Question

我尝试将flutter连接到Express js套接字，但它拒绝了连接或完全没有反应。

我从张量理解了这个示例，但是当我重新加载它时并没有给我任何错误，它告诉我dart：html包丢失了。它与回声 websocket.io 一起工作，但不能与我的后端

一起工作

这是乱码

 import 'package:web_socket_channel/io.dart';
 import 'package:flutter/material.dart';
 import 'package:web_socket_channel/io.dart';
 import 'package:web_socket_channel/web_socket_channel.dart';

 void main()  {
   runApp(MyApp());
 }

 class MyApp extends StatelessWidget {

   @override
   Widget build(BuildContext context) {
     return MaterialApp(
       title: 'Flutter Demo',
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
       home: MyHomePage(title: 'Flutter Demo Home Page'),
     );
   }
 }

 class MyHomePage extends StatefulWidget {
   MyHomePage({Key key, this.title}) : super(key: key);

   final String title;

   @override
   _MyHomePageState createState() => _MyHomePageState();
 }

 class _MyHomePageState extends State<MyHomePage> {
   int _counter = 0;
   WebSocketChannel channel;

   @override
   void initState() {
     super.initState();
     channel = IOWebSocketChannel.connect("ws://mighty-peak-62403.herokuapp.com");
   }

   @override
   void dispose() {
     // TODO: implement dispose
     channel.sink.close();
     super.dispose();
   }

   void _incrementCounter() {
     channel.sink.add("hello world");
   }

   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
         title: Text(widget.title),
       ),
       body: Center(
         child: StreamBuilder(
           stream: channel.stream,
           builder: (context, snapShot) =>
               snapShot.hasData ? Text(snapShot.data) : Text("doenst work"),
         ),
       ),
       floatingActionButton: FloatingActionButton(
         onPressed: _incrementCounter,
         tooltip: 'Increment',
         child: Icon(Icons.add),
       ),
     );
   }
 }

这是后端


    const app = require('express')();
    const server = require('http').Server(app);
    const io = require('socket.io')(server);
    const port = process.env.PORT || 5000

    app.get('/', function(req, res) {
       res.status(200).send("w");
    });

    io.on('connection', (socket) => {
      console.log(`Client SocketID: ${socket.id}.`);
      socket.emit('sayHello', {Hello: 'world!'});
      socket.on('sayHello', (greeting) => {
        console.log(`Hello, ${greeting['Hello']}`);
      });
    });

    server.listen(port,()=>console.log("listening"));

这是从heroku-app上的日志获取的错误

2019-10-24T23：25：39.593874 + 00：00 heroku [router]：at =错误代码= H13 desc =“连接离子关闭，无响应” method = GET path =“ /” host = mighty-peak-62403.herokuap p.com request_id = f9960a12-6f2a-4e6c-9810-fea27d521d51 fwd =“ 156.219.177.165” 强力 = web.1 connect = 0ms服务= 1004ms状态= 503字节= 0协议= http

我希望heroku应用程序能够提供我连接flutter应用程序时实现的日志，但是我却因为错误H13而导致连接断开

无法将颤动与插座连接以表达

0 个答案: