TriggerAction後のCanCloseの変化に対応したLivetのWindowCloseCancelBehavior

WindowClosingCancelBehavior.cs

using System.ComponentModel;
using Livet.Behaviors;

namespace Sample.Behaviors
{
	sealed class WindowClosingCancelBehavior : WindowCloseCancelBehavior
	{
		CancelEventArgs cancel;
		readonly DependencyPropertyDescriptor descriptor;

		public WindowClosingCancelBehavior()
		{
			descriptor = DependencyPropertyDescriptor.FromProperty(CanCloseProperty, typeof(WindowCloseCancelBehavior));
		}

		protected override void OnAttached()
		{
			AssociatedObject.Closing += (sender, e) =>
			{
				if (cancel == null)
					descriptor.AddValueChanged(this, (self, _) => cancel.Cancel = !CanClose);
				cancel = e;
			};
			base.OnAttached();
		}
	}
}