Question

在我的应用程序中，我在客户端专用页脚接收来自管理员的消息/通知，我想到使用Web套接字[多套接字]，但是msg只发送回一个套接字，即消息被发送回发送它的同一个套接字，而不是发送到其他套接字，希望附件以简单的方式呈现问题。

注意：所有套接字都响应socket onOpen和onClose，错误在onMessage的响应中！

enter image description here

我的代码是：

server.dart：

import 'dart:io';
import 'package:intl/intl.dart';  // for DateFormat

class myClient {
      WebSocket _socket;

     myClient(WebSocket ws){
            _socket = ws;
            _socket.listen(messageHandler,
                           onError: errorHandler,
                           onDone: finishedHandler);
     }

     void write(String message){ _socket.add(message); }

    void messageHandler(String msg){  
         print('a client sent this msg $msg');
         distributeMessage(msg);
    }

    void errorHandler(error){
         print('one socket got error: $error');
         removeClient(this);
        _socket.close();
    }

    void finishedHandler() {
         print('one socket had been closed');
         distributeMessage('one socket had been closed');
         removeClient(this);
         _socket.close();
    }
}


List<myClient> clients = new List();

 void main() { 
      HttpServer.bind(InternetAddress.ANY_IP_V4, 8080).then((HttpServer server) {
        print("HttpServer listening...");
        server.listen((HttpRequest request) {
          if (WebSocketTransformer.isUpgradeRequest(request)){
              WebSocketTransformer.upgrade(request).then(handleWebSocket);
           }
      else {
            print("Regular ${request.method} request for: ${request.uri.path}");
            serveRequest(request);
            }
        });
     });
 }

void handleWebSocket(WebSocket socket){
  print('Client connected!');
  myClient client = new myClient(socket);
  addClient(client);
}

void serveRequest(HttpRequest request){
  request.response.statusCode = HttpStatus.FORBIDDEN;
  request.response.reasonPhrase = "WebSocket connections only";
  request.response.close();
}

void distributeMessage(String msg){
   var now = new DateTime.now();
   var timeStamp = new DateFormat("[dd-MMM @h:mma]");
   String formatTime = timeStamp.format(now);   
   for (myClient c in clients)c.write('${timeStamp.format(now)}: $msg ');
 }

 void addClient(myClient c){
     clients.add(c);
 }

 void removeClient(myClient c){
      clients.remove(c);
 }

client.dart文件是：

import 'dart:html';

void main() {
       Element fonixFooter = querySelector('#fonix-footer');

       String server = 'ws://localhost:8080/';
       WebSocket ws = new WebSocket(server);
       ws.onOpen.listen((Event e) => fonixFooter.text='Connected to server');   // this is fine

       ws.onMessage.listen((MessageEvent e){        <= this is not functioning!!
          print('msg is: ${e.data}');
          fonixFooter.innerHtml=e.data;
       });

      ws.onClose.listen((Event e) => fonixFooter.text='Connection to server lost...');   // this is fine

   }

admin.dart是：

import 'dart:html';

 void main() {
      TextInputElement input = querySelector('#input');
      ParagraphElement output = querySelector('#output');

      String server = 'ws://localhost:8080/';
      WebSocket ws = new WebSocket(server);
      ws.onOpen.listen((Event e) {
      outputMessage(output, 'Connected to server');
  });

  ws.onMessage.listen((MessageEvent e){
      outputMessage(output, e.data);
  }); 

  ws.onClose.listen((Event e) {
     outputMessage(output, 'Connection to server lost...');
  });

  input.onChange.listen((Event e){
     ws.send(input.value.trim());
     input.value = "";
   });
}

 void outputMessage(Element e, String message){
      print(message);
      e.appendText(message);
      e.appendHtml('<br/>');
      e.scrollTop = e.scrollHeight;
 }

基于@luizmineo的反馈他测试了服务器端，我注意到我的代码工作当且仅当每个套接字发送了一些数据，套接字没有发送数据，没有收到任何东西，但仍然不明白为什么！以及如何解决它！

任何想法，我犯了错误!!任何有关更好方法的建议都表示赞赏。

Answer 1

我通过要求每个套接字在连接时向服务器发送内容来解决它，所以我使用以下代码：

在main.dart和client.dart中，

将onOpen更改为：

ws.onOpen.listen((Event e) => ws.send('Connected to server'));

server.dart中的

将消息处理程序更改为：

  void messageHandler(String msg){  
    if (msg == 'Connected to server')write('Connected to server');   // send msg to the new socket only
    else distributeMessage(msg);  // send msg to all opened sockets
  }

我相信这是一个解决方案，希望听到直接答案！

使用Web套接字[多插槽]在DART lang中从服务器向客户端发送批量/推送消息

1 个答案: