Unity WebGL using Websockets can't get message from server

Unity Engine
1

I 'am following this guide to build a WebGL project with WebSockets.

In Editor, it is worked. The client can send and receive message from server. However, build on WebGL is not working. The client can send message to server but can’t receive message from server. Any step I miss? Or anyone can help me? Thanks.

Sever code:

using System;
using WebSocketSharp;
using WebSocketSharp.Server;
using System.Security.Cryptography.X509Certificates;

namespace Example
{
   public class Echo : WebSocketBehavior
   {
       protected override void OnMessage(MessageEventArgs e)
       {
           var msg = System.Text.Encoding.UTF8.GetString(e.RawData);
           Console.WriteLine("Got Message: " + msg);
           Send(msg);
       }
   }

  public class Program
  {
   public static void Main (string[] args)
   {
     var wssv = new WebSocketServer (9000, true);

     wssv.SslConfiguration.ServerCertificate =
     new X509Certificate2 ("cert.pfx");

     wssv.AddWebSocketService<Echo> ("/echo");
     wssv.Start ();
     Console.Read();
     wssv.Stop ();
   }
  }
}

Client code in Unity:

using System.Collections;
using System.Collections.Generic;
using System.Text;
using UnityEngine;

// Use plugin namespace
using HybridWebSocket;

public class WebSocketDemo : MonoBehaviour {

    // Use this for initialization
    void Start () {

        // Create WebSocket instance
        WebSocket ws = WebSocketFactory.CreateInstance("ws://localhost:9000/echo");

        // Add OnOpen event listener
        ws.OnOpen += () =>
        {
            Debug.Log("WS connected!");
            Debug.Log("WS state: " + ws.GetState().ToString());

            ws.Send(Encoding.UTF8.GetBytes("Hello from Unity 3D!"));
        };

        // Add OnMessage event listener
        ws.OnMessage += (byte[] msg) =>
        {
            Debug.Log("WS received message: " + Encoding.UTF8.GetString(msg));

            ws.Close();
        };

        // Add OnError event listener
        ws.OnError += (string errMsg) =>
        {
            Debug.Log("WS error: " + errMsg);
        };

        // Add OnClose event listener
        ws.OnClose += (WebSocketCloseCode code) =>
        {
            Debug.Log("WS closed with code: " + code.ToString());
        };

        // Connect to the server
        ws.Connect();

    }
   
    // Update is called once per frame
    void Update () {
       
    }
}
2

Hmm, try contacting the author of that project - at GitHub - jirihybek/unity-websocket-webgl: Hybrid WebSocket implementation for Unity 3D with support of native and browser client. ?

3

Have you found any solution to this? I’m having the same problem

4

The solution is that in WebSocket.jslib, in the instance.ws.onmessage = function(ev), the if statement
if (ev.data instanceof ArrayBuffer)
only reats ArrayBuffers (binary data), but you are sending a string. So you need to add
else if(typeof ev.data === “string”)
and then send the webSocketState.onMessage with that string as the argument.
I have not yet been able to convert ev.data to a string an pass it to onMessage, but I have to continue searching… If anyone know, please help. This is what I have:

       else if(typeof ev.data === "string")
           {
               var msgBytes = lengthBytesUTF8(ev.data) + 1;
               var msgBuffer = _malloc(msgBytes);
               stringToUTF8(ev.data, msgBuffer, msgBytes);
               try {
                   Module['dynCall_viii'](webSocketState.onMessage, instanceId, msgBuffer, msgBytes);
               } finally {
                   _free(buffer);
               }
           }
5

I ended up changing all the OnMessage functions to be like the OnError function, which takes a string instead of bytes[ ]