我的代碼是這樣的：//ViewController.m//核心動畫#import"ViewController.h"@interfaceViewController()@property(weak,nonatomic)IBOutletUIImageView*imageView;@end@implementationViewController-(void)viewDidLoad{[superviewDidLoad];}-(void)touchesBegan:(NSSet*)toucheswithEvent:(UIEvent*)event{[UIViewanimateWithDuration:3animations:^{self.imageView.layer.transform=CATransform3DMakeRotation(M_PI,0,1,1);}];}-(void)didReceiveMemoryWarning{[superdidReceiveMemoryWarning];}@end但是這樣做旋轉了一次就不在旋轉了。請問如何實現不停的旋轉呢？（按照Y軸）