title: How to know when textbox is being modified?
body: <p>I'm using the Delay binding tag of .Net 4.5 but I want to change the textbox's background color while the changes are not "committed". How can I set an IsDirty property to true while the delay is happening?</p>
  
  <p>I tried using the TextChanged event to set an IsDirty flag and then remove the flag when the bound property got set. The problem is that the TextChanged fires whenever the bound property changes and not just when the user modifies the text.</p>
  
  <p>I got it "working" in a very clunky and fragile way by monitoring the TextChanged event and the bound property. Needless to say this is very prone to bugs so I would like a cleaner solution. Is there any way to know that the textbox has been changed but not committed yet (by the Delay)?</p>