How can I change the colour of selected text in a WPF ComboBox?

In my application, I have defined the following style for TextBlocks.

<Style TargetType="{x:Type TextBlock}">
    <Setter Property="FontFamily" Value="Arial"/>
    <Setter Property="FontSize" Value="11"/>
    <Setter Property="Foreground" Value="{StaticResource TextBrush}"/>
    <Setter Property="Opacity" Value="1.0"/>
    <Style.Triggers>
        <Trigger Property="IsEnabled" Value="false">
            <Setter Property="Opacity" Value="0.40"/>
        </Trigger>
    </Style.Triggers>
</Style>

The style is intentionally defined at the highest level of my application so that it applies 开发者_开发知识库to all TextBlocks by default.

The problem is that this style breaks the behaviour of TextBlocks in ComboBoxes. Normally, the selected item in a ComboBox has its Foreground colour change to white. With this style applied however, the foreground colour of the text does not change.

How can I trigger the text to change colour when the TextBlock in a ComboBox is highlighted?

If you just want to change the texblock foreground for selected item(say Red), just add this to your style resources:

<Style.Resources>
    <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Red"/>
</Style.Resources>

I resolved this issue by moving the styles out of app.xaml and into a separate resource dictionary that I include as needed in my application Window & Pages.

This stops the TextBlock style from affecting the colour of the text in the ComboBox. Finally, to achieve the text colour I wanted on all items I overrode the following default system colours with my own.

<SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}"
                 Color="{StaticResource TextColor}"/>

<SolidColorBrush x:Key="{x:Static SystemColors.WindowTextBrushKey}"
                 Color="{StaticResource TextColor}"/>

You can add second style based on your first and reset background property.

<Style TargetType="{x:Type TextBlock}">
    <Setter Property="Foreground" Value="{StaticResource TextBrush}"/>
</Style>

<Style TargetType="{x:Type TextBlock}" BasedOn="{StaticResource {x:Type TextBlock}}" x:Key="ResetBG">
    <Setter Property="Foreground" Value="{Binding Control.Background}"/>
</Style>

<TextBlock Text="Red"/>
<TextBlock Text="Default" Style="{StaticResource ResourceKey=ResetBG}"/>