關於“Error: listen EADDRINUSE: address already in use 127.0.0.1:3000”

今天在做一個Vue小項目的時候，遇到了這樣一個bug，終端輸入npm run dev指令，本來按照我在package.json文件中配置的命令："dev": "webpack-dev-server --open --port 3000 --hot"，應該會運行webpack工具打包代碼后，自動打開瀏覽器，監聽3000端口，但是此時卻在終端命令行提示出錯，錯誤信息如下：

PS C:\Users\LXD\Desktop\my-vue\vue-cms> npm run dev

01.webpack-study@1.0.0 dev C:\Users\LXD\Desktop\my-vue\vue-cms

webpack-dev-server --open --port 3000 --hot

 

events.js:174
      throw er; // Unhandled 'error' event
      ^

Error: listen EADDRINUSE: address already in use 127.0.0.1:3000
    at Server.setupListenHandle [as listen2] (net.js:1253:19)
    at listenInCluster (net.js:1318:12)
    at GetAddrInfoReqWrap.doListen [as callback] (net.js:1451:7)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:61:10)
Emitted 'error' event at:
    at emitErrorNT (net.js:1297:8)
    at process.tickCallback (internal/process/next_tick.js:63:19)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! 01.webpack-study@1.0.0 dev: webpack-dev-server --open --port 3000 --hot
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the 01.webpack-study@1.0.0 dev 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\LXD\AppData\Roaming\npm-cache_logs\2019-05-23T14_10_58_853Z-debug.log
PS C:\Users\LXD\Desktop\my-vue\vue-cms>

根據錯誤提示，Error: listen EADDRINUSE: address already in use 127.0.0.1:3000，意思是3000端口已經被占用。這時，我尋找的解決方案為：

1. 打開cmd

2. 運行netstat -ano，找到報錯信息提示的端口號那一行，記住最后那個數字

　　3.接下來運行tskill “最后那個數字”，所以這里我運行的是tskill 8408

最后打開VSCode，在終端再次輸入npm run dev，運行成功，問題解決。