Setter precedence overriding in WPF?

Look at the line "THIS LINE ####" in following example.

<ListBox Grid.Row="0" x:Name="listBoxServers">
<ListBoxItem HorizontalContentAlignment="Stretch">
    <StackPanel>
        <TextBlock><Run Text="My computer"/></TextBlock>
        <TextBlock Foreground="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}">
            <TextBlock.Style>
                <Style>
                    <Style.Triggers>
                        <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}}}" Value="True">
                            <Setter Property="TextBlock.Foreground" Value="White" />开发者_JS百科 <!-- THIS LINE #### How can I get this work? -->
                            <Setter Property="TextBlock.Background" Value="Blue" /> <!-- This line here for debugging purposes (to show that these really are called) -->
                        </DataTrigger>
                    </Style.Triggers>
                </Style>
            </TextBlock.Style>
            <Run Text="localhost"/>
        </TextBlock>
    </StackPanel>
</ListBoxItem>
</ListBox>

How can I get the following trigger to override the value?

(Btw, example above is just compressed. (In real application the the Style is in its own resource.))

This post might explain why the trigger doesn't fire when you have assigned a local value to the property.

You should be able to do this with two data triggers, one for true, and one for false.

    <TextBlock>
        <TextBlock.Style>
            <Style>
                <Style.Triggers>
                    <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}}}" Value="True">
                        <Setter Property="TextBlock.Foreground" Value="White" />
                        <Setter Property="TextBlock.Background" Value="Blue" />
                    </DataTrigger>
                    <DataTrigger Binding="{Binding IsSelected, RelativeSource={RelativeSource AncestorType={x:Type ListBoxItem}}}" Value="False">
                        <Setter Property="TextBlock.Foreground" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}" />
                    </DataTrigger>
                </Style.Triggers>
            </Style>
        </TextBlock.Style>
        <Run Text="localhost"/>
    </TextBlock>