Style.Trigger and CustomControl problem

Question

Hi all,

I am really getting mad since several hours... I am trying to do a custom ListView control, almost everything is fine except for the GridViewColumnHeader bar color.

I have an ExListView control overriding ListView and a ExGridViewColumnHeader overriding GridViewColumnHeader. My problem is that only the column header are styled, not the rest of my column header bar. I have seen that to style this one I have to when the Role property is "Padding" but it doesn't do anything. Are style triggers not working when we do a custom control ?

Here is my ExGridViewColumnHeader XAML :

<Style TargetType="{x:Type local:ExGridViewColumnHeader}">

    <Setter Property="HorizontalContentAlignment" Value="Center"/>
    <Setter Property="VerticalContentAlignment" Value="Center"/>
    <Setter Property="Foreground" Value="White"/>

    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate TargetType="{x:Type local:ExGridViewColumnHeader}">

                <Grid>

                    <Border x:Name="HeaderBorder" Style="{DynamicResource SLV_HeaderBorderStyle}">

                        <ContentPresenter Name="HeaderContent"
                            Margin="0,0,0,1"
                            VerticalAlignment="{TemplateBinding VerticalContentAlignment}"
                            HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
                            RecognizesAccessKey="True"
                            SnapsToDevicePixels="True"
                            Opacity="0.9"/>

                    </Border>

                    <Thumb x:Name="PART_HeaderGripper" HorizontalAlignment="Right" Margin="0,0,-9,0" Style="{StaticResource GridViewColumnHeaderGripper}"/>

                </Grid>

                <ControlTemplate.Triggers>
                    <Trigger Property="IsMouseOver" Value="true">
                        <Setter TargetName="HeaderBorder" Property="Style" Value="{DynamicResource SLV_HeaderBorderHoverStyle}"/>
                    </Trigger>

                    <Trigger Property="IsPressed" Value="true">
                        <Setter TargetName="HeaderBorder" Property="Style" Value="{DynamicResource SLV_HeaderBorderPressedStyle}"/>
                        <Setter TargetName="HeaderContent" Property="Margin" Value="1,1,0,0"/>
                    </Trigger>

                </ControlTemplate.Triggers>
            </ControlTemplate>
        </Setter.Value>
    </Setter>

    <Style.Triggers>
        <Trigger Property="Role" Value="Padding">
            <Setter Property="Template">
                <Setter.Value>

                    <ControlTemplate TargetType="{x:Type local:ExGridViewColumnHeader}">
                        <Border Name="HeaderBorder" Background="Red" />
                    </ControlTemplate>

                </Setter.Value>
            </Setter>
        </Trigger>
    </Style.Triggers>
</Style>