我已经安装了“npm install express”命令。 但仍然收到错误
我可以正常安装npm包，而且我已经安装了“npm install express”命令。 这是试图运行的app.js文件：
/* app.js */ var app = require('express').createServer(); app.get('/', function(req, res){ res.send('hello world'); }); app.listen(3000); c:\> node app.js
这是错误：
node.js:63 throw e; ^ Error: Cannot find module 'express' at loadModule (node.js:275:15) at require (node.js:411:14) at Object.<anonymous> (/home/node/app/app.js:1:73) at Module._compile (node.js:462:23) at Module._loadScriptSync (node.js:469:10) at Module.loadSync (node.js:338:12) at Object.runMain (node.js:522:24) at Array.<anonymous> (node.js:756:12) at EventEmitter._tickCallback (node.js:55:22) at node.js:773:9
问题，我跟随什么错误的步骤？
这是安装express后的输出：
C:\MYSite>npm install express npm http GET https://registry.npmjs.org/express npm http 200 https://registry.npmjs.org/express npm http GET https://registry.npmjs.org/connect/2.7.2 npm http GET https://registry.npmjs.org/commander/0.6.1 npm http GET https://registry.npmjs.org/fresh/0.1.0 npm http GET https://registry.npmjs.org/range-parser/0.0.4 npm http GET https://registry.npmjs.org/methods/0.0.1 npm http GET https://registry.npmjs.org/cookie/0.0.5 npm http GET https://registry.npmjs.org/buffer-crc32/0.1.1 npm http GET https://registry.npmjs.org/debug npm http GET https://registry.npmjs.org/cookie-signature/0.0.1 npm http GET https://registry.npmjs.org/mkdirp/0.3.3 npm http GET https://registry.npmjs.org/send/0.1.0 npm http 304 https://registry.npmjs.org/range-parser/0.0.4 npm http 304 https://registry.npmjs.org/methods/0.0.1 npm WARN package.json methods@0.0.1 No README.md file found! npm http 304 https://registry.npmjs.org/fresh/0.1.0 npm http 200 https://registry.npmjs.org/commander/0.6.1 npm http GET https://registry.npmjs.org/commander/-/commander-0.6.1.tgz npm http 304 https://registry.npmjs.org/cookie/0.0.5 npm http 200 https://registry.npmjs.org/connect/2.7.2 npm http 304 https://registry.npmjs.org/buffer-crc32/0.1.1 npm http GET https://registry.npmjs.org/connect/-/connect-2.7.2.tgz npm http 304 https://registry.npmjs.org/debug npm http 200 https://registry.npmjs.org/cookie-signature/0.0.1 npm http GET https://registry.npmjs.org/cookie-signature/-/cookie-signature-0.0.1.tgz npm http 200 https://registry.npmjs.org/mkdirp/0.3.3 npm http GET https://registry.npmjs.org/mkdirp/-/mkdirp-0.3.3.tgz npm http 304 https://registry.npmjs.org/send/0.1.0 npm http 200 https://registry.npmjs.org/commander/-/commander-0.6.1.tgz npm http 200 https://registry.npmjs.org/connect/-/connect-2.7.2.tgz npm http 200 https://registry.npmjs.org/cookie-signature/-/cookie-signature-0.0.1.tgz npm http 200 https://registry.npmjs.org/mkdirp/-/mkdirp-0.3.3.tgz npm http GET https://registry.npmjs.org/mime/1.2.6 npm http GET https://registry.npmjs.org/pause/0.0.1 npm http GET https://registry.npmjs.org/formidable/1.0.11 npm http GET https://registry.npmjs.org/bytes/0.1.0 npm http GET https://registry.npmjs.org/qs/0.5.1 npm http 304 https://registry.npmjs.org/mime/1.2.6 npm http 304 https://registry.npmjs.org/bytes/0.1.0 npm http 304 https://registry.npmjs.org/pause/0.0.1 npm http 200 https://registry.npmjs.org/qs/0.5.1 npm http GET https://registry.npmjs.org/qs/-/qs-0.5.1.tgz npm http 200 https://registry.npmjs.org/formidable/1.0.11 npm http GET https://registry.npmjs.org/formidable/-/formidable-1.0.11.tgz npm http 200 https://registry.npmjs.org/qs/-/qs-0.5.1.tgz npm http 200 https://registry.npmjs.org/formidable/-/formidable-1.0.11.tgz express@3.1.0 node_modules\express ├── methods@0.0.1 ├── fresh@0.1.0 ├── buffer-crc32@0.1.1 ├── cookie-signature@0.0.1 ├── cookie@0.0.5 ├── range-parser@0.0.4 ├── commander@0.6.1 ├── debug@0.7.2 ├── mkdirp@0.3.3 ├── send@0.1.0 (mime@1.2.6) └── connect@2.7.2 (pause@0.0.1, bytes@0.1.0, formidable@1.0.11, qs@0.5.1)
您在本地安装快递，而不是全球
C：\ MYSite> npm install express
所以你只能从这个MYSite文件夹运行。 但是你从不同的位置运行它。
C：> node app.js
因此，它不断给错误Error: Cannot find module 'express'
即使全局安装，如果你已经使用Homebrew来安装节点，你仍然会有一个问题。
你可以通过以下几点来解决它：
brew uninstall node
然后使用nodejs.org站点上的安装程序安装节点。
然后运行：
npm install -g express
希望这有助于某人。