modifying the autolayout engine from a background thread, which can lead to engine corruption and weird crashes
升级iOS9.1、xcode7.1后,iOS也有类似android4.0之后在子线程中不能更新UI的规定了,如果在后台线程中操作UI的话,会提示如下错误:Thisapplicationismodifyingtheautolayoutenginefromabackgroundthread,whichcanleadtoenginecorruptionandweirdcrashes.Thiswillca