为什么在尝试运行新的 React Native 项目时出现错误

Question

I have created a new react native project by running "react-native init MyFirstProject". I have also installed node and have added no code of my own to any of the files.

I have tried to run the project to make sure it works by running "react-native run-ios --simulator="iPhone 8"". The command runs successfully but I am given the following error.

Could not connect to development server.

Ensure the following:

• Node server is running and available on the same.network - run 'npm start' from react-native root
• Node server URL is correctly set in AppDelegate
• WiFi is enabled and connected to the same.network as the Node Server

URL: http://localhost:8081/index.bundle?platform=ios&dev=true&minify=false

RCTFatal __28-[RCTCxxBridge handleError:]_block_invoke

_dispatch_call_block_and_release

_dispatch_client_callout

_dispatch_main_queue_callback_4CF

CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE

__CFRunLoopRun

CFRunLoopRunSpecific Blockquote GSEventRunModal

UIApplicationMain

main

start

How do I fix this error?

Answer 1

Try opening your project ios/MyFirstProject/MyFirstProject.xcworkspace and see if there's any build error.

Answer 2

I ran into this problem too, with the same error:

RCTFatal __28-[RCTCxxBridge handleError:]_block_invoke

It turned out that I had another server running on my local machine on the same port that the expo development client server was running ( :8081 ), and that it was taking priority and then obviously giving the client a very different response to what it was expecting. Quitting the other server fixed the problem.