UIView的clipToBounds属性:用于判断当前view的子view范围超出当前view后是选择截取还是不截取。
官方解释: Setting this value to YES causes subviews to be clipped to the bounds of the receiver. If set to NO, subviews whose frames extend beyond the visible bounds of the receiver are not clipped. The default value is NO.
图片实例: clipToBounds = YES
![Yes](http://7xleoh.com1.z0.glb.clouddn.com/clipToBoundsYes.png)
Yes
![No](http://7xleoh.com1.z0.glb.clouddn.com/cliptoBoundsNo.png)
No