ios - animationDidStop : finished: delegate method not getting called

Question

我想在前一个动画例程完成后立即开始一个新的动画例程。然而，当前一个确实完成时，新的不会被触发，因为没有调用委托(delegate)方法。我已经委派了一个 View Controller 来处理按钮的 CALayer 的动画。 “buttonSlide”是以前的动画，而“buttonFade”是新动画。 这是代码片段:-

-(void)viewWillAppear:(BOOL)animated{

NSLog(@"TimeView appearing...");
[super viewWillAppear:animated];
[self pressButton:nil]; // Shows current time as soon as TimeView appears

//    Silver challenge
CABasicAnimation *buttonSlide= [CABasicAnimation animationWithKeyPath:@"position"];
[buttonSlide setFromValue:[NSValue valueWithCGPoint:CGPointMake(320, 191+15)]];
[buttonSlide setToValue:[NSValue valueWithCGPoint:CGPointMake(160, 191+15)]];
[buttonSlide setDuration:.12];

[button.layer addAnimation:buttonSlide forKey:@"buttonSlide"];

[buttonSlide setDelegate:self];

CABasicAnimation *buttonFade= [CABasicAnimation animationWithKeyPath:@"opacity"];
[buttonFade setFromValue:[NSNumber numberWithFloat:.2]];
[buttonFade setToValue:[NSNumber numberWithFloat:1]];
[buttonFade setDuration:10];


}

-(void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
  NSLog(@"%@ finshed: %d",anim,flag);
  CAAnimation *buttonFade= [button.layer animationForKey:@"opacity"];
  [button.layer addAnimation:buttonFade forKey:@"buttonFade"];

}

委托(delegate)方法没有记录到控制台，因为它甚至没有被调用。请协助。

Answer 1

把这个:

[buttonSlide setDelegate:self];

之前:

[button.layer addAnimation:buttonSlide forKey:@"buttonSlide"];

这样就变成了:

[buttonSlide setDelegate:self];
[button.layer addAnimation:buttonSlide forKey:@"buttonSlide"];

会起作用。

希望这对您有所帮助。