上传空文件时无法读取未定义的属性

我使用Node.js（v0.10.25）和Express（4.13.1）并使用jade而不是HTML。 我有一个registry单，用户可以注册并上传profileimage。

所有工作正常，除非我上传一个空的图像，然后我得到以下错误：

无法读取未定义的属性“profileimage”

APP.JS

var express = require('express'); var path = require('path'); var favicon = require('serve-favicon'); var logger = require('morgan'); var cookieParser = require('cookie-parser'); var bodyParser = require('body-parser'); var session = require('express-session'); var methodOverride = require('method-override'); var passport = require('passport'); var LocalStrategy = require('passport-local').Strategy; var multer = require('multer'); var flash = require('connect-flash'); var expressValidator = require('express-validator'); 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/'}).single('singleInputFileName')); // uncomment after placing your favicon in /public //app.use(favicon(path.join(__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()); //Vallidator 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()); 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; 

user.js的

 var express = require('express'); var router = express.Router(); /* GET users listing. */ router.get('/', function(req, res, next) { res.send('respond with a resource'); }); router.get('/Registreren', function(req, res, next) { res.render('Registration', { title: 'Registreren' }); }); router.get('/Aanmelden', function(req, res, next) { res.render('Aanmelden', { title: 'Aanmelden' }); }); router.post('/Registreren', function(req, res, next){ // Get form value console.log('Bericht in behandeling ...') var username = req.body.username; var email = req.body.email; var password = req.body.password; var password_confirm = req.body.password_confirm; console.log('username: ' + username); console.log('email: ' + email); console.log('password: ' + password); console.log('password_confirm: ' + password_confirm); console.log('FIRST TEST: ' + JSON.stringify(req.files)); console.log('SECOND TEST: ' + req.files.profileimage); // Check for image field if (req.files.profileimage){ console.log('Uploading file....'); //File Info var profileImageOrginalName = req.files.profileimage.orginalname; var profileImageName = req.files.profileimage.name; var profileImageMimetype = req.files.profileimage.mimetype; var profileImagePath = req.files.profileimage.path; var profileImageExt = req.files.profileimage.extension; var profileImageSize = req.files.profileimage.size; } else{ console.log('profileImageFile not found....'); // Set default image var profileImageName = 'noimage.png'; } // Form validation req.checkbody('username','Gebruikersnaam is verplicht').notEmpty(); req.checkbody('email','email is verplicht').notEmpty(); req.checkbody('email','email is niet geldig').isEmail(); req.checkbody('username','Gebruikersnaam is verplicht').notEmpty(); req.checkbody('password','Gebruikersnaam is verplicht').notEmpty(); req.checkbody('password_confirm','Wachtwoorden zijn niet gelijk').equals(req.body.password); req.checkbody('username','Gebruikersnaam is verplicht').notEmpty(); // Error handling console.log('Error handling....'); var errors = req.valdidationErrors(); if (errors){ console.log('Form Errors....'); res.render('Registreren',{ errors: errors, username: username, email: email, password: password, password_confirm: password_confirm }); }else { console.log('No Form Errors....'); var newUser = new User({ username: username, email: email, password: password, profileimage: profileImageName }) // Create User // User.createUser(newUser, function(err,user){ // if(err) throw err; // console.log(user); // }); // Succes message req.flash('succes','Je bent succesvol aangemedld'); res.location('/'); res.redirect('/'); } }); module.exports = router; 

我已阅读和尝试：

1. https://github.com/danialfarid/ng-file-upload/issues/185

2. nodejs和上传文件时表示错误，“不能读取undefined的属性”

3. TypeError：无法读取未定义的属性“图像”

在USER.JS上，第一个testing的结果是“未定义的”，第二个testing的结果是完全失败的。 另外我得到了nog的coole.log中的else语句

 if (req.files.profileimage){ console.log('Uploading file....'); //File Info var profileImageOrginalName = req.files.profileimage.orginalname; var profileImageName = req.files.profileimage.name; var profileImageMimetype = req.files.profileimage.mimetype; var profileImagePath = req.files.profileimage.path; var profileImageExt = req.files.profileimage.extension; var profileImageSize = req.files.profileimage.size; } else{ console.log('profileImageFile not found....'); // Set default image var profileImageName = 'noimage.png'; } 

Answer 1

确保req.files存在，否则会得到未定义的错误。 即：

 if (req.files && req.files.profileImage) { // only if there are files } else { // You should see this now }