DisplayMemberPath for WPF CustumControl

Hi, 

I'm writing CustumControl inherited from UserControl.

So, I have a ListBox that contain Image as ItemTemplate. I want to do a DisplayMemberPath property same as the ListBox or ComboBox.

<UserControl ....>
<ListBox ItemsSource="{Binding ItemImageSource,ElementName=_this}" SelectedItem="{Binding SelectedImage,ElementName=_this,Mode=TwoWay}" SelectedIndex="{Binding SelectedIndex,ElementName=_this,Mode=TwoWay}"><ListBox.Style><Style TargetType="{x:Type ListBox}"><Setter Property="ItemTemplate"><Setter.Value><DataTemplate><Border BorderBrush="Transparent"  BorderThickness="1" CornerRadius="3" Margin="6"><Image Source="{Binding Path=UriSource}" Stretch="Fill" Width="{Binding ImageWidth,ElementName=_this}" Height="auto" Margin="6"/><!--{Binding Path=UriSource}--></Border></DataTemplate></Setter.Value></Setter></Style></ListBox.Style></ListBox>
</UserControl>

As in the sample, when i bind a List<BitmapImage>. It works (Display Images).

But when I bind to a list of object (custom class) that contain TheImage (BitmapImage). I'll must to change the source of my control (By Replacing {Binding Path=UriSource} by{Binding Path=TheImage.UriSource}).

So how can I do a DisplayMemberPath for my CustumControl?

Thank you for reading. If there are any detail that may help you to understand me, I'm waiting for your reply.