title: Reload UIView With UIViewAnimationOptionTransitionCurlUp Animation
body: <p>I need to reload (update) the self.view with UIViewAnimationOptionTransitionCurlUp animation. Visually, old view animates with curl-up effect and new updated view is presented after it. I could not find a better approach than to create a current view's screenshot, place it on top of all, and apply animation to roll it up and remove. Then updated view elements would be nicely presented after old view curled up.</p>
  
  <p>However, curl-up does not work. The transition becomes fade out rather than curl up. What's wrong? The code is below.</p>
  
  <pre><code>UIGraphicsBeginImageContextWithOptions(self.view.frame.size, NO, 0.0);
  [self.view.layer renderInContext:UIGraphicsGetCurrentContext()];
  UIImage *screenshot = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  
  UIView* screenView = [[UIView alloc] initWithFrame:self.view.frame];
  screenView.tag = TAG_SCREENSHOT_VIEW;
  screenView.backgroundColor = [UIColor colorWithPatternImage:screenshot];
  [self.view addSubview:screenView];
  [screenView.superview bringSubviewToFront:screenView];
  
  [UIView transitionWithView:screenView
                    duration:1.0f
                     options:UIViewAnimationOptionTransitionCurlUp
                  animations:^ { screenView.alpha = 0.0f; }
                  completion:^ (BOOL finished) {
                      [screenView removeFromSuperview];
                  }];
  </code></pre>