CGContextRef context = UIGraphicsGetCurrentContext();   [UIView beginAnimations:nil context:context];  [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];   [UIView setAnimationDuration:1.0];  // Apply the animation to the backdrop  [UIView setAnimationTransition:       UIViewAnimationTransitionCurlUp      forView:myView cache:YES];  // Exchange the two foreground views   [myView exchangeSubviewAtIndex:0      withSubviewAtIndex:1];   [UIView commitAnimations];