'CALayer position contains NaN: [nan nan]'异常

异常一

Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [nan nan]'

原因

计算高度，宽度，CGRectMake设置等中存在错误,看看是不是除0等操作了

异常二

CALayer position contains NaN: [187.5 nan]. Layer: <CALayer:0x281d9c0a0; position = CGPoint (100 100); bounds = CGRect (0 0; 200 200); delegate = <UIImageView: 0x101a8cc50; frame = (0 0; 200 200); gestureRecognizers = <NSArray: 0x2816f39c0>; layer = <CALayer: 0x281d9c0a0>>; opaque = YES; allowsGroupOpacity = YES; >

这种下面会有一串的 block_invoke错误，这时候不要在意这些细节，抓住主要矛盾，主要排查看看是否有四则运算没有考虑全作用域 即可

参考链接：https://www.jianshu.com/p/b1b8d8eab874