TextBlock.Foreground defined in a style is ignored

I have defined a named Style for TextBlock setting font size and foreground color and several textblock instances using this style within user controls. While the FontSize setting of the style is always applied, the Foreground setting is only applied if the FontWeight property of the text block is explicitly set.

Here's the XAML:

Note that Style and TextBlock are actually not in the same file, but in the same assembly. The text block is rendered in size 22 but with black foreground.

<Style x:Key="StandardTextBlockStyle" TargetType="TextBlock">
    <Setter Property="FontSize" Value="22" />
    <Setter Property="Foreground" Value="#FF999999"/>
</Style>

<TextBlock Text="Test." 
           Style="{DynamicResource StandardTextBlockStyle}"
           VerticalAlignment="Top"
           Margin="0,5,3,0" 
           Grid.Column="0" 
           Grid.Row="0" />

If I set the FontWeight property of the text block explicitly (no matter to which value), the foreground setting of the style is applied:

<TextBlock Text="Test." 
           Style="{DynamicResource StandardTextBlockStyle}"
           VerticalAlignment="Top"
           FontWeight="Regular"
           Margin="0,5,3,0" 
           Grid.Column="0" 
           Grid.Row="0" />

The main method of my program basically looks like this:

[STAThread]
public static void Main()
{
    Application app = new Application();
    Window w = new TestWindow();

    var resource = (ResourceDictionary)Application.LoadComponent(new Uri("/TestProg.UIL;component/SkinBright.xaml", UriKind.RelativeOrAbsolute));
    app.Resources.MergedDictionaries.Add(resource);

    app.Run(w);
}

开发者_如何学编程SkinBright.xaml is the resource dictionary which contains the StandardTextBlockStyle mentioned above.

Any ideas why this happens and how to avoid the need to set the font weight on all text blocks?

i tried your code and it works (EDIT .NET4.0)

<Grid>
    <Grid.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="Dictionary1.xaml"/>
            </ResourceDictionary.MergedDictionaries>
        </ResourceDictionary>
    </Grid.Resources>
    <TextBlock Text="Lorem Ipsum"
               Style="{DynamicResource StandardTextBlockStyle}"/>
</Grid>

Try:

<Style x:Key="StandardTextBlockStyle" TargetType="TextBlock" BasedOn="{StaticResource {x:Type TextBlock}}">