2012年7月16日，UIViewAnimation

UIView *fromView, *toView;
    
    if ([self.frontView superview] != nil)
    {
        fromView = self.frontView;
        toView = self.backView;
        NSLog(@"yes");
    }
    else
    {
        fromView = self.backView;
        toView = self.frontView;
    }
    
    [UIView transitionFromView:fromView
                        toView:toView
                      duration:1.0
                       options:options
                    completion:^(BOOL finished) {
                        // animation completed
                    }];

UIViewAnimationOptions transitionOptions = ([self.frontView superview] != nil) ?
    UIViewAnimationOptionTransitionFlipFromLeft : UIViewAnimationOptionTransitionFlipFromRight;

有这几种方式
UIViewAnimationOptionTransitionNone            = 0 << 20, // default
    UIViewAnimationOptionTransitionFlipFromLeft    = 1 << 20,
    UIViewAnimationOptionTransitionFlipFromRight   = 2 << 20,
    UIViewAnimationOptionTransitionCurlUp          = 3 << 20,
    UIViewAnimationOptionTransitionCurlDown        = 4 << 20,
    UIViewAnimationOptionTransitionCrossDissolve   = 5 << 20,
    UIViewAnimationOptionTransitionFlipFromTop     = 6 << 20,
    UIViewAnimationOptionTransitionFlipFromBottom  = 7 << 20,

单个View动画效果

[UIView animateWithDuration:1 delay:0.5f options:UIViewAnimationOptionAutoreverse animations:^{
        self.frontView.alpha=0.0f;
    } completion:^(BOOL finished) {
        self.frontView.alpha=1.0f;
    }];