title: Refreshing ViewController after popViewControllerAnimated
body: <p>I have a root ViewController (RootViewController) that calls pushViewController to display another ViewController (DetailViewController). In DetailViewController I make edits that affect the contents displayed in the root ViewController. So I need to redraw the view in RootViewController after the DetailViewController is removed via popViewControllerAnimated.</p>
  
  <p>The problem is that setNeedsDisplay does not seem to work in this scenario. In the viewWillAppear method of RootViewController, I call:</p>
  
  <pre><code>[self.view setNeedsDisplay]
  </code></pre>
  
  <p>However, the contents of the RootViewController view does not update. So I am wondering if there is something about Navigation Controllers that prevents setNeedsDisplay from working.</p>
  
  <p>The only workaround I could find is that the following code, which forces a call to viewDidLoad, which redraws the entire view</p>
  
  <pre><code>self.view = nil;
  </code></pre>