关于'CALayer position contains

异常

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

http://blog.csdn.net/sun2728/article/details/51925183