iOS开发：放大再缩小动画

之前觉得很简单，写两个基础动画嵌套即可，但是发现并不是那么回事，后面动画会覆盖前面那个，自己就写了个，看代码：

//缩放动画

[UIView animateKeyframesWithDuration:1delay:0options:0animations: ^{

    self.bgView.transform = CGAffineTransformMakeScale(0.1,0.1);

    [UIView addKeyframeWithRelativeStartTime:0relativeDuration:1animations: ^{

        self.view.transform = CGAffineTransformMakeScale(1.2,1.2);

    }];

    [UIView addKeyframeWithRelativeStartTime:1relativeDuration:1animations: ^{

        self.view.transform = CGAffineTransformMakeScale(1.0,1.0);

    }];

} completion:nil];