socket.io-无法加载资源：net :: err_connection_refuse

Question

我正在建立一个论坛，连接后的两个用户可以发布状态然后对他们发表评论。 对于评论，我使用了 socket.io 。

在控制台中，我每隔几秒钟就会收到此错误：

Failed to load resource: net::ERR_CONNECTION_REFUSED
GET http://localhost/socket.io/?EIO=4&transport=polling&t=O05nump net::ERR_CONNECTION_REFUSED

如何修复此错误？

---

我在我的套接字服务器中安装了 express、nodemon 和 socket.io：

• 套接字服务器：

package.json

{
"name": "socket",
"version": "1.0.0",
"description": "",
"main": "app.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [],
"author": "",
"license": "ISC",
"dependencies": {
  "express": "^4.17.3",
  "nodemon": "^2.0.15",
  "socket.io": "^4.4.1"
  }
}

app.js

const io = require("socket.io")(4000, {
cors: {
    origin: "http//localhost:3000",
},
});


io.on('connection', (socket) => {
  console.log('A new user is connected !');
})
io.on('disconnect', () => {
  console.log('User has left !');
});

---

• Front:

另外，我在客户端安装了 socket.io-client (前面），然后在我的网页中，我添加了以下代码：

import { io } from 'socket.io-client'
export default () => {

  //implement socket
  const socket = useRef()

  useEffect(() => {
      socket.current = io("ws://localhost/4000")
  }, [])

return (
  //some html code
)
}

---

• 我的项目树：

项目论坛

├── back     
├── client
   └──index.jsx
└── socket
   └──package.json
   └──app.js

---

• 控制台 Visual Studio 代码： Visual Studio Code 的控制台仅显示我刷新浏览器或 ctrl+S 代码的次数：

  [nodemon] 启动“node apde app.js”
  

Answer 1

您添加了一个斜线，而不是半彩色：
socket.current = io（“ ws：// localhost：4000”）

Answer 2

const socketio = require("socket.io");
const express = require("express");
const http = require("http");
const app = express();

const PORT = process.env.PORT || 2018;

const server = http.createServer(app);

const io = socketio(server, {
  cors: {
    origin: "*",
    methods: ["GET", "POST", "OPTIONS"]
  }
});

server.listen(PORT, () => {
  io.on("connection", socket => {
    console.log("ok");
    console.log(socket.id);
    // io.in(roomID).emit()
    socket.emit("WELCOME_MESSAGE", ` ${socket.id} welcome!! `);
  });
});