Question

I have some StackPanels I wish to have the same Width. However this should not affect all StackPanels and I do not want to subclass just for this. I know that the following is possible:

<Style BasedOn="{StaticResource {x:Type TextBlock}}"
    TargetType="TextBlock"
    x:Key="TitleText">
        <Setter Property="FontSize" Value="26"/>
</Style>

...

<TextBlock Style="{StaticResource TitleText}"> 
    Some Text 
</TextBlock>

But is there a way to keep the TextBlock ignorant of its Style (like it is when the
HTML is separate from the CSS rule that applies to the element)?

I would just like to give all the relevant StackPanels the same class id, and then apply
the style to the class id.

Answer 1

Unfortunately, this is not possible in WPF. The closest you can come to this is what you’ve demonstrated in your example.

However, if you want to apply a style to all StackPanels in the same root container, you can specify the Style as a resource of the root container, leaving the x:Key attribute out. As an example:

<Grid x:Name="LayoutRoot">
    <Grid x:Name="StackPanelsRoot">
        <Grid.Resources>
            <Style TargetType="StackPanel">
                ...
            </Style>
        </Grid.Resources>
        <StackPanel x:Name="SP1" ... />
        <StackPanel x:Name="SP2" ... />
        ...
    </Grid>
    <StackPanel x:Name="SP3" ... />
    ...
</Grid>

Here, the Style will be applied to SP1 and SP2, but not to SP3