd)
         {
             return SelectedObject;
         }

mRemoteNG/UI/Controls/PageSequence/SequencedPageReplcementRequestArgs.cs

@@ -11,15 +11,9 @@ namespace mRemoteNG.UI.Controls.PageSequence
         NextPage
     }
 
-    public class SequencedPageReplcementRequestArgs
+    public class SequencedPageReplcementRequestArgs(SequencedControl newControl, RelativePagePosition pageToReplace)
     {
-        public SequencedControl NewControl { get; }
-        public RelativePagePosition PagePosition { get; }
-
-        public SequencedPageReplcementRequestArgs(SequencedControl newControl, RelativePagePosition pageToReplace)
-        {
-            NewControl = newControl ?? throw new ArgumentNullException(nameof(newControl));
-            PagePosition = pageToReplace;
-        }
+        public SequencedControl NewControl { get; } = newControl ?? throw new ArgumentNullException(nameof(newControl));
+        public RelativePagePosition PagePosition { get; } = pageToReplace;
     }
 }

mRemoteNG/UI/Controls/QuickConnectComboBox.cs

@@ -185,14 +185,9 @@ namespace mRemoteNG.UI.Controls
 
         #region Events
 
-        public class ConnectRequestedEventArgs : EventArgs
+        public class ConnectRequestedEventArgs(string connectionString) : EventArgs
         {
-            public ConnectRequestedEventArgs(string connectionString)
-            {
-                ConnectionString = connectionString;
-            }
-
-            public string ConnectionString { get; }
+            public string ConnectionString { get; } = connectionString;
         }
 
         public delegate void ConnectRequestedEventHandler(object sender, ConnectRequestedEventArgs e);
@@ -212,14 +207,9 @@ namespace mRemoteNG.UI.Controls
             ConnectRequestedEvent?.Invoke(this, new ConnectRequestedEventArgs(e.ConnectionString));
         }
 
-        public class ProtocolChangedEventArgs : EventArgs
+        public class ProtocolChangedEventArgs(ProtocolType protocol) : EventArgs
         {
-            public ProtocolChangedEventArgs(ProtocolType protocol)
-            {
-                Protocol = protocol;
-            }
-
-            public ProtocolType Protocol { get; }
+            public ProtocolType Protocol { get; } = protocol;
         }
 
         public delegate void ProtocolChangedEventHandler(object sender, ProtocolChangedEventArgs e);

mRemoteNG/UI/Controls/mrngIpTextBox.cs

@@ -32,7 +32,7 @@ namespace mRemoteNG.UI.Controls
         /* Sets and Gets the tooltiptext on toolTip1 */
         public string ToolTipText
         {
-            get => toolTip1.GetToolTip(Octet1);
+            get => toolTip1.GetToolTip(Octet1) ?? string.Empty;
             set
             {
                 toolTip1.SetToolTip(Octet1, value);
@@ -46,34 +46,48 @@ namespace mRemoteNG.UI.Controls
         }
 
         /* Set or Get the string that represents the value in the box */
-        public override string Text
+        public override string? Text
         {
-            get => Octet1.Text + @"." + Octet2.Text + @"." + Octet3.Text + @"." + Octet4.Text;
+            get => (Octet1.Text ?? string.Empty) + @"." + (Octet2.Text ?? string.Empty) + @"." + (Octet3.Text ?? string.Empty) + @"." + (Octet4.Text ?? string.Empty);
             set
             {
                 if (!string.IsNullOrEmpty(value))
                 {
                     string[] pieces = value.Split(@".".ToCharArray(), 4);
-                    Octet1.Text = pieces[0];
-                    Octet2.Text = pieces[1];
-                    Octet3.Text = pieces[2];
-                    Octet4.Text = pieces[3];
+                    Octet1.Text = pieces.Length > 0 ? pieces[0] : string.Empty;
+                    Octet2.Text = pieces.Length > 1 ? pieces[1] : string.Empty;
+                    Octet3.Text = pieces.Length > 2 ? pieces[2] : string.Empty;
+                    Octet4.Text = pieces.Length > 3 ? pieces[3] : string.Empty;
                 }
                 else
                 {
-                    Octet1.Text = "";
-                    Octet2.Text = "";
-                    Octet3.Text = "";
-                    Octet4.Text = "";
+                    Octet1.Text = string.Empty;
+                    Octet2.Text = string.Empty;
+                    Octet3.Text = string.Empty;
+                    Octet4.Text = string.Empty;
                 }
             }
         }
 
