Hidden features of WPF and XAML?

Question

Here is a large number of hidden features discussed for variety of languages. Now I am curious about some hidden features of XAML and WPF?

One I have found is the header click event of a ListView

<ListView x:Name='lv' 
      Height="150" 
      GridViewColumnHeader.Click="GridViewColumnHeaderClickedHandler">

The GridViewColumnHeader.Click property is not listed.

Some of relevant features so far:

• Multibinding combined with StringFormat

• TargetNullValue to bindings

• TextTrimming property

• Markup extensions

• Adding Aero effect to Window

• Advanced "caption" properties

• XAML Converters

See also:

1. Hidden features of C#
2. Hidden features of Python
3. Hidden features of ASP.NET
4. Hidden features of Perl
5. Hidden features of Java
6. Hidden features of VB.NET
7. Hidden features of PHP
8. Hidden features of Ruby
9. Hidden features of C
10. And So On........

Answer 1

Multibinding (combined with StringFormat):

<TextBlock>
  <TextBlock.Text>
    <MultiBinding StringFormat="{}{0}, {1}">
      <Binding Path="LastName" />
      <Binding Path="FirstName" />
    </MultiBinding>
  </TextBlock.Text>
</TextBlock>