EXPRESS：Router.use() 需要一個中間件函數，但得到了一個對象

Question

每當我嘗試使用app.use()初始化路由時，從我的路由目錄調用我的路由器時出現錯誤。 我得到的錯誤說 Router.use() 需要一個中間件函數，但得到了一個對象。 我讀過這可能是因為我沒有正確導出模塊。 但是我不確定我下面的代碼到底有什么問題。

錯誤：

Users/name/Desktop/personal/app/server/src/node_modules/express/lib/router/index.js:458
      throw new TypeError('Router.use() requires a middleware function but got a ' + gettype(fn))
      ^

TypeError: Router.use() requires a middleware function but got a Object
    at Function.use (/Users/name/Desktop/personal/app/server/src/node_modules/express/lib/router/index.js:458:13)
    at Function.<anonymous> (/Users/name/Desktop/personal/app/server/src/node_modules/express/lib/application.js:220:21)
    at Array.forEach (<anonymous>)
    at Function.use (/Users/name/Desktop/personal/app/server/src/node_modules/express/lib/application.js:217:7)
    at module.exports (/Users/name/Desktop/personal/app/server/src/routes/router.js:18:7)
    at Object.<anonymous> (/Users/name/Desktop/personal/app/server/src/app.js:60:1)
    at Module._compile (module.js:660:30)
    at loader (/Users/name/Desktop/personal/app/server/node_modules/babel-register/lib/node.js:144:5)
    at Object.require.extensions.(anonymous function) [as .js] (/Users/name/Desktop/personal/app/server/node_modules/babel-register/lib/node.js:154:7)
    at Module.load (module.js:573:32)
    at tryModuleLoad (module.js:513:12)
    at Function.Module._load (module.js:505:3)
    at Function.Module.runMain (module.js:701:10)
    at Object.<anonymous> (/Users/name/Desktop/personal/app/server/node_modules/babel-cli/lib/_babel-node.js:154:22)
    at Module._compile (module.js:660:30)
    at Object.Module._extensions..js (module.js:671:10)
[nodemon] app crashed - waiting for file changes before starting...

我的 route.js 文件包含我所有的路由方法。 在 app.js 中：我使用import router from './routes/router'; 然后調用它： router(app);

import express from 'express'
import feed from '../controllers/feed.controller'
import file from '../controllers/file.controller'
import flight from '../controllers/flight.controller'

module.exports = function (app) {

  // Initializing route groups
  const feedRoutes = express.Router(),
    fileRoutes = express.Router(),
    flightRoutes = express.Router(),
    indexRoutes = express.Router();

  //= ========================
  // Feed Routes
  //= ========================//

  app.use('/feeds', feed);

  app.use('/downloads', feed);

  // Find all feeds
  feedRoutes.get('/', feed.list_all_feeds);

  // Find one feed
  feedRoutes.get('/:id', feed.list_one_feed);

  // Find one Audience
  feedRoutes.get('/:id/:audienceId', feed.list_one_feed_audience);

  // Download one Feed
  feedRoutes.get('/:id/download', feed.download_one_feed);

  //= ========================
  // File Routes
  //= ========================//

  app.use('/files', file);

  // Find all files
  fileRoutes.get('/', file.list_all_files);

  // Find one file
  fileRoutes.get('/:id', file.list_one_file);

  //= ========================
  // Flight Routes
  //= ========================//

  app.use('/flights', flight);

  // Find all flights
  flightRoutes.get('/', flight.list_all_flights);

  // Find one flight
  flightRoutes.get('/:id', flight.list_one_flight);

  //= ========================
  // Index Routes
  //= ========================//

  app.use('/', index);

  // Set Main index Route
  indexRoutes.get('/', function(req, res, next) { res.render('index', { title: 'Express', layout: 'layout.hbs' }) });
}

Answer 1

錯誤給出了詳細信息

at module.exports (/Users/name/Desktop/personal/app/server/src/routes/router.js:18:7)

app.use('/feeds', feed);

這里的feed是一個對象而不是一個函數

Answer 2

useCreateIndex: true 連接到您提供 url 的 mongodb 時