iOS - 解决This application is modifying the autolayout engine from a background thread

This application is modifying the autolayout engine from a background thread after the engine was accessed from the main thread. This can lead to engine corruption and weird crashes.

原因

在子线程中进行了对UI控件的操作。比如在子线程下添加了一个UIView，而UI控件的操作都必须在主线程下~

解决方案

回到主线程更新UI

[[NSOperationQueue mainQueue] addOperationWithBlock:^{    // 进行UI控件的操作}];