Question

我正在使用Node，Express和Handlebars创建一个应用程序，并使用multer上传图像。每次提交表单时，req.file都是未定义的。我花了一整天的时间进行故障排除，但无法弄清楚我做错了什么。

路由器文件：

const express = require('express');
const router = express.Router();
const multer = require('multer');
const mongoose = require('mongoose');
const path = require('path');
const methodOverride = require('method-override');


//Set Storage Engine
const storage = multer.diskStorage({
    destination: './public/uploads/images',
    filename: function (req, file, cb) {
        cb(null, file.fieldname + '-' + Date.now() + 
    path.extname(file.originalname));
    }
});

const upload = multer({
    storage: storage
}).single('featuredImage');

//Change Featured Image - POST
router.post('/saveImage/:id', (req, res) => {
    console.log(req.file);

    //removed the rest of the code to keep it simple. req.file here is always undefined.

});

表格

<form action="/saveImage/{{pitch.id}}" method="POST" enctype="multipart/form-data">

    <div class="form-group">
        <label for="featuredImage">Featured Image</label>
         <input type="file" name="featuredImage" id="featuredImage">
     </div>

     <input type="submit" value="SAVE">
</form>

app.js 这些要求位于app.js文件中。

const express = require('express');
const exphbs  = require('express-handlebars');
const path = require('path');
const passport = require('passport');
const mongoose = require('mongoose'); 
const bodyParser = require('body-parser');
const flash = require('connect-flash');
const session = require('express-session');
const methodOverride = require('method-override');
const nodemailer = require('nodemailer');

//Set StaticFolder
app.use(express.static(path.join(__dirname, 'public')));

Answer 1

您需要添加upload.single('featuredImage')作为相应路由的中间件，如下所示。

const upload = multer({storage: storage});

//Change Featured Image - POST
router.post('/saveImage/:id',upload.single('featuredImage'), (req, res) => {
    console.log(req.file);

   //removed the rest of the code to keep it simple. req.file here is always undefined.

});

Answer 2

请参阅这个问题。它有你正在寻找的答案。

node js multer file upload not working. req.file and req.files always undefined

Answer 3

使用此：

var fileupload = require("express-fileupload");
app.use(fileupload());

Answer 4

就我而言，这是图像大小的问题。我通过如下定义 multer limit 解决了这个问题：

const upload = multer({ storage: storage, limits: { fieldSize: 10 * 1024 * 1024 } }); //10MB

我花了很长时间才弄明白。也许这可以帮助某人

multer - req.file未定义。

4 个答案: