Flask socketio服务器+React socket.ioclient连接被拒绝

Question

我无法从React前端连接到python后端

这就是错误所在

polling-xhr.js:268 GET http://localhost:5000/socket.io/?EIO=3&transport=polling&t=NEzs39W net::ERR_CONNECTION_REFUSED

前端侧代码（正在收听）http://localhost:3000 ):

import React from 'react';
import { render } from 'react-dom';
import io from "socket.io-client";

class App extends React.Component {

   constructor(props) {
       super(props);

       const socket = io('http://localhost:5000');

       socket.on('connect', (error) => {
           console.log(error);
       });
   }

   render() {
       return <h1>Hi!</h1>
   }
};

render(
   <App />,
   document.getElementById('root')
);

后端端代码：

from flask_cors import CORS
from flask_socketio import SocketIO, emit

app = Flask(__name__)
cors = CORS(app, resources={r"/*":{"origins":"*"}})
socket = SocketIO(app)

if __name__ == '__main__':
    socket.run(app, host='0.0.0.0', port=5000)

我的代码怎么了？ 多谢各位

Answer 1

此处不应将任何变量分配给CORS：

cors = CORS(app, resources={r"/*":{"origins":"*"}})

相反，请尝试使用：

 CORS(app, resources={r"/*":{"origins":"*"}})