npm 在创建反应应用程序后在 cmd 上启动总是给出错误

Question

我创建了一个简单的 React 应用程序并成功了，因为它已经在 cmd 上显示了快乐的黑客消息，但是当我在 cmd 上键入并运行“npm start”时，它给出了很多错误。 我已经尝试卸载然后安装节点和 npm 几次，但它仍然无法正常工作。 这是错误消息

Creating a new React app in C:\myapp2.

Installing packages. This might take a couple of minutes.
Installing react, react-dom, and react-scripts...


> core-js@2.6.10 postinstall C:\myapp2\node_modules\babel-runtime\node_modules\core-js
> node postinstall || echo "ignore"


> core-js@3.2.1 postinstall C:\myapp2\node_modules\core-js
> node scripts/postinstall || echo "ignore"

+ react-dom@16.11.0
+ react@16.11.0
+ react-scripts@3.2.0
added 1475 packages from 693 contributors and audited 904933 packages in 828.526s
found 0 vulnerabilities


Success! Created myapp2 at C:\myapp2
Starting the development server...

events.js:187
      throw er; // Unhandled 'error' event
      ^

Error: spawn cmd ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:264:19)
    at onErrorNT (internal/child_process.js:456:16)
    at processTicksAndRejections (internal/process/task_queues.js:80:21)
Emitted 'error' event on ChildProcess instance at:
    at Process.ChildProcess._handle.onexit (internal/child_process.js:270:12)
    at onErrorNT (internal/child_process.js:456:16)
    at processTicksAndRejections (internal/process/task_queues.js:80:21) {
  errno: 'ENOENT',
  code: 'ENOENT',
  syscall: 'spawn cmd',
  path: 'cmd',
  spawnargs: [ '/c', 'start', '""', '/b', 'http://localhost:3000/' ]
}
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! myapp2@0.1.0 start: `react-scripts start`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the myapp2@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\ASUS\AppData\Roaming\npm-cache\_logs\2019-11-13T21_57_29_371Z-debug.log

我希望你们能帮助我指出我应该在哪里进行更改，以便它能够成功运行。 提前致谢 ！

Answer 1

使用 create-react-app 创建项目后

create-react-app name

你必须在创建的文件夹中 go

cd name

然后运行

npm start

再次

Answer 2

首先在一个驱动器（D：或E：）中创建一个文件夹，在命令提示符下打开它并创建一个反应应用程序，如：

npm create-react-app 项目名称

或者

npx-create-react-app 项目名称 cd 项目名称 npm start