我想同时影响图层变换的比例和平移，但只运行平移动画。这是错误的代码...
在这里，我使用 scale.y 的键路径创建缩放动画：
self.mainImage.layer.anchorPoint = CGPointMake(0.5, 1);
CAKeyframeAnimation *mainAnimationScale = [CAKeyframeAnimation animationWithKeyPath:@"transform.scale.y"];
mainAnimationScale.duration = 0.75;
mainAnimationScale.repeatCount = 0;
mainAnimationScale.removedOnCompletion = YES;
mainAnimationScale.autoreverses = NO;
mainAnimationScale.fillMode = kCAFillModeForwards;
mainAnimationScale.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:1.0],
[NSNumber numberWithFloat:1.0],
[NSNumber numberWithFloat:0.7],
[NSNumber numberWithFloat:1.0],
[NSNumber numberWithFloat:0.85],
[NSNumber numberWithFloat:1.0],
nil];
mainAnimationScale.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0],
[NSNumber numberWithFloat:0.65],
[NSNumber numberWithFloat:0.72],
[NSNumber numberWithFloat:0.84],
[NSNumber numberWithFloat:0.91],
[NSNumber numberWithFloat:1],
nil];
在这里，我使用翻译的键路径创建翻译动画.y：
CAKeyframeAnimation *mainAnimationTrans = [CAKeyframeAnimation animationWithKeyPath:@"transform.translation.y"];
mainAnimationTrans.duration = 0.75;
mainAnimationTrans.repeatCount = 0;
mainAnimationTrans.removedOnCompletion = YES;
mainAnimationTrans.autoreverses = NO;
mainAnimationTrans.fillMode = kCAFillModeForwards;
mainAnimationTrans.values = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:-250.0],
[NSNumber numberWithFloat:-250.0],
[NSNumber numberWithFloat:0],
nil];
mainAnimationTrans.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0],
[NSNumber numberWithFloat:0.65],
[NSNumber numberWithFloat:1],
nil];
在这里，我将它们组合在一起并将它们应用于UIView的层：
CAAnimationGroup *theGroup = [CAAnimationGroup animation];
theGroup.duration = 0.75;
theGroup.repeatCount = 0;
theGroup.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
theGroup.animations = [NSArray arrayWithObjects:mainAnimationTrans, mainAnimationScale, nil];
[self.mainImage.layer addAnimation:theGroup forKey:@"layerAnimation"];
我最初尝试像这样将动画直接添加到图层中，但这也不起作用：
[self.mainImage.layer addAnimation:mainAnimationTrans forKey:@"transform.scale.y"];
[self.mainImage.layer addAnimation:mainAnimationTrans forKey:@"transform.translation.y"];
我已经尝试了我能想到的 keyPath 值的每个字符串，我猜这与我正在对转换的两个方面进行动画处理这一事实有关，但我认为使用该组可以解决这个问题。 唉......
完成这项工作的关键是组合转换。我不知道为什么我没有早点意识到这一点，因为它是基本的矩阵数学......我想我的同事昨天甚至提到了它。咳咳。
无论如何，我要做的动画是让一个项目下拉并在到达目的地后反弹。这是代码：
self.mainImage.layer.anchorPoint = CGPointMake(0.3, 1.0);
CAKeyframeAnimation *mainImageAnimation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
mainImageAnimation.duration = 0.75;
mainImageAnimation.repeatCount = 0;
mainImageAnimation.removedOnCompletion = NO;
mainImageAnimation.autoreverses = NO;
mainImageAnimation.fillMode = kCAFillModeForwards;
mainImageAnimation.values = [NSArray arrayWithObjects:
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, -250, 0), 1, 1, 1)],
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, 17, 0), 1, 1, 1)],
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, 17, 0), 1.2, .8, 1)],
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, 17, 0), .85, 1.15, 1)],
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, 17, 0), 1.1, .9, 1)],
[NSValue valueWithCATransform3D:CATransform3DScale(CATransform3DMakeTranslation(-8, 17, 0), 1, 1, 1)],
nil];
mainImageAnimation.keyTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0],
[NSNumber numberWithFloat:0.6],
[NSNumber numberWithFloat:0.65],
[NSNumber numberWithFloat:0.78],
[NSNumber numberWithFloat:0.88],
[NSNumber numberWithFloat:1],
nil];
mainImageAnimation.timingFunctions = [NSArray arrayWithObjects:
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear],
nil];
[self.mainImage.layer addAnimation:mainImageAnimation forKey:@"transform"];
注意事项：
- 若要实现多个转换属性，请将 CATransform3DMakeXXX 函数的结果提供给 CATransform3DXXX 函数的转换参数，从而组合各个转换。
- 对于矩阵数学，变换的顺序很重要：你提供给矩阵的最后一件事将是应用的第一件事。就我而言，我希望在缩放之前应用翻译，因此我首先必须创建一个缩放转换并将其应用于后续的转换转换。 更改图层
- 的锚点会更改图层的位置。就我而言，我需要 ancor 点是不对称的，您可以看到我如何解释平移变换中位置的变化：它的休息位置不是 0，0 而是 -8，17。
希望这有帮助！
与问题不同，但相关，我试图将两个CAKeyFrameAnimation，旋转和缩放结合起来。
CAKeyframeAnimation *wiggle = [CAKeyframeAnimation animationWithKeyPath:@"transform.rotation"];
wiggle.values = @[ @0.0, @-0.15, @0.0, @0.15, @-0.15, @0.0];
wiggle.keyTimes = @[ @0.0, @0.2, @0.4, @0.6, @0.8, @1.0];
wiggle.duration = 0.5;
CAKeyframeAnimation *resize = [CAKeyframeAnimation animationWithKeyPath:@"transform.scale"];
resize.duration = 0.5;
resize.values = @[@1.0, @1.5, @1.0];
resize.keyTimes = @[@0.0, @0.5, @1.0];
单独添加动画不起作用，因为只发生了旋转。
[self.layer addAnimation:wiggle forKey:kAnimationKey];
[self.layer addAnimation:resize forKey:kAnimationKey];
但是当我创建一个包含两个CAKeyFrameAnimations的动画组时，它起作用了。
CAAnimationGroup *animGroup = [[CAAnimationGroup alloc] init];
animGroup.animations = @[wiggle, resize];
animGroup.duration = 0.5;
[self.layer addAnimation:animGroup forKey:kAnimationKey];