CATransition 过度动画

    1.创建
    CATransition * transition =  [CATransition animation];
    
    transition.duration = 2;
        

    2.设置过度样式
    transition.type = kCATransitionMoveIn; //控制动画样式,
    transition.subtype = kCATransitionFromTop; //控制方向
      

    3.添加动画
    [self.changeView.layer addAnimation:transition forKey:nil];