Is there a way for two DataTemplates to share some elements?

Question

Something like a template or base DataTemplate which both DataTemplates extend or inherit so I don't have to duplicate XAML.

Answer 1

What about UserControls? Create a base UserControl and then extend the second one?

<DataTemplate>
  <local:MyBase />
</DataTemplate>

And extend it like this?

<DataTemplate>
  <local:MyBase />
  <local:SomeOtherStuff />
</DateTemplate>

Answer 2

You can nest DataTemplates. Here an is example

<DataTemplate x:Key="InnerTemplate">
    <TextBlock Text="{Binding}" Foreground="Purple" />
</DataTemplate>

<DataTemplate x:Key="OuterTemplate">
    <StackPanel>
        <TextBlock Text="Header" Foreground="Red" />
        <ContentPresenter Content="{Binding}" ContentTemplate="{StaticResource InnerTemplate}" />
    </StackPanel>
</DataTemplate>

In this case I just have a List bound to a listbox, and its itemtemplate set to the OuterTemplate template.

<ListBox x:Name="_lbTest" Grid.Row="1" ItemTemplate="{StaticResource OuterTemplate}" ></ListBox>