typeerror:app.use()需要中间件function

我正在使用快速模板引擎学习node.js,我正在遵循udemy课程“通过构build10个项目学习node.js”,而在教授运行npm start localhost:3000时候继续讲课,同时我的popup错误指示了app.use需要中间件function我试过匹配的代码和它一样。 请帮我解决我在这里呆了几个小时的错误尝试了很多编辑,但它不适合我。

当我试图运行“npm start”时popup下面的错误消息

TypeError:app.use()需要中间件function

这里是app.js代码:

 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', saveUninitialied: 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; 

这里是package.json文件

 { "name": "nodeauth", "version": "1.0.0", "private": true, "scripts": { "start": "node ./bin/www" }, "dependencies": { "body-parser": "~1.12.4", "cookie-parser": "~1.3.5", "debug": "~2.2.0", "express": "~4.12.4", "jade": "~1.9.2", "morgan": "~1.5.3", "serve-favicon": "~2.2.1", "mongodb": "*", "mongoose": "*", "connect-flash": "*", "express-validator": "*", "express-session": "*", "express-messages": "*", "passport": "*", "passport-local": "*", "passport-http": "*", "multer": "*" } } 

这里是更新app.js(删除multar后)

 var express = require('express'), path = require('path'), favicon = require('serve-favicon'), logger = require('morgan'), cookieParser = require('cookie-parser'), expressValidator = require('express-validator'), session = require('express-session'), passport = require('passport'), LocalStrategy = require('passport-local').Strategy, bodyParser = require('body-parser'), flash = require('connect-flash'), mongo = require('mongodb'), mongoose = require('mongoose'), db = mongoose.connection, routes = require('./routes/index'), users = require('./routes/users'), app = express(); // view engine setup app.set('views', path.join(__dirname, 'views')); app.set('view engine', 'jade'); // handle file uploads //multer delted // 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: 'keyboard cat', resave: true, saveUninitialized: 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'))); // flash app.use(flash()); // express messages app.use(function(req, res, next) { res.locals.messages = require('express-messages')(req, res); next(); }); app.get('*', function(req, res, next) { res.locals.user = req.user || null; 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: {} }); }); //Express server var http = require('http'); var server = http.createServer(app); app.get('/', function(req, res) { res.send("Hello World!"); }); server.listen(3000, 'localhost'); server.on('listening', function() { console.log('Express server started on port %s at %s', server.address().port, server.address().address); }); module.exports = app; 

谢谢

它以这种方式工作。 删除这一行,

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

并用它作为,

 var multer = require('multer'); var upload = multer({ dest: './uploads' }); 

我也遵循相同的过程

更改:

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

像这样的东西:

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

要么

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

并注意有这样的事情:

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

对于第一种情况,或者:

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

对于第二个,在你的HTML。

这与我工作:

 app.use(multer({ dest: path.join(__dirname, 'public/upload/temp') }).any()); 

我也在这样做,遇到了同样的问题。 我通过遵循他们的github中的Multer使用说明来解决错误: https : //github.com/expressjs/multer

以下是自述文件中的代码:

  var multer = require('multer') var upload = multer({ dest: 'uploads/' }) 

这里是我用来克服错误,而这个教程的代码:

  var multer = require('multer'); var upload = multer({ dest: './uploads' }); 

希望能帮助到你 :)

只改变这一行

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

 var upload =multer({dest:'./uploads'}); 

你可以简单地使用:

 app.set(multer({dest: "./uploads"})); 

它也适用于我。