title: How to read object's DependencyProperty in code?
body: <p>In my XAML I have an object with <code>DependencyProperty</code>:</p>
  
  <p><code>&lt;TextBlock local:Extensions.OverWidth="100"/&gt;</code></p>
  
  <p>I also have <code>MouseUp</code> handler upon this <code>TextBlock</code>. How do I get <code>OverWidth</code> property value in it?</p>