旋转加载动画

1.自定义UIImageView

 UIImageView *loadingImage = [[UIImageView alloc] initWithFrame:CGRectMake(self.width/2-15, self.height/2-15, 31, 31)];

 loadingImage.image = [UIImage imageNamed:@"icon_video_loading"];

 loadingImage.userInteractionEnabled = YES;

[self addSubview:self.loadingImage];

2.开始动画

-(void)showPlayLoading{

    if (![self.loadingImage.layer animationForKey:@"loading"]) {

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

        //默认是顺时针效果，若将fromValue和toValue的值互换，则为逆时针效果

        animation.fromValue = [NSNumber numberWithFloat:0.0f];

        animation.toValue = [NSNumber numberWithFloat: M_PI *2];

        animation.duration=3;

        animation.autoreverses=NO;

        animation.fillMode = kCAFillModeForwards;

        animation.repeatCount = MAXFLOAT; //如果这里想设置成一直自旋转，可以设置为MAXFLOAT，否则设置具体的数值则代表执行多少次

        [self.loadingImage.layeraddAnimation:animationforKey:@"loading"];

    }

}

3.结束动画（合适的位置结束加载动画）

-(void)stopPlayLoading{

    [self.loadingImage.layer removeAnimationForKey:@"loading"];

    self.loadingImage.hidden = YES;

}