围绕其中心旋转UIView几次 [英] rotate a UIView around its center but several times

问题描述

我试图在它的中心周围旋转一些 UIView ，所以简单的代码像
（在伪代码中）：

I'm trying to rotate some UIView around its center, so the simple code goes something like (in pseudocode):

[UIView beginAnimations:@"crazyRotate" context:nil];
[UIView setAnimationDuration:1.0];
someview.transform = CGAffineTransformMakeRotation(angle);
[UIView commitAnimations]

现在如果我设置角度说M_PI /很好。
如果我将其设置为2 * M_PI，它会没有。我可以理解，矩阵转换为什么都不做什么（旋转360意味着保持在某种意义上），
，但是，我想旋转它5次（认为一个报纸旋转缩放来到你效果 - 我不是很好描述，希望有人理解）。
所以，我尝试添加设置角度为180度（M_PI），并添加嵌套 animatationBlock 。
但我想，因为我设置相同的属性（ someview.transition ），它会忽略它）。
我尝试将动画的重复计数设置为2，使用角度M_PI，但它似乎只是旋转180°，回到直线位置，然后再次启动旋转。

now if I set angle to say M_PI/2 the thing rotates nicely. if I set it to 2*M_PI, well it does "nothing". I can understand that the matrix translates to something that does nothing (rotating 360 means "stay" in a sense), yet, I want to rotate it 5 times (think of a newspaper rotate scale coming at you effect -- I'm not great at describing, hope someone understands). So, I tried adding setting angle to 180 deg (M_PI) and add a nested animatationBlock. but I guess that since I'm setting the same property (someview.transition) again it ignores it somehow). I tried setting repeat count of the animation to 2 with angle M_PI but it seems to simply rotate 180, going back to straight position and then initiating the rotate again.

所以，我有点想法，
任何帮助赞赏！
--t

So, I'm a little out of ideas, any help appreciated! --t

推荐答案

您可以在UIView的图层属性上使用以下动画。我已经测试过了。

You can use the following animation on your UIView's layer property. I've tested it.

UIView *viewToSpin = ...;    
CABasicAnimation* spinAnimation = [CABasicAnimation
                                  animationWithKeyPath:@"transform.rotation"];
spinAnimation.toValue = [NSNumber numberWithFloat:5*2*M_PI];
[viewToSpin.layer addAnimation:spinAnimation forKey:@"spinAnimation"];

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