ios - CoreAnimation 旋转一个对象并同时改变它的位置

Question

我想做的是左右旋转 View ，同时上下移动它的位置。

这是我的代码:

CGAffineTransform leftWobble = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(-12.0));
CGAffineTransform rightWobble = CGAffineTransformRotate(CGAffineTransformIdentity, RADIANS(12.0));

flyingGuy.transform = leftWobble;  // starting point

[UIView beginAnimations:@"wobble" context:flyingGuy];
[UIView setAnimationRepeatAutoreverses:YES];
[UIView setAnimationRepeatCount:1000];
[UIView setAnimationDuration:1.3];
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:@selector(wobbleEnded:finished:context:)];

flyingGuy.transform = rightWobble;
CGRect frame = flyingGuy.frame;
frame.origin.y += 10;
[flyingGuy setFrame:frame];

[UIView commitAnimations];


- (void)wobbleEnded:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context  {
    if ([finished boolValue]) {
        UIView* item = (UIView *)context;
        item.transform = CGAffineTransformIdentity;
    }
}

使用当前代码， View 大小会随着向上或向下移动而改变。有什么建议吗？

Answer 1

不要在设置转换后设置或获取框架!

来自文档:

Warning If the transform property is not the identity transform, the value of this property is undefined and therefore should be ignored.

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你应该怎么做

更改 View 的 center 属性。无论如何你只是在改变位置，当你应用了转换时这是安全的。