iphone - 如何从 animationDidStop 中删除 CALayer 对象？

Question

我正在尝试学习 iOS/iPhone 的核心动画。我的根层包含很多子层( Sprite )，当它们被移除时它们应该旋转......

我的计划是添加一个旋转动画，然后在调用 animationDidStop 时移除 Sprite 。问题是 Sprite 层不是 animationDidStop 的参数!

从 animationDidStop 中找到特定 Sprite 层的最佳方法是什么？有没有更好的方法让 Sprite 在被移除时旋转？ (理想情况下我想使用 kCAOnOrderOut 但我无法让它工作)

-(void) eraseSprite:(CALayer*)spriteLayer {
    CABasicAnimation* animSpin = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    animSpin.toValue = [NSNumber numberWithFloat:2*M_PI];
    animSpin.duration = 1; 
    animSpin.delegate = self;
    [spriteLayer addAnimation:animSpin forKey:@"eraseAnimation"];    
}



- (void)animationDidStop:(CAAnimation *)theAnimation finished:(BOOL)flag{
    // TODO check if it is an eraseAnimation
    //      and find the spriteLayer

    CALayer* spriteLayer = ??????   
    [spriteLayer removeFromSuperlayer]; 
}

Answer 1

在这里找到这个答案 cocoabuilder但基本上你为正在动画的 CALayer 添加一个键值到 CABasicAnimation。

- (CABasicAnimation *)animationForLayer:(CALayer *)layer
{
     CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"opacity"];
     /* animation properties */
     [animation setValue:layer forKey:@"animationLayer"];
     [animation setDelegate:self];
     return animation;
}

然后在animationDidStop回调中引用它

- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
 {
     CALayer *layer = [anim valueForKey:@"animationLayer"];
     if (layer) {
         NSLog(@"removed %@ (%@) from superview", layer, [layer name]);
         [layer removeFromSuperlayer];
     }
 }