Hua.Todo/TodoList/Services/SqliteDataService.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Threading.Tasks;
using SQLite;
using TodoList.Models;

namespace TodoList.Services
{
    public class SqliteDataService : IDataService
    {
        private readonly SQLiteAsyncConnection _database;

        public SqliteDataService()
        {
            var appData = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
            var folder = Path.Combine(appData, "TodoListApp");
            Directory.CreateDirectory(folder);
            var databasePath = Path.Combine(folder, "TodoList.sqlite");

            _database = new SQLiteAsyncConnection(databasePath);
            _database.CreateTableAsync<TodoItem>().Wait();
        }

        public async Task<List<TodoItem>> LoadTasksAsync()
        {
            return await _database.Table<TodoItem>().ToListAsync();
        }

        public async Task SaveTaskAsync(TodoItem task)
        {
            await _database.InsertOrReplaceAsync(task);
        }

        public async Task SaveAllAsync(List<TodoItem> tasks)
        {
            await _database.RunInTransactionAsync(tran =>
            {
                foreach (var task in tasks)
                {
                    tran.InsertOrReplace(task);
                }
            });
        }

        public async Task DeleteTaskAsync(string id)
        {
            await _database.DeleteAsync<TodoItem>(id);
        }
    }
}