GroupBox.Header not working

Question

I am trying to add an image to my GroupBox Header like so:

<GroupBox>
    <GroupBox.Header>
        <StackPanel Orientation="Horizontal">
            <Label Content="Test Box" />
            <Image Source="MyImage.jpg" />                   
        </StackPanel>
    </GroupBox.Header>
    .....
    <!-- All my other code which I know works correctly -->
    .....
<GroupBox>

However, what shows up for my GroupBox Header is:

I see this method of modifying the GroupBox Header all over the web when I search on how to do this but I cannot get it to work. I even tried removing the Image in case that was causing an issue and it still give the same result.

What am I doing wrong here?

Answer 1

After reading Ganesh's post, I did a search for a GroupBox style and found that there was one in my project that I was unaware of. The GroupBox style was defined as follows:

<!-- GroupBox & GroupBox.Header Style -->
<Style x:Key="GroupBoxStyle" TargetType="{x:Type GroupBox}">
    <Setter Property="Margin" Value="5" />
    <Setter Property="Padding" Value="5" />

    <Setter Property="HeaderTemplate">
        <Setter.Value>
            <DataTemplate>
                <TextBlock Text="{Binding}" FontWeight="Bold"/>
            </DataTemplate>
        </Setter.Value>
    </Setter>
</Style>

<Style TargetType="{x:Type GroupBox}" 
       BasedOn="{StaticResource GroupBoxStyle}" />

By changing my code to the following I was able to override the default GroupBox style:

    <GroupBox>
        <GroupBox.HeaderTemplate>
            <DataTemplate>
                <StackPanel Orientation="Horizontal">
                    <Label Content="Julius Caesar"/>
                    <Image Source="MyImage.jpg" /> 
                </StackPanel>
            </DataTemplate>
        </GroupBox.HeaderTemplate>
        ......