react-native – 为什么npm start会给我一个关于端口的错误？

我输入“npm start”后,我不知道为什么它会给我错误.我正在尝试使用相同的WIFI打开我的React Native项目.我认为这是关于港口的.

这是错误：

Loading dependency graph...events.js:183
  throw er; // Unhandled 'error' event
  ^

Error: listen EADDRINUSE :::8081
    at Server.setupListenHandle [as _listen2] (net.js:1360:14)
    at listenInCluster (net.js:1401:12)
    at Server.listen (net.js:1485:7)
    at D:\rnprojects\testproject\node_modules\metro\src\index.js:156:18
    at new Promise (<anonymous>)
    at Object.<anonymous> 
(D:\rnprojects\testproject\node_modules\metro\src\index.js:155:12)
    at Generator.next (<anonymous>)
at step (D:\rnprojects\testproject\node_modules\metro\src\index.js:47:262)
at D:\rnprojects\testproject\node_modules\metro\src\index.js:47:422
at <anonymous>
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! testproject@0.0.1 start: `node node_modules/react-native/local- 
cli/cli.js start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the testproject@0.0.1 start script.
npm ERR! This is probably not a problem with npm. There is likely additional 
logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\ASUS\AppData\Roaming\npm-cache\_logs\2018-09- 
29T06_20_58_251Z-debug.log

在npm开始后：

可能端口已经在使用中.当我第一次运行react-native run-android然后npm start时,我面临类似的问题.我像这样解决它：
首先,获取在端口8081中运行的进程的id：

sudo lsof -i :8081

然后杀了它：

kill -9 ID_SHOWN_FROM_PREVIOUS_CMD

ID_SHOWN_FROM_PREVIOUS_CMD将类似于25534所以在它之后,先运行npm start然后使用react-native run-android