UIViewAnimation翻转不起作用

Question

在UIView子类中，我有以下内容：

self.frontImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"front"]];
self.backImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"back"]];
[self addSubview:self.backImageView];


[UIView animateWithDuration:0.5
                          delay:0.0
                        options:UIViewAnimationOptionTransitionFlipFromLeft
                     animations:^{
                         [self.backImageView removeFromSuperview];
                         [self addSubview:self.frontImageView];}

                     completion:^(BOOL finished){
                         //nothing
                     }];

但我不明白翻转动画。前面的图像视图会立即出现。我做错了什么？

Answer 1

你犯了一个愚蠢的错误

animateWithDuration:delay:options:animations:completion:

而不是

transitionFromView:toView:duration:options:completion:

你的代码应该是：

[UIView transitionFromView:backImageView
                    toView:frontImageView
                  duration:0.5
                   options:UIViewAnimationOptionTransitionFlipFromLeft
                completion:^(BOOL finished) {
                    // animation completed
                }];