title: How to redraw my view in SWIFT?
body: <p>On my iPad app, I have a UIViewController with a button that open a modalView.</p>
  
  <pre><code>@IBAction func showPostCommentViewController(sender: AnyObject){
  
      let modalView = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("PostCommentViewController") as! PostCommentViewController
      modalView.modalTransitionStyle = UIModalTransitionStyle.CoverVertical
      modalView.modalPresentationStyle = UIModalPresentationStyle.FormSheet
      modalView.delegate=self
      self.presentViewController(modalView, animated: true, completion: nil)
  }
  </code></pre>
  
  <p>When I close the modalView with dismissViewControllerAnimated, I would like "refresh" my view controller (because I added new content). But as the modal view is a "formsheet" style, viewDidAppear or viewWillAppear aren't called.</p>
  
  <p>I tried to use setNeedsDisplay, but it doesn't work.</p>
  
  <p>I don't know how to do.</p>