title: dispatch_after looped / repeated
body: <p>I am trying to create a loop like this:</p>
  
  <pre><code>while (TRUE){
    dispatch_after(...{
      &lt;some action&gt;
    });
  }
  </code></pre>
  
  <p>After a viewDidLoad. The idea is to repeat the dispatch_after repeatedly. The dispatch_after waits two seconds before doing the action.</p>
  
  <p>This does not work - the screen just blanks? Is it stuck in looping or ...?</p>