How to FadeOut Window form on Close Button In WPF C# - wpf

Question

int FadeOut;
for (FadeOut = 90; FadeOut >= 10; FadeOut += -10)
{
this.Opacity = FadeOut / 100;
this.refresh();
System.Threading.Thread.Sleep(50);
}
I did something like this but not working
// this.refresh(); is not working

Answer 1

Here's discussed the same problem.
Also you can use triggers: Event triggers or data triggers to initiate animation, and Completed event of animation to set callback on animation end.
Here's data trigger (you should have FadeOut property in your data context)
<Window.Resources>
<Storyboard x:Key="FadeOut">
<DoubleAnimation From="0" To="1" Storyboard.TargetProperty="(UIElement.Opacity)" Duration="0:0:1.5"/>
</Storyboard>
</Window.Resources>
<Window.Style>
<Style>
<Style.Triggers>
<DataTrigger Binding="{Binding Path=FadeOut}" Value="True">
<DataTrigger.EnterActions>
<BeginStoryboard Storyboard="{StaticResource FadeOut}"/>
</DataTrigger.EnterActions>
</DataTrigger>
</Style.Triggers>
</Style>
</Window.Style>

Answer 2

I did something like this, and you can work on it. Unfortunately you have to implement your own Window title bar :
<Window x:Class="WpfApplication2.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
Name="myWindow" WindowStyle="None" AllowsTransparency="True"
>
<Window.Resources>
</Window.Resources>
<Grid>
<Button Margin="337,0,0,155">
<Button.Triggers>
<EventTrigger RoutedEvent="Button.Click">
<BeginStoryboard >
<Storyboard Duration="0:0:5">
<DoubleAnimation Storyboard.TargetName="myWindow" Storyboard.TargetProperty="Opacity" From="1" To="0"></DoubleAnimation>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Button.Triggers>
</Button>
</Grid>
</Window>