无法在 node.js 中启动应用程序，出现以下错误答案

【问题标题】：unable to start app in node.js getting the following error无法在 node.js 中启动应用程序，出现以下错误
【发布时间】：2015-08-25 06:16:04
【问题描述】：

欢迎使用 Git（版本 1.9.5-preview20150319）

运行 'git help git' 以显示帮助索引。运行“git help”以显示特定命令的帮助。

$ npm 开始

nodeauth@1.0.0 启动 C:\Users*****\Desktop\nodeauth 节点./bin/www

C:\Users***\Desktop\nodeauth\node_modules\express\lib\application.js:206 throw new TypeError('app.use() 需要中间件函数'); ^

TypeError: app.use() 需要中间件函数在 EventEmitter.use >>...>

//app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var expressValidator = require('express-validator');
var cookieParser = require('cookie-parser');
var session = require('express-session');
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var bodyParser = require('body-parser');
var multer = require('multer');
var flash = require('connect-flash');
var mongo = require('mongodb');
var mongoose = require('mongoose');
var db = mongoose.connection;


var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// Handle File Uploads
app.use(multer({dest:'./uploads'}));

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

//Handle Express Sessions
app.use(session({
  secret:'secret',
  saveUninitialized: true,
  resave:true
}));

// Passport
app.use(passport.initialize());
app.use(passport.session());

// Validator
app.use(expressValidator({
  errorFormatter: function(param, msg, value) {
      var namespace = param.split('.')
      , root    = namespace.shift()
      , formParam = root;

    while(namespace.length) {
      formParam += '[' + namespace.shift() + ']';
    }
    return {
      param : formParam,
      msg   : msg,
      value : value
    };
  }
}));

app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use(flash());
app.use(function (req, res, next) {
  res.locals.messages = require('express-messages')(req, res);
  next();
});

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

【问题讨论】：

你能告诉我们配置app（快递实例）的代码吗？第一个猜测是app.use 调用中的某些内容看起来不像middleware。但如果你没有更具体，我们也不能。
一个简单的登录屏幕，mongodb 在尝试启动应用程序时遇到问题

标签： node.js

【解决方案1】：

您需要以下列形式之一使用app.use(multer({dest:'./uploads/'}))：

app.use(multer({dest:'./uploads/'}).single(...));
app.use(multer({dest:'./uploads/'}).array(...));
app.use(multer({dest:'./uploads/'}).fields(...));

即：

app.use(multer({dest:'./uploads/'}).single('photo'));

并且一定要有类似的东西：

<form action="/postPhotos" enctype="multipart/form-data">
    <input type="file" name="photo">
    <input type="submit" value="Upload photo">
</form>

在您的 html 中。

【讨论】：