客户端未收到来自套接字js服务器的消息

Question

我正在努力在桌面上的UWP应用程序和Hololens 1之间建立消息通信。

根据Microsoft文档Websocket Implementation的Websockets的实现，我可以使用socket.io Server将信令部分实现到Nodejs

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);

app.get('/', function(req, res){
  res.sendFile(__dirname + '/index.html');
});


var PORT = 3000;
var userId = 0;

http.listen(PORT, function () {
  console.log('listening on *: ' + PORT);
});

io.on('connection', function(socket){
    socket.userId = userId++;
    console.log('a user connected, user id: ' + socket.userId);

    socket.on('mess', function (msg) {
    console.log('message from user#' + socket.userId + ": " + msg);
    // Send message with emit"mess" to all client
    io.emit('mess', msg);
  });

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

两个客户端（uwp app和hololens都可以建立到服务器。在计算机上我可以向服务器发送一些数据。我目前的问题是Hololens没有收到来自服务器的消息。

对于通信部分，我使用了一个包装类，它为2个客户端提供发送和接收功能。这个包装类已生成为dll，以便在2个不同的projekt中引用（uwp app和unity app for hololens）

// Declare "Using" part here...

namespace SocketWrapperNamespace
{

    public delegate void OnReceiveMessengerCallback(string msg);
    public delegate void OnDisconnectCallback(bool connect);

    public class SocketWrapper
    {
        public event OnReceiveMessengerCallback OnReceiveMessenger;
        public event OnDisconnectCallback onDisconnect;

#if !UNITY_EDITOR
        private Uri _uri;
        private MessageWebSocket messageWebSocket;
        private DataWriter dataWriter;
#endif
        // Client can call this function to connect
        public void Connect(string uri)
        {
#if !UNITY_EDITOR
            try
            {
                Connector(uri);
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
#endif
        }

        private async void Connector(string uri)
        {
#if !UNITY_EDITOR
           // Code here look pretty much like in the example from microsoft documentation
#endif
        }

        // Function for client to send message to server
        public void SendMessage(string emiter, string message)
        {
#if !UNITY_EDITOR
            try
            {
                Emit(emiter, message);
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
#endif
        }


        //Emitter
        private async void Emit(string emiter, string message)
        {
#if !UNITY_EDITOR
            try
            {
                if (messageWebSocket == null)
                {
                    return;
                }
                if (dataWriter == null)
                {
                    return;
                }

                string form = string.Format("42[\"{0}\",\"{1}\"]", emiter, message);

                dataWriter.WriteString(form);
                await dataWriter.StoreAsync();
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
#endif
        }

        //Disconnect
        public void Disconnect()
        {
#if !UNITY_EDITOR
          // Disconnecting server ...
#endif
        }

        //Message Arrived Handler
        private void WebSocket_MessageArrived(MessageWebSocket sender, MessageWebSocketMessageReceivedEventArgs args)
        {
#if !UNITY_EDITOR
            try
            {
                if (OnReceiveMessenger == null)
                {
                    return;
                }
                using (DataReader dataReader = args.GetDataReader())
                {
                    if (dataReader != null)
                    {
                        dataReader.UnicodeEncoding = UnicodeEncoding.Utf8;
                        string message = dataReader.ReadString(dataReader.UnconsumedBufferLength);
                        OnReceiveMessenger?.Invoke(message);
                    }
                }
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.Message);
            }
#endif
        }

        //Websocket Close Handler
        private void WebSocket_Closed(IWebSocket sender, WebSocketClosedEventArgs args)
        {
#if !UNITY_EDITOR
            // Close work here ...
#endif
    }
}

在Hololens上，我准备与服务器的连接并收听收到的消息事件。

// hololens client call this method to initialize the connection
public void OnStart()
    {
        socketWrapper = new SocketWrapper();
        uri = String.Concat("ws://",server,":3000/socket.io/?EIO=3&transport=websocket");
#if !UNITY_EDITOR
        socketWrapper.Connect(uri);
        socketWrapper.OnReceiveMessenger += OnMessageArrived_Handler;
        socketWrapper.onDisconnect += OnDisconnect_Handler;
#endif
    }

//Message Arrived Handler
    private void OnMessageArrived_Handler(string msg)
    {
// Here I do not received any message from server
}

我犯了什么错误？我想知道即使我可以从hololens连接到服务器，但订阅部分似乎不起作用？考虑到2个项目位于不同的位置，同样发生在dll上。

我认为我必须将SocketWrapper类设置为Singleton，因为hololens部分实例化了一个新的Object，因此订阅可能无法在这里工作

用其他实现来解决这个问题的任何更好的建议都会有所帮助。

谢谢

Answer 1

我认为现在在C＃和Unity环境中使用WebSocket的最佳解决方案是WebSocketSharp library。它有很好的实施，并保持最新的6年至今。它还有3个如何在不同场景中使用它的例子。