Xcode问题与技巧

1、could not start debugserver on...

Restart Xcode and the device[图片上传中...(image.png-519709-1514011547144-0)]

2、出现警告This application is modifying the autolayout engine from a back..

//说明在子线程中执行UI操作了
// 解决方法
dispatch_async(dispatch_get_main_queue()){
   //code (update UI)                           
} 

定位问题:

image.png