Make backgroud blur when a dialogbox appear

Question

I want background to be blur whenever a messagebox (or any dialogbox) appear and disappear as soon as main window is returned. How can I do this?

Answer 1

Display the content of the messagebox with Popup when you open it, it automatically blackout the background area, till you close the popup....

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Do vote the answer and propose the answer

Answer 2

Use a Blur effect on the window, perhaps create an animation that changes the Blurs Radius value

<Window
	xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
	xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	xmlns:System="clr-namespace:System;assembly=mscorlib"
	x:Class="MainWindow"
	x:Name="Window"
	Title="MainWindow"
	Width="640" Height="480">
	<Window.Resources>
		<Storyboard x:Key="BlurWindow">
			<DoubleAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Effect).(BlurEffect.Radius)" Storyboard.TargetName="Window">
				<EasingDoubleKeyFrame KeyTime="0" Value="0"/>
				<EasingDoubleKeyFrame KeyTime="0:0:0.5" Value="5"/>
			</DoubleAnimationUsingKeyFrames>
		</Storyboard>
	</Window.Resources>
	<Window.Triggers>
		<EventTrigger RoutedEvent="ButtonBase.Click" SourceName="button">
			<BeginStoryboard Storyboard="{StaticResource BlurWindow}"/>
		</EventTrigger>
	</Window.Triggers>
    <Window.Effect>
        <BlurEffect Radius="0"/>
    </Window.Effect>
    <Grid x:Name="LayoutRoot">
		<Grid.ColumnDefinitions>
			<ColumnDefinition Width="0.24*"/>
			<ColumnDefinition Width="0.393*"/>
			<ColumnDefinition Width="0.367*"/>
		</Grid.ColumnDefinitions>
		<Button x:Name="button" Content="Button" Width="75" HorizontalAlignment="Center" VerticalAlignment="Center"/>
		<TextBlock HorizontalAlignment="Center" TextWrapping="Wrap" VerticalAlignment="Center" Grid.Column="1"><Run Text="TextBlock"/></TextBlock>
		<ListBox Height="100" VerticalAlignment="Center" Margin="0,0,50,0" Grid.Column="2" HorizontalAlignment="Center">
			<ListBoxItem Content="One"/>
			<ListBoxItem Content="Two"/>
			<ListBoxItem Content="Three"/>
		</ListBox>
	</Grid>
</Window>