iPhone核心动画运行不顺畅?

我的应用程序中有以下核心动画代码:

-(void)startCoreAnimation

    [UIView beginAnimations:@"IconFade" context:Icon];
   [UIView setAnimationCurve:UIViewAnimationCurveLinear];
   [UIView setAnimationDuration:1];

   [UIView setAnimationRepeatAutoreverses:YES];
   [UIView setAnimationDelegate:self];
   [UIView         setAnimationDidStopSelector:@selector(animationFinished:finished:context:)];

   icon.alpha=0.0;
   [UIView commitAnimations];
   break;

然后当动画结束时:

-(void)animationFinished : (NSString *)theAnimation finished : (BOOL)flag context : (void *)context {


 ((UIView *)context).alpha = 1.0;
 ((UIView *)context).transform = CGAffineTransformIdentity;

 [self startCoreAnimation];

}

谢谢,

马丁