在文本上产生与Windows标题相同的效果

Question

I create a transparency window with different textblock but my text isn't always readable because it's depends of colors user's window.

So I want apply the same effect on a text like the effect of my title window, It's like a white shadow.

Thank you

Answer 1

The best way to do this would be to use a shader effect. I tried to do this with the built in Blur effect but it seems they don't blend with Alpha.

Below is an example of how I would start and doesn't represent an end product. HLSL border effect based off of Emboss effect.

View the full image for a better understanding. This effect only adds like 2 px border so the scaling makes it look even worse.

I'm pretty bad at writing HLSL the code on the right is just copy-pasted from http://brooknovak.wordpress.com/2008/09/16/simple-image-filters-written-as-hlsl-pixel-shaders/ with modification.

I'm sure someone who knew HLSL / GLSL could write a blur effect that works correctly. Note that this effect works across a full image and thus needs to know the image size. You should put them in a constant buffer and use them instead of the hardcoded 500.0 for width and height. They need to be the width/height of the rendered object. In my example it is actually the entire left half side of the window not just the size of the text because my XAML looks like this...

<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"
        Loaded="Window_Loaded" Background="Transparent">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="264*" />
            <ColumnDefinition Width="239*" />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="218*" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <TextBlock Text="The quick brown fox jumped over the lazy dog." Foreground="White" Background="Transparent" Grid.RowSpan="3" x:Name="PART_TextBlock"/>
        <TextBox x:Name="PART_TextBox" Grid.Column="1" HorizontalScrollBarVisibility="Disabled" VerticalScrollBarVisibility="Visible" AcceptsReturn="True" AcceptsTab="True" />
        <TextBlock x:Name="PART_Error" Grid.Column="1" Grid.Row="1"/>
        <Button Content="Compile &amp; Apply" Grid.Column="1" Grid.Row="2" Padding="4,1" Margin="4" HorizontalAlignment="Center" Click="Button_Click" />
    </Grid>
</Window>