http://www.cocoachina.com/ios/20151230/14822.html

序

CAReplicatorLayer可以复制自己子层的layer,并且复制的出来的layer和原来的子layer拥有相同的动效。然后通过设置一些属性，就可以完成很酷的效果，非常强大。。

效果

建议先下载demo,再结合下面的分析，会好理解点。地址https://github.com/Resory/RYReplicatorLayer

UIBezierPath *tPath = [UIBezierPath bezierPath];

[tPath moveToPoint:CGPointMake(SYS_DEVICE_WIDTH/2.0, 200)];

[tPath addQuadCurveToPoint:CGPointMake(SYS_DEVICE_WIDTH/2.0, 400) controlPoint:CGPointMake(SYS_DEVICE_WIDTH/2.0 + 200, 20)];

[tPath addQuadCurveToPoint:CGPointMake(SYS_DEVICE_WIDTH/2.0, 200) controlPoint:CGPointMake(SYS_DEVICE_WIDTH/2.0 - 200, 20)];

[tPath closePath];

UIView *tView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 10, 10)];

tView.center = CGPointMake(SYS_DEVICE_WIDTH/2.0, 200);

tView.layer.cornerRadius = 5;

tView.backgroundColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0];

CAKeyframeAnimation *loveAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];

loveAnimation.path = tPath.CGPath;

loveAnimation.duration = 8;

loveAnimation.repeatCount = MAXFLOAT;

[tView.layer addAnimation:loveAnimation forKey:@"loveAnimation"];

_loveLayer = [CAReplicatorLayer layer];

_loveLayer.instanceCount = 40; // 复制39个子layer+原本的子layer共40个layer

_loveLayer.instanceDelay = 0.2; // 每隔0.2出现一个layer

_loveLayer.instanceColor = [UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0].CGColor;

_loveLayer.instanceGreenOffset = -0.03; // 颜色值递减。

_loveLayer.instanceRedOffset = -0.02; // 颜色值递减。

_loveLayer.instanceBlueOffset = -0.01; // 颜色值递减。

CAReplicatorLayer里面还有一个instanceTransform属性，musicLayer就是用它的instanceTransform属性做的。所以还有很多效果可以做。就看你脑洞够不够大了。
如果你有疑问或者发现错误请留言给我。3Q~~