DelegateCommand

DelegateCommand.cs

	public class DelegateCommand<T> : ICommand
	{
		readonly Func<T, bool> canExecute = _ => true;
		readonly Action<T> executeAction;

		bool canExecuteCache;

		public DelegateCommand(Action<T> executeAction, Func<T, bool> canExecute)
		{
			this.executeAction = executeAction;
			this.canExecute = canExecute;
		}

		public DelegateCommand(Action<T> executeAction)
		{
			this.executeAction = executeAction;
		}

		#region ICommand Members

		public bool CanExecute(object parameter)
		{
			if (canExecute != null)
			{
				bool temp = canExecute((T)parameter);
				if (canExecuteCache != temp)
				{
					canExecuteCache = temp;
					if (CanExecuteChanged != null)
					{
						CanExecuteChanged(this, new EventArgs());
					}
				}
				return canExecuteCache;
			}
			return true;
		}

		public void Execute(object parameter)
		{
			executeAction((T)parameter);
		}

		public event EventHandler CanExecuteChanged;

		#endregion

	}

	//Non generic
	public class DelegateCommand : DelegateCommand<object>
	{
		public DelegateCommand(Action<object> executeAction, Func<object, bool> canExecute)
			: base(executeAction, canExecute)
		{
		}

		public DelegateCommand(Action<object> executeAction)
			: base(executeAction)
		{
		}
	}

	public class AsyncDelegateCommand : DelegateCommand<object>
	{
		public AsyncDelegateCommand(Func<object, Task> executeAction, Func<object, bool> canExecute)
			: base(async o => await executeAction(o), canExecute)
		{
		}

		public AsyncDelegateCommand(Func<object, Task> executeAction)
			: base(async o => await executeAction(o))
		{
		}
	}