title: Silverlight: Force Canvas to Invalidate or Repaint itself?
body: <p>I have a Silverlight application which has on it a Canvas.
  On that Canvas, I dynamically "paint" a bunch of stuff, but adding controls to the canvas.</p>
  
  <p>I have a button outside the Canvas area which clears the content.
  The objects are removed (successfully).   However, the Canvas area does not refresh itself immediately; it currently requires a MouseOver or other event for the Canvas itself.</p>
  
  <p>What is the simplest way to have an external object invalidate a Canvas?  I'm sure I'm missing something simple!</p>