req.file在控制台中显示为未定义

Question

我正试图从我的网络应用程序在youtube上上传视频，但我在向后端发送文件时遇到错误，它显示req.file在req.body中未定义。它显示videoFile:"未定义的"；以及我能看到的所有其他值，但我无法将文件从我的react应用程序获取到后端。

输入.jsx

import axios from "axios";
import React, { useState } from "react";
// import Axios from "axios";
function Input() {
const [form, setForm] = useState({
title: "",
description: "",
file: null,
});
function handleChange(event) {
const InputValue =
event.target.name === "file" ? event.target.file : event.target.value;
setForm({
...form,
[event.target.name]: InputValue,
});
}
function handleSubmit(event) {
event.preventDefault();
console.log({ form });
const headers = {
"content-type": "multipart/form-data",
};
const videoData = new FormData();
videoData.append("videoFile", form.file);
videoData.append("title", form.title);
videoData.append("description", form.description);
axios
.post("http://localhost:3001/upload", videoData, { headers })
.then((res) => {
console.log(res.data);
})
.catch((err) => console.log(err));
}
return (
<div className="form">
<h1>
<i className="fab fa-youtube"></i> Upload video
</h1>
<form onSubmit={handleSubmit} method="POST" enctype="multipart/form-data">
<div>
<input
className="title"
type="text"
placeholder="Title"
name="title"
autoComplete="off"
onChange={handleChange}
/>
</div>
<div>
<textarea
typeof="text"
placeholder="description"
name="description"
autoComplete="off"
onChange={handleChange}
/>
</div>
<div>
<input
type="file"
accept="video/mp4,video/x-m4v,video/*"
placeholder="Add"
name="file"
onChange={handleChange}
/>
</div>
<button className="btn btn-light" type="submit">
Upload Video
</button>
</form>
</div>
);
}
export default Input;

这是node.js的一部分App.js(后端(

const express = require("express");
const multer = require("multer");
const youtube = require("youtube-api");
const open = require("open");
const cors = require("cors");
const fs = require("fs");
const credentials = require("./client_secret_1013548512515-lti2tpl88m8qqkum1hh095cnevtdi3lu.apps.googleusercontent.com.json");
const app = express();
const bodyParser = require("body-parser");
app.use(express.json());
app.use(cors());
app.use(bodyParser.urlencoded({ extended: true }));
const storage = multer.diskStorage({
destination: "./",
filename: (req, file, cb) => {
const newFileName = `${Date.now()}-${file.originalname}`;
cb(null, newFileName);
},
});
const uploadVideoFile = multer({
storage: storage,
}).single("videoFile");
app.post("/upload", uploadVideoFile, (req, res) => {
console.log(req.body);
console.log(req.file); //it is showing undefined
if (req.file) { //getting error in this part
const filename = req.file.filename;
const { title, description } = req.body;
open(
oAuth.generateAuthUrl({
access_type: "offline",
scope: "https://www.googleapis.com/auth/youtube.upload",
state: JSON.stringify({
filename,
title,
description,
}),
})
);
}
});
app.get("/oauth2callback", (req, res) => {
res.redirect("http://localhost:3000/success");
const { filename, title, description } = JSON.parse(req.query.state);
oAuth.getToken(req.query.code, (err, tokens) => {
if (err) {
console.log(err);
return;
}
oAuth.setCredentials(tokens);
youtube.videos.insert(
{
resource: {
snippet: { title, description },
status: { privacyStatus: "private" },
},
part: "snippet,status",
media: {
body: fs.createReadStream(filename),
},
},
(err, data) => {
console.log("Done");
process.exit();
}
);
});
});
const oAuth = youtube.authenticate({
type: "oauth",
client_id: credentials.web.client_id,
client_secret: credentials.web.client_secret,
redirect_url: credentials.web.redirect_uris[0],
});
PORT = 3001;
app.listen(PORT, () => {
console.log("app is listening on port 3001");
});

Answer 1

请在Input.jsx文件中进行以下更改。

// 1. Inside the handleChange() function
const InputValue = event.target.name === "file" ? event.target.files : event.target.value;

// 2. Inside the handleSubmit() function
videoData.append("videoFile", form.file[0], form.file[0].name);

这应该输出req.file中的文件对象。