调整图层及其子图层的大小 - CoreAnimation

Question

我有一个 CALayer A 和一个子层 B 我想调整 A 的大小（缩小）所以我将动画添加到我的图层 A 但是当我提交动画子层 B 时并没有缩小。它的大小保持不变（但它的位置随着其超层边界的变化而变化） 如何使我的 B 层与 A 动画一起调整大小？

这是我写的：

 CABasicAnimation *fadeInAnimation; 
 fadeInAnimation=[CABasicAnimation animationWithKeyPath:@"opacity"];
 fadeInAnimation.repeatCount = 1;
 fadeInAnimation.autoreverses = NO;
 fadeInAnimation.fromValue = [NSNumber numberWithFloat:1.0];
 fadeInAnimation.toValue = [NSNumber numberWithFloat:0.0];

 CABasicAnimation *shrinkAnimation;
 shrinkAnimation = [CABasicAnimation animationWithKeyPath:@"bounds.size"];
 shrinkAnimation.repeatCount = 1;
 shrinkAnimation.autoreverses = NO;
 shrinkAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]; 
 shrinkAnimation.toValue = [NSValue valueWithCGSize:CGSizeMake(0, 0)];

 aniGroupOFF = [[CAAnimationGroup animation] retain];
 aniGroupOFF.delegate = self;
 aniGroupOFF.duration = ANI_DURATION;
 aniGroupOFF.animations = [NSArray arrayWithObjects:shrinkAnimation, fadeInAnimation, nil]; 

然后提交：

[self addAnimation:aniGroupOFF forKey:@"shrinkAndFade"];
self.opacity = 0.0;

答案：

CABasicAnimation *shrinkAnimation;
    shrinkAnimation = [CABasicAnimation animationWithKeyPath:@"transform"]; //use transform instead of bounds.size
    shrinkAnimation.repeatCount = 1;
    shrinkAnimation.autoreverses = NO;
    shrinkAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]; 
    shrinkAnimation.toValue = [NSValue valueWithCATransform3D:CATransform3DScale(self.transform, 0.1, 0.1, 1.0)];

    aniGroupOFF = [[CAAnimationGroup animation] retain];
    aniGroupOFF.delegate = self;
    aniGroupOFF.duration = ANI_DURATION;
    aniGroupOFF.animations = [NSArray arrayWithObjects:shrinkAnimation, nil]; 

Answer 1

实现这一点的最简单方法是为 keyPath 设置动画“transform.scale”而不是“bounds.size”。

如果您坚持使用“bounds.size”，则需要在 A 层上实现 layoutSublayers 或在 A 的委托上实现 layoutSublayersOfLayer:(CALayer*)aLayer，并在该实现中手动调整 B 的大小。