title: WPF RichTextBox Custom Text Property
body: <p>Ok, I'm trying to add a "custom property" to a piece of text in a RichTextBox control. I thought it would be easy, but apparently not :-)</p>
  
  <p>The basic functionality I want is to be able to set a property on a particular word and be able to detect, when a word is double clicked, if that property is there or not.</p>
  
  <p>My intial approach was to create a new DP and apply it to the text, but TextRange isn't actually a DependencyObject and Reflector shows it only accepts certain DPs that it maps directly to "real" properties.</p>
  
  <p>Unfortunately I can't seem to find any other "hook" to let me do this. I can't inherit from any of the things that I CAN apply to text, as everything I need is either sealed, or contains internal abstracts, so I'm at a bit of a loss.</p>
  
  <p>I could just keep track of ranges that have the property externally, and update that as the text is updated, but that sounds pretty horrible, and I really don't want to have to create my own RichTextBox just for this one feature!</p>
  
  <p>Any suggestions would be most welcome :-)</p>