title: Switch View with animation
body: <p>I must change a view. In a view I've a button with this code:</p>
  
  <pre><code>    FormazioneViewController *formazioneC = [[FormazioneViewController alloc] initWithNibName:@"FormazioneView" bundle:nil];
  
  self.formazioneViewController= formazioneC;
  
  [UIView beginAnimations:@"View Flip" context:nil];
  [UIView setAnimationDuration:1.25];
  [UIView setAnimationDelegate:self];
  [UIView setAnimationDidStopSelector:@selector(animationDidStop)];
  [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
  
  [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];
  
  [self viewWillDisappear:YES];
  [self viewDidDisappear:YES];
  [self.view addSubview:formazioneViewController.view];
  [formazioneViewController viewWillAppear:YES];
  [formazioneViewController viewDidAppear:YES];
  
  [UIView commitAnimations];
  </code></pre>
  
  <p>and I add a superview, now i must return in this view and i use a button with this code:</p>
  
  <pre><code>    [UIView beginAnimations:@"View Flip" context:nil];
  [UIView setAnimationDuration:1.25];
  [UIView setAnimationDelegate:self];
  [UIView setAnimationDidStopSelector:@selector(animationDidStop)];
  [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
  [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:YES];
  
  [self viewWillDisappear:YES];
  [self viewDidDisappear:YES];
  
  [self.view removeFromSuperview];
  
  [****** viewWillAppear:YES];
  [****** viewDidAppear:YES];
  
  [UIView commitAnimations];
  </code></pre>
  
  <p>What is the object where i must call the viewWillAppear and ViewDidAppear method??
  Thanks</p>
  
  <p>Sorry for my bad english!</p>