定时器+反射变换 --->模拟一个音乐播放器的音乐专辑旋转

//准备imgView

@property(nonatomic,strong) UIImageView *imgView;

@end

@implementation ViewController

- (void)viewDidLoad {

    [super viewDidLoad];

   

  

    

#pragma mark 模拟音乐播放器中的专辑旋转

    

    //准备一个背景图片

    self.imgView = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, 200, 200)];

    _imgView.center = self.view.center;

    [_imgView setImage:[UIImage imageNamed:@"音乐.png"]];

    

    [self.view addSubview:_imgView];

    

    

    //切成一个圆

    [_imgView.layer setCornerRadius:100];

    [_imgView.layer setMasksToBounds:YES];

    

#pragma mark 给音乐专辑旋转增加一个定时器

    //人眼能辨别的间隔为0.2,所以尽量在0.2左右

    [NSTimer scheduledTimerWithTimeInterval:0.08 target:self selector:@selector(rotationWithMusic) userInfo:nil repeats:YES];

    

}

-(void)rotationWithMusic

{

    _imgView.transform = CGAffineTransformRotate(_imgView.transform, 50);

}