ios - ios如何旋转控制360度

Question

我想将控制旋转360度。我现在就那样做

#define degreesToRadians(x) (M_PI * x / 180.0)

[UIView animateWithDuration:0.25 delay:0.0 options:UIViewAnimationOptionCurveEaseOut animations:^{
    [self.crossButton setTransform:CGAffineTransformRotate(self.crossButton.transform, degreesToRadians(360))];
} completion:nil];

但是什么也没发生。你知道我在做什么错吗？

Answer 1

360度旋转变换是恒等变换，因此
对象完全没有动画。

您可以使用“基本属性动画”获得所需的效果:

[CATransaction begin];
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.byValue = @(2 * M_PI); // 360 degrees
rotationAnimation.duration = 0.25;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
[self.crossButton.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
[CATransaction commit];

更新:如果旋转量不是360度(因此最终位置不相同)
作为初始位置)，则应执行以下操作:

[CATransaction begin];
CGFloat angle = 45.0 * M_PI/180.0;
CABasicAnimation *rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.byValue = @(angle);
rotationAnimation.duration = 0.25;
rotationAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
rotationAnimation.removedOnCompletion = YES;
[CATransaction setCompletionBlock:^{
    self.crossButton.transform = CGAffineTransformRotate(self.button.transform, angle);
}];
[self.crossButton.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
[CATransaction commit];