UIImageView旋转动画

  _loadingView = [[UIImageView alloc]initWithFrame:CGRectMake(150, 300, 50, 50)];

    _loadingView.image = [UIImage imageNamed:@"22"];

    [self.view addSubview:_loadingView];

    CABasicAnimation* rotationAnimation;

    rotationAnimation = [CABasicAnimation animationWithKeyPath:@"transform.rotation.z"];

    rotationAnimation.toValue = [NSNumber numberWithFloat: M_PI * 2.0 ];

    rotationAnimation.duration = 0.2;

    rotationAnimation.cumulative = YES;

    rotationAnimation.repeatCount = 100000;

    

    [_loadingView.layer addAnimation:rotationAnimation forKey:@"rotationAnimation"];//开始动画

    _loadingView.layer removeAnimationForKey:<#(NSString *)#>//结束动画