+        /* Fix for CS8618: Initialize all non-nullable fields in the constructor to ensure they are not null. */
+
         public MrngIpTextBox()
         {
             // This call is required by the Windows.Forms Form Designer.
             InitializeComponent();
             SetTabSTopProperties();
+
+            // Initialize non-nullable fields to avoid CS8618 warnings
+            panel1 = new Panel();
+            Octet1 = new MrngTextBox();
+            Octet2 = new MrngTextBox();
+            Octet3 = new MrngTextBox();
+            Octet4 = new MrngTextBox();
+            label1 = new MrngLabel();
+            label2 = new MrngLabel();
+            label3 = new MrngLabel();
+            toolTip1 = new ToolTip();
+            components = new System.ComponentModel.Container();
         }
 
         private void SetTabSTopProperties()
@@ -269,10 +283,11 @@ namespace mRemoteNG.UI.Controls
             }
         }
 
-        /* Performs KeyPress analysis and handling to ensure a valid ip octet is
-         * being entered in Box1.
+        /* Update the method signatures to include nullable reference type annotations
+         * to match the nullability of the target delegate 'KeyPressEventHandler'.
          */
-        private void Box1_KeyPress(object sender, KeyPressEventArgs e)
+
+        private void Box1_KeyPress(object? sender, KeyPressEventArgs e)
         {
             //Only Accept a '.', a numeral, or backspace
             if (e.KeyChar.ToString() == "." || char.IsDigit(e.KeyChar) || e.KeyChar == 8)
@@ -317,7 +332,7 @@ namespace mRemoteNG.UI.Controls
         /* Performs KeyPress analysis and handling to ensure a valid ip octet is
          * being entered in Box2.
          */
-        private void Box2_KeyPress(object sender, KeyPressEventArgs e)
+        private void Box2_KeyPress(object? sender, KeyPressEventArgs e)
         {
             //Similar to Box1_KeyPress but in special case for backspace moves cursor
             //to the previous box (Box1)
@@ -361,7 +376,7 @@ namespace mRemoteNG.UI.Controls
         /* Performs KeyPress analysis and handling to ensure a valid ip octet is
          * being entered in Box3.
          */
-        private void Box3_KeyPress(object sender, KeyPressEventArgs e)
+        private void Box3_KeyPress(object? sender, KeyPressEventArgs e)
         {
             //Identical to Box2_KeyPress except that previous box is Box2 and
             //next box is Box3
@@ -405,7 +420,7 @@ namespace mRemoteNG.UI.Controls
         /* Performs KeyPress analysis and handling to ensure a valid ip octet is
          * being entered in Box4.
          */
-        private void Box4_KeyPress(object sender, KeyPressEventArgs e)
+        private void Box4_KeyPress(object? sender, KeyPressEventArgs e)
         {
             //Similar to Box3 but ignores the '.' character and does not advance
             //to the next box.  Also Box3 is previous box for backspace case.
@@ -428,11 +443,11 @@ namespace mRemoteNG.UI.Controls
                 e.Handled = true;
         }
 
