Error: Unexpected field Amazon S3, Express, Multer, MulterS3

Error: Unexpected field Amazon S3, Express, Multer, MulterS3

我收到这个错误，我不知道为什么会给我这个错误，我已经检查了所有与此相关的 tutorials/similar 问题，但没有任何效果。有人可以帮我指明正确的方向吗？

谢谢，

错误：

意外字段

错误：意外字段
在 makeError (C:\Users\Administrator\Desktop\express-cc-master\node_modules\multer\lib\make-error.js:12:13) 在 wrappedFileFilter (C:\Users\Administrator\Desktop\express-cc-master\node_modules\multer\index.js:40:19)

Profile.js

var aws = require('aws-sdk')
var express = require('express');
var router = express.Router();
var multer = require('multer')
var multerS3 = require('multer-s3')

 
aws.config.loadFromPath('./config.json');
aws.config.update({
    signatureVersion: 'v4'
});
 
var s3 = new aws.S3({});

var upload = multer({
  storage: multerS3({
    s3: s3,
    bucket: 'raytestbucket123',
    acl: 'public-read',
    metadata: function (req, file, cb) {
      cb(null, {fieldName: file.fieldname});
    },
    key: function (req, file, cb) {
      cb(null, Date.now()+file.originalname)
    }
  })
})

router.get('/profile', function(req, res){
  res.render('profile', { title: 'Profile' });

});


router.post('/profile', upload.single('file'), function(req, res, next){

  res.send(req.files);
  console.log(req.files);

})


module.exports = router;

Profile.hbs

{{> header }}



  <body> 
    <form action="/profile" method="POST" enctype="multipart/form-data">
      File to upload to S3: 
      <input name="file" type="file"> 
      <br> 
      <input type="submit" value="Upload File to S3"> 
    </form> 
  </body>

<div class="container">
<h2>Profile</h2>
</div>

我自己发现了问题。

而不是

res.send(req.files); console.log(req.files);

应该是

res.send(req.file); console.log(req.file);