Fading out a wpf window on close

Question

I want to fade a window in/out in my application.
Fading in occurs on Window.Loaded and I wanted to fade out on close (Window.Closed or

Answer 1

This is even simpler and shorter. Add a behavior as follows:

public class WindowClosingBehavior : Behavior
    {
        protected override void OnAttached()
        {
            AssociatedObject.Closing += AssociatedObject_Closing;
        }

        private void AssociatedObject_Closing(object sender, System.ComponentModel.CancelEventArgs e)
        {
            Window window = sender as Window;
            window.Closing -= AssociatedObject_Closing;
            e.Cancel = true;
            var anim = new DoubleAnimation(0, (Duration)TimeSpan.FromSeconds(0.5));
            anim.Completed += (s, _) => window.Close();
            window.BeginAnimation(UIElement.OpacityProperty, anim);
        }
        protected override void OnDetaching()
        {
            AssociatedObject.Closing -= AssociatedObject_Closing;
        }
    }

Then in your window add a reference :

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:wt="clr-namespace:Desktop.Themes.WindowTask;assembly=Desktop.Themes"

Insert the behavior: