小编And*_*nes的帖子

因此，我正在开发应用程序，并在模型中添加了一个slugfield。然后，按照正常进行makemigrations，出现了巨大的红色错误墙。

Traceback (most recent call last):
  File "C:\Users\Andreas\ReaderProject\lib\site-packages\django\db\backends\utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "C:\Users\Andreas\ReaderProject\lib\site-packages\django\db\backends\sqlite3\base.py", line 337, in execute
    return Database.Cursor.execute(self, query, params)
sqlite3.OperationalError: no such table: Reader_manga

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Program Files (x86)\JetBrains\PyCharm 2016.2.3\helpers\pycharm\django_manage.py", line 41, in <module>
    run_module(manage_file, None, '__main__', True)
  File "C:\Users\Andreas\AppData\Local\Programs\Python\Python35-32\lib\runpy.py", line 182, in run_module
    return _run_module_code(code, init_globals, run_name, mod_spec)
  File "C:\Users\Andreas\AppData\Local\Programs\Python\Python35-32\lib\runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, …

所以我有这个反应组件，它连接到端口 3000 上的 Express 服务器。 Express 服务器确实工作，并在加载到大厅组件时记录“有人已连接”和“用户已断开连接”。然而，客户端的 on() 位似乎没有做任何事情。我从未收到“已连接到后端”消息来登录客户端控制台。据我所见，我没有收到错误，并且它确实连接到正确的名称空间（来自快速日志）。不知道为什么这不起作用。

import React, { useEffect } from 'react';
import io from 'socket.io-client';
import "./LobbyComponent.css";

function Lobby() {   

    useEffect(() => {
        handleSocket();
    }, []);

    const handleSocket = () => {
        const lobby = io('http://localhost:3000/lobby');
        lobby.on('connection', function (socket){
            console.log('connected to backend');

            socket.on('disconnect', function(){
                console.log('disconnected: ', socket);
            });   

        });  
        lobby.on('chat message', function(msg){
            console.log('message: ', msg);
        });

    };   

    return (
        <div>

        </div>
    )

}

export default Lobby;

服务器.js 文件

let express = require("express");
let app = …