TypeError：upload.single不是一个函数

一个函数"/>

TypeError：upload.single不是一个函数

我已经使用multer在node.js中上传文件，但是当我设置服务器时，出现此错误。TypeError：upload.single不是函数

这是我的server.js

const express=require('express');
const cors=require('cors');
const mongoose=require('mongoose');
const path = require('path');
const router = require('express').Router();
const multer = require('multer');
const upload = multer({dest:'images/'});


require('dotenv').config();

const app= express();
const port=process.env.PORT || 5000;

app.use(cors());
app.use(express.json());


//open connection to the database using Connection String used as an environment Variable
const uri = process.env.STORE_URI;
mongoose.connect(uri,{useNewUrlParser:true,useCreateIndex:true});


const connection=mongoose.connection;
connection.once('open',()=>{
console.log("MongoDB for Store connected successfully");
})
//

//Using the Routes for the Project in the Server
const productsRouter = require('./routes/Products.route');


app.use('/api/products',productsRouter);


if(process.env.NODE_ENV === 'production'){
app.use(express.static('client/build'));

  app.get('*', (req,res)=>{
    res.sendFile(path.resolve(__dirname, 'client', 'build', 'index.html'));
  })
}

app.listen(port,()=>{
 console.log(`Server is runnig on port: ${port}`);
})

module.exports = upload;

这是我在服务器中使用的我的productsRou​​te.js

const router = require('express').Router();
let Product = require('../models/product.model');
let upload = require('../server')

router.route('/add').post(upload.single('productImage'),(req,res)=>{

console.log(req.file);

const productname = req.body.productname;
const description = req.body.description;
const gender = req.body.gender;
const category = req.body.category;
const size = req.body.size;
const price = Number(req.body.price);
const quantity = Number(req.body.quantity);

const newProduct = new Product({
    productname,
    description,
    gender,
    category,
    size,
    price,
    quantity

})

newProduct.save()
    .then(()=>res.json("Product Added!"))
    .catch(err=>res.status(400).json('Err:'+err))
})

有人可以告诉我我在哪里犯了错误，以及对此问题的解决方案。在此先感谢！

我测试您的代码，您应该在module.exports = upload;之前添加以下代码行：const productsRouter = require('./productsRoute');，并将module.exports = router;添加到productsRou​​te.js：

server.js：

const express=require('express');
const cors=require('cors');
const path = require('path');
const router = require('express').Router();
const multer = require('multer');
const upload = multer({dest:'images/'});


//require('dotenv').config();

const app= express();
const port=process.env.PORT || 5000;

app.use(cors());
app.use(express.json());

/*change this line*/
module.exports = upload;


//Using the Routes for the Project in the Server
const productsRouter = require('./productsRoute');


app.use('/api/products', productsRouter);

app.listen(port,()=>{
 console.log(`Server is runnig on port: ${port}`);
})

productsRou​​te.js：

const router = require('express').Router();
//let Product = require('../models/product.model');
let upload = require('./index')
//const express = require('express');
//const router = new express.Router();

router.route('/add').post(upload.single('productImage'),(req,res)=>{


//router.post("/add", upload.single('productImage'),(req,res)=>{ 

console.log(req.file);

const productname = req.body.productname;
const description = req.body.description;
const gender = req.body.gender;
const category = req.body.category;
const size = req.body.size;
const price = Number(req.body.price);
const quantity = Number(req.body.quantity);

const newProduct = new Product({
    productname,
    description,
    gender,
    category,
    size,
    price,
    quantity

})

});

module.exports = router;