问题
I have an app working on a local emulator that is updating live and doing all the things it should be doing.
I also have a physical device connected via USB, and deploying to the device through 'run-android' works successfully, so the bridge is working.
However, the app only shows the default react native welcome screen. Any attempt to update the app results in "Could not connect to development server".
I have tried the suggestions on the screen and they aren't helping. Where do I go next?
回答1:
You probably actually can't talk to the dev server. On an emulator a virtual network with the host PC is automatic, on a real there's no virtual network set up between it and the device. You need to actually have an open port on your desktop for it, and hit the right IP on your physical device, with the wifi network (I'm assuming they're on the same wifi network) set to allow requests to your PC.
Or turn dev support off and include the bundle file in your app. Then you're not going to hotload code, but you have a static version ready to go without a server to talk to.
回答2:
I tried this and it solved my problem.
react-native start --reset-cache
and then
react-native run-android
来源：https://stackoverflow.com/questions/52320806/can-only-update-react-native-on-emulator-not-physical-device