-        // Selects All text in a box for overwriting upon entering the box
-        private void Box_Enter(object sender, EventArgs e)
+        // Update the method signature to include nullable reference type annotations
+        private void Box_Enter(object? sender, EventArgs e)
         {
-            TextBox tb = (TextBox)sender;
-            tb.SelectAll();
+            TextBox? tb = sender as TextBox;
+            tb?.SelectAll();
         }
     }
 }

mRemoteNG/UI/Controls/mrngPictureBox.Designer.cs

@@ -26,10 +26,7 @@
         /// Required method for Designer support - do not modify
         /// the contents of this method with the code editor.
         /// </summary>
-        private void InitializeComponent()
-        {
-            components = new System.ComponentModel.Container();
-        }
+        private void InitializeComponent() => components = new System.ComponentModel.Container();
 
         #endregion
     }

mRemoteNG/UI/DisplayProperties.cs

@@ -8,10 +8,15 @@ using mRemoteNG.UI.GraphicsUtilities;
 
 namespace mRemoteNG.UI
 {
+    /// <summary>
+    /// Creates a new <see cref="DisplayProperties"/> instance with the given
+    /// <see cref="IGraphicsProvider"/>.
+    /// </summary>
+    /// <param name="graphicsProvider"></param>
     [SupportedOSPlatform("windows")]
-    public class DisplayProperties
+    public class DisplayProperties(IGraphicsProvider graphicsProvider)
     {
-        private readonly IGraphicsProvider _graphicsProvider;
+        private readonly IGraphicsProvider _graphicsProvider = graphicsProvider.ThrowIfNull(nameof(graphicsProvider));
 
         public SizeF ResolutionScalingFactor => _graphicsProvider.GetResolutionScalingFactor();
 
@@ -24,16 +29,6 @@ namespace mRemoteNG.UI
         {
         }
 
-        /// <summary>
-        /// Creates a new <see cref="DisplayProperties"/> instance with the given
-        /// <see cref="IGraphicsProvider"/>.
-        /// </summary>
-        /// <param name="graphicsProvider"></param>
-        public DisplayProperties(IGraphicsProvider graphicsProvider)
-        {
-            _graphicsProvider = graphicsProvider.ThrowIfNull(nameof(graphicsProvider));
-        }
-
         /// <summary>
         /// Scale the given nominal width value by the <see cref="ResolutionScalingFactor"/>
         /// </summary>

mRemoteNG/UI/Forms/FrmExport.cs

@@ -272,21 +272,15 @@ namespace mRemoteNG.UI.Forms
         #region Private Classes
 
         [ImmutableObject(true)]
-        private class ExportFormat
+        private class ExportFormat(SaveFormat format)
         {
             #region Public Properties
 
-            public SaveFormat Format { get; }
+            public SaveFormat Format { get; } = format;
 
             #endregion
-
             #region Constructors
 
-            public ExportFormat(SaveFormat format)
-            {
-                Format = format;
-            }
-
             #endregion
 
             #region Public Methods

mRemoteNG/UI/Forms/OptionsPages/OptionsPage.cs

@@ -94,15 +94,9 @@ namespace mRemoteNG.UI.Forms.OptionsPages
             }
         }
     }
-    internal class DropdownList
+    internal class DropdownList(int argIndex, string argDisplay)
     {
-        public int Index { get; set; }
-        public string DisplayString { get; set; }
-
-        public DropdownList(int argIndex, string argDisplay)
-        {
-            Index = argIndex;
-            DisplayString = argDisplay;
-        }
+        public int Index { get; set; } = argIndex;
+        public string DisplayString { get; set; } = argDisplay;
     }
 }

mRemoteNG/UI/Forms/OptionsPages/SqlServerPage.Designer.cs

@@ -9,10 +9,7 @@ namespace mRemoteNG.UI.Forms.OptionsPages
 
         //UserControl overrides dispose to clean up the component list.
         [System.Diagnostics.DebuggerNonUserCode()]
-        protected override void Dispose(bool disposing)
-        {
-            base.Dispose(disposing);
-        }
+        protected override void Dispose(bool disposing) => base.Dispose(disposing);
 
         //NOTE: The following procedure is required by the Windows Form Designer
         //It can be modified using the Windows Form Designer.