title: How to get RichTextBox Undo to work better?
body: <p>I am trying to write a text editor using <code>RichTextBox</code>. My concern is now about Undo and possibly Redo features of RichTextBox.</p>
  
  <p>When I start writing in text box, say 1 minute! if I call <code>Undo</code> method, all it does is just I beleive clearing or resetting richtextbox again. How can I get it to work that it can do better, like Undoing last added word, or last added new line...I mean usual things you expect from Undo function. (The same counts for Redo also!)</p>
  
  <p>Is there properties or some options to achive this? Or I have to implement my own code? </p>