title: viewDidAppear not getting called
body: <p>In my main UIViewController I am adding a homescreen view controller as subviews:</p>
  
  <pre><code>   UINavigationController *controller = [[UINavigationController alloc] initWithRootViewController:vc];
          controller.navigationBarHidden = YES;
          controller.view.frame = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height);
          [self addChildViewController:controller];
          [self.view insertSubview:controller.view atIndex:0];
          [controller didMoveToParentViewController:self];    
  </code></pre>
  
  <p>The issue is that viewDidAppear and viewWillAppear is only called once, just like viewDidLoad. Why is this? How do I make this work?</p>
  
  <p>Basically inside vc I am not getting viewDidAppear nor viewWillAppear.</p>
  
  <p>I also just tried adding the UIViewController without the navigation controller and it still doesn't work:</p>
  
  <pre><code>vc.view.frame = CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.height);
          [self addChildViewController:vc];
          [self.view insertSubview:vc.view atIndex:0];
          [vc didMoveToParentViewController:self];    
  </code></pre>