[UIView beginAnimations:nil context:nil];
              [UIView setAnimationRepeatAutoreverses:YES];//动画是否返回
  
    [UIView setAnimationDuration:0.3];
  
    button.alpha =0;
  
  
    [UIView commitAnimations];

CATransition的type属性
 
1.#define定义的常量
     kCATransitionFade   交叉淡化过渡
     kCATransitionMoveIn 新视图移到旧视图上面
     kCATransitionPush   新视图把旧视图推出去
     kCATransitionReveal 将旧视图移开,显示下面的新视图
 
2.用字符串表示
     pageCurl            向上翻一页
     pageUnCurl          向下翻一页
     rippleEffect        滴水效果
     suckEffect          收缩效果，如一块布被抽走
     cube                立方体效果
     oglFlip             上下翻转效果 
 
- (void)MyCAnimation1 {  
     
    CATransition *animation = [CATransition animation]; 
    //动画时间 
    animation.duration = 1.0f; 
    //display mode, slow at beginning and end 
    animation.timingFunction = UIViewAnimationCurveEaseInOut; 
    //过渡效果 
    animation.type = kCATransitionMoveIn; 
    //过渡方向 
    animation.subtype = kCATransitionFromTop; 
    //添加动画 
    [imageView.layer addAnimation:animation forKey:nil]; 
} 
 
- (void)MyCAnimation2 {  
     
    CATransition *animation = [CATransition animation]; 
    //动画时间 
    animation.duration = 1.0f; 
    //display mode, slow at beginning and end 
    animation.timingFunction = UIViewAnimationCurveEaseInOut; 
    //在动画执行完时是否被移除 
    animation.removedOnCompletion = NO; 
    //过渡效果 
    animation.type = @"pageCurl"; 
    //过渡方向 
    animation.subtype = kCATransitionFromRight; 
    //暂时不知,感觉与Progress一起用的,如果不加,Progress好像没有效果 
    animation.fillMode = kCAFillModeForwards; 
    //动画停止(在整体动画的百分比). 
    animation.endProgress = 0.7; 
    [imageView.layer addAnimation:animation forKey:nil]; 
} 
 
- (void)MyCAnimation3 {  
     
    CATransition *animation = [CATransition animation]; 
    //动画时间 
    animation.duration = 1.0f; 
    //display mode, slow at beginning and end 
    animation.timingFunction = UIViewAnimationCurveEaseInOut; 
    //过渡效果 
    animation.type = @"pageUnCurl"; 
    //过渡方向 
    animation.subtype = kCATransitionFromRight; 
    //暂时不知,感觉与Progress一起用的,如果不加,Progress好像没有效果 
    animation.fillMode = kCAFillModeBackwards; 
    //动画开始(在整体动画的百分比). 
    animation.startProgress = 0.3; 
    [imageView.layer addAnimation:animation forKey:nil]; 
}