title: Altering the ObservableCollection according to FileSystemWatcher change notification
body: <p>I'm trying to update my ObservableCollection as the FileSystemWatcher notifies changes. I know this is not possible because of cross thread operations. <br>
  So i would like to get the name of the file created/deleted/renamed when the event is fired and update it in the UI thread once the event is completed, as we do in BackgroundWorker. Can anyone tell me how to do this?</p>
  
  <p>Also tell me where i should define and start this FileSystemWatcher. Currently i've defined it in the MainViewModel.</p>
  
  <p>P.S.: I've seen similar questions in SO, but didn't get a clear picture</p>
  
  <p>Thanks In Advance,<br>
  Veer</p>