multer - req.file 未定义。

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。每次我提交表单时，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.

});

形式

<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这些需要在 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upload.single('featuredImage')为相应的路由添加中间件，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.

});