wpf - Darken the full screen when open popup

Question

I have a window with a button. When you click the button popup appears. How can I darken the full screen when open popup?

Answer 1

You should write your own shader in order to darken, lighten, engraying, moting blurring and doing other cool graphics stuff.

Of course, if you don't want it to do in a right way, you could just create an Rectangle with IsHitTestVisible = false property and black color and some 0.5f opacity all over your form, but...

Answer 2

This is called Adorner what you are looking for. Link here also might be of your interest.

Answer 3

One easy way to do this is to create a new UserControl like this:

<UserControl ...
<Grid Background="#AA000000"> <!-- control the overlay color here -->
        <Border Background="White" BorderBrush="Black" BorderThickness="1" HorizontalAlignment="Center" VerticalAlignment="Center" Padding="10">
            <TextBlock Text="content"/>
        </Border>
</Grid>
</UserControl>

Than just add it to the top grid of your window.