javascript - 我该如何修复 "app.use() requires a middleware function"

Question

所以根据底部的错误信息，问题出现在第11行，也就是我给multer一些参数的地方。因为看起来应该不会有任何问题，我最初认为 multer 没有正确安装，但所有 multer 文件(我相信)都在 node_modules 下。现在我不知道问题出在哪里。

var express = require('express');
var app = express();
var fs = require('fs');

var multer = require('multer');
var bodyParser = require('body-parser');


app.use(express.static('public'));
app.use(bodyParser.urlencoded({ extended: false }));
app.use(multer({ dest: '/tmp/'  }));

app.get('/index.html', function (req, res) {
   res.sendFile( __dirname + "/" + "index.html" );
})

app.post('/file_upload', function (req, res) {
    console.log(req.files.file.name);
   console.log(req.files.file.path);
   console.log(req.files.file.type);
   var file = __dirname + "/" + req.files.file.name;

   fs.readFile( req.files.file.path, function (err, data) {
      fs.writeFile(file, data, function (err) {
         if( err ) {
            console.log( err );
            } else {
               response = {
                  message:'File uploaded successfully',
                  filename:req.files.file.name
               };
            }

         console.log( response );
         res.end( JSON.stringify( response ) );
      });
   });    
})

var server = app.listen(8080, function () {
   var host = server.address().address
   var port = server.address().port

   console.log("Post app listening to://%s:%s", host, port)
})

TypeError: app.use() requires a middleware function
    at EventEmitter.use (/home/asgeir/nodejs/first_test_app/node_modules/express/lib/application.js:210:11)
    at Object.<anonymous> (/home/asgeir/nodejs/first_test_app/server.js:11:5)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
    at Function.Module._load (module.js:301:12)
    at Object.<anonymous> (/usr/local/lib/node_modules/pm2/lib/ProcessContainerFork.js:27:21)
    at Module._compile (module.js:410:26)
    at Object.Module._extensions..js (module.js:417:10)
    at Module.load (module.js:344:32)
/home/asgeir/nodejs/first_test_app/node_modules/express/lib/application.js:210
    throw new TypeError('app.use() requires a middleware function')
    ^

Answer 1

尝试

using app.use(multer({dest: '/tmp/'}).any());

请引用这个问题https://stackoverflow.com/a/36020740/2558788