Styling a groupbox in WPF

Question

How can I set the opacity of the background for a groupbox etc.

The code beneath doesn't compile:

<Style TargetType="GroupBox">
    <Setter Property="Background">
        <Setter.Value>
            <SolidColorBrush Opacity="0.5">White</SolidColorBrush>
        </Setter.Value>
    </Setter>
</Style>

Answer 1

Your code isn't compiling not because of the opacity, but because of the value "White". You have to apply this to the brush Color.

You can use:

<SolidColorBrush Opacity="0.5" Color="White" />

or

<SolidColorBrush Opacity="0.5">
    <SolidColorBrush.Color>White</SolidColorBrush.Color>
</SolidColorBrush>