title: BackgroundWorker: Block DoWork until ProgressUpdated completes
body: <p>I have the two functions using a shared variable, and the <code>BackgroundWorker</code> is changing it's value before the UI thread can use it.</p>
  
  <p>Is it possible to block the BackgroundWorker's <code>DoWork</code> function, while the ui thread updates via <code>ProgressChanged</code>? </p>
  
  <p>Or should I just lock the shared variable while it's being used in <code>ProgressChanged</code> until the UI thread finishes? </p>