记录一下早上遇到的错误，代码运行昨晚明明没问题的，早上就报了这个错误
Could not build the precompiled application for the device.
It appears that your application still contains the default signing identifier.
Try replacing 'com.example' with your signing id in Xcode:
open ios/Runner.xcworkspace
用xcode也能直接运行项目，排查了半天原来是手机重新插拔一下就ok了， 哎怪自己菜
