iOS设置imageView转圈功能

闲话少说，直接上代码！

UIImageView *imageView=[[UIImageView alloc]initWithFrame:CGRectMake(0, 0, imageBgWH, imageBgWH)];
    
    imageView.image=[UIImage imageNamed:@"testing_tree"];
    
    imageView.center=imageBg.center;
    
//    NSLog(@"%f",imageView.top);
    
    [self.view addSubview:imageView];

添加要旋转的图片

- (CADisplayLink *)link
{
    if (!_link) {
        self.link = [CADisplayLink displayLinkWithTarget:self selector:@selector(up)];
    }
    return _link;
}
懒加载link

 [self.link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];

- (void)up
{
    // 1/60秒 * 45
    // 规定时间内转动的角度 == 时间 * 速度
    CGFloat ang = self.link.duration * M_PI_2;
    imageBg.transform = CGAffineTransformRotate(imageBg.transform, ang);
}

新手分享，勿喷！