Style DataTrigger with reference to Type of parent control

Question

On my Window there are several GroupBox Controls, each containing a Grid Control. To those Grids I want to asign a Style. But only to those Grids that are directly in a GroupBox, all other Grids should not be affected.

I have tried the following, which does not work as GetType() is no property.

<Style TargetType="Grid">
    <Style.Triggers>
        <DataTrigger Binding="{Binding RelativeSource={RelativeSource Mode=Self}, Path=Parent.GetType()}" Value="{x:Type GroupBox}">
           <!-- <Setter Property="..." Value="..."/> -->
        </DataTrigger>
    </Style.Triggers>
</Style>

I have found a workaround, but it's not really a beautiful solution, as I have to modify the GroupBoxes:

<Style TargetType="GroupBox">
    <Setter Property="Tag" Value="blub"/>
 </Style>
<Style TargetType="Grid">
    <Style.Triggers>
        <DataTrigger Binding="{Binding Path=Parent.Tag, RelativeSource={RelativeSource Mode=Self}}" Value="blub">
           <!-- <Setter Property="..." Value="..."/> -->
        </DataTrigger>
    </Style.Triggers>
</Style>

Obviously I could set the style for each Grid manually, but I'm trying to avoid that, as there are quite a lot of them. I hope you can find a way to make the first example work.

Answer 1

<DataTrigger Binding="{Binding Path=Parent.Tag, RelativeSource={RelativeSource Mode=Self}}" Value="blub">

This code would not work, because type of Mode is actually BindingMode which is an Enumeration, and none of it's member is Self. So this assignment Mode=Self is wrong in your code. To know the possible values of Mode, click this.

The correct way to write this is,

<DataTrigger Binding="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type GroupBox}}, Path=Tag}" Value="blub">

And of course, for this to work, you've to keep that Style for GroupBox which you've already written.