iOS 图片360度循环旋转

初始化动画

-(void)initAnimationWithImageView:(UIImageView *)imageView onSpeed:(float)speed
{
CABasicAnimation* rotationAnimation;
rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];
rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * speed ];
rotationAnimation.duration = 0.2;
rotationAnimation.cumulative = YES;
rotationAnimation.repeatCount = FLT_MAX;
[imageView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];
}

启动动画

-(void)startAnimationWithImageView:(UIImageView *)imageView
{
CFTimeInterval pausedTime = [imageView.layer timeOffset];
imageView.layer.speed = 1.0;
imageView.layer.timeOffset = 0.0;
imageView.layer.beginTime = 0.0;
CFTimeInterval timeSincePause = [imageView.layer convertTime:CACurrentMediaTime()
fromLayer:nil] - pausedTime;
imageView.layer.beginTime = timeSincePause;
}

暂停动画

-(void)pauseAnimationWithImageView:(UIImageView *)imageView
{
CFTimeInterval pausedTime = [imageView.layer convertTime:CACurrentMediaTime() fromLayer:nil];
imageView.layer.speed = 0.0;
imageView.layer.timeOffset = pausedTime;
}