title: Get storyboard-defined UINavigationController from AppDelegate
body: <p>In storyboard, I have an introductory view controller which fades to a UINavigationController. </p>
  
  <pre><code>      |   |      |   |
     -&gt; |   |  -&gt;  |   |     
        |   |      |   |
       ViewCtrl   NavCtrl
  </code></pre>
  
  <p>I would like to get a reference to the navigation controller from the app delegate (like the @Guillaume answer does in <a href="https://stackoverflow.com/questions/8779808/how-to-use-custom-navigationcontroller-in-appdelegate-by-using-a-storyboard">this question</a>).</p>
  
  <p>Here's how I'm trying to access it:</p>
  
  <pre><code>UIApplication.sharedApplication.delegate.window.rootViewController.navigationController;
  </code></pre>
  
  <p>But the navigation controller is nil.</p>
  
  <p>Any notion why the navController is nil or what I can do to get a reference to it? </p>