一、错误提示
今天在开发的时候遇到一个崩溃问题，“This application is modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes. This will cause an exception in a future release.”如图所示
二、错误写法
先来看一下代码的写法，如图所示：
三、错误原因
四、解决方法
iOS之崩溃处理：This application is modifying the autolayout engine from a background thread
原文：http://www.cnblogs.com/rglmuselily/p/6269071.html