Hello,

I've applied the WMP11 style to my grid and have added a number of styles. For example, a different mouse over brush and alternating row brushes

 <Style TargetType="{x:Type DataGrid:DataRow}">
   
    <Setter Property="Background" Value="{DynamicResource DefaultRowBackgroundBrush}" />
    <Setter Property="Foreground" Value="White"/>
    <Style.Triggers>
      <DataTrigger Binding="{Binding Path=(DataGrid:DataGridVirtualizingPanel.ItemIndex), Converter={StaticResource rowIndexConverter}, RelativeSource={RelativeSource Self}}"
        Value="True">
        <Setter Property="Background" Value="{DynamicResource AlternateRowBackgroundBrush}" />
      </DataTrigger>
      <Trigger Property="IsMouseOver" Value="True">
        <Setter Property="Background" Value="{DynamicResource MouseOverRowBackgroundBrush}" />
      </Trigger>
    </Style.Triggers>
  </Style>

 What I'd like to do now is customise the way the ColumnHeaders are rendered by taking away the curved rectangle when it is moused over. I have found the parts of the theme where this effect is created:

<ControlTemplate x:Key="tableViewColumnManagerCellTemplate" TargetType="{x:Type ColumnManagerCell}">

...

<Grid Name="mgrCellmainGrid" Height="33" Margin="0,4,0,0">
            <Grid.RowDefinitions>
                <RowDefinition Height="3*" />
                <RowDefinition Height="4*" />
            </Grid.RowDefinitions>
            <Border Name="mgrCellborderBack" BorderThickness="1" CornerRadius="5,5,0,0" RowSpan="2" />
            <Border Name="mgrCellborderBackHotBlue" BorderThickness="1" CornerRadius="5,5,0,0" Opacity="0" RowSpan="2" Background="{StaticResource rowSelectorBackgroundBrush}" />
            <Border Name="mgrCellborderTopGradient" CornerRadius="5,5,0,0" Margin="1" Row="0" />
            <Border Name="mgrCellborder3" BorderBrush="#FFFFFF" BorderThickness="1" CornerRadius="5,5,0,0" Opacity="0" Margin="3,3,3,1" RowSpan="2" />
            <Border Name="mgrCellborder2" BorderBrush="#000000" BorderThickness="1" CornerRadius="5,5,0,0" Opacity="0" Margin="2,2,2,0" RowSpan="2" />
            <Border Name="mgrCellborder1" BorderBrush="#FFFFFF" BorderThickness="1" CornerRadius="5,5,0,0" Opacity="0" Margin="1,1,1,0" RowSpan="2" />

...

What I can't figure out is how to target the elements in there, say, to make them invisible or to recreate my own. Is it possible to target named controls rather than just a type?

e.g.

<Style TargetType="{x:Type Grid x:Name mgrCellBorder1}" >

  <Setter Property="Visibility" Value="Collapsed />

</Style>

How do you "get inside" a ControlTemplate definition like that for ColumnManagerCell to change its appearance?