对 React 应用程序使用“npm start 命令”时出现错误答案

【问题标题】：I am getting error while using "npm start command for React application对 React 应用程序使用“npm start 命令”时出现错误
【发布时间】：2020-04-12 15:28:46
【问题描述】：

我是新手，这是我的第一个应用程序。
我已经安装了最新版本的节点 npm/npx。
我使用“create-react-app my-app”创建了一个目录。
之后，当我进入目录并输入“npm start”时，出现以下错误。请帮忙


C:\Users\admin\my-app>npm start

> my-app@0.1.0 start C:\Users\admin\my-app
> react-scripts start

Starting the development server...

events.js:288
     throw er; // Unhandled 'error' event
     ^

Error: spawn cmd ENOENT
←[90m    at Process.ChildProcess._handle.onexit (internal/child_process.js:267:19)←[39m
←[90m    at onErrorNT (internal/child_process.js:469:16)←[39m
←[90m    at processTicksAndRejections (internal/process/task_queues.js:84:21)←[39m
Emitted 'error' event on ChildProcess instance at:
←[90m    at Process.ChildProcess._handle.onexit (internal/child_process.js:273:12)←[39m
←[90m    at onErrorNT (internal/child_process.js:469:16)←[39m
←[90m    at processTicksAndRejections (internal/process/task_queues.js:84:21)←[39m {
 errno: ←[32m'ENOENT'←[39m,
 code: ←[32m'ENOENT'←[39m,
 syscall: ←[32m'spawn cmd'←[39m,
 path: ←[32m'cmd'←[39m,
 spawnargs: [ ←[32m'/s'←[39m, ←[32m'/c'←[39m, ←[32m'start'←[39m, ←[32m'""'←[39m, ←[32m'/b'←[39m, ←[32m'"http://localhost:3000"'←[39m ]
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! my-app@0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the my-app@0.1.0 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\admin\AppData\Roaming\npm-cache\_logs\2020-04-12T15_19_48_491Z-debug.log

这是我的package.json 内容

{
  "name": "my-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.5.0",
    "@testing-library/user-event": "^7.2.1",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-scripts": "3.4.1"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

按照某些人的建议，我删除了我的node modules 文件夹，然后删除了npm update，然后是npm install，但我仍然遇到同样的错误。任何帮助将不胜感激

【问题讨论】：

标签： node.js reactjs react-native npm cmd

【解决方案1】：

我以前见过这个。尝试删除您的node_modules 文件夹，然后运行npm update，然后运行npm install。

如果这不起作用，可以从其他论坛获得一些答案：

一些 Windows 用户表示将 System32 添加到环境变量有帮助：

转到 Control Panel > System 和 Security > System > Advanced system settings > Enviroment variables 并将 系统变量 设置为路径 C:\Windows\System32\ 并重新启动系统。

最坏的情况：将react-scripts 降级到 2.1.8：

npm install react-scripts@2.1.8

【讨论】：