title: What's wrong with this Objective C self.navigationController?
body: <p>What additional code do I need to add to make the below work?</p>
  
  <pre><code>- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
  {
      self.navigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
      return YES;
  }
  </code></pre>
  
  <p>It is currently throwing the error: <code>Property 'navigationController' not found on object of type 'AppDelegate</code>.</p>