Websocket client not connecting to websocket server

Question

I have a NET Core 3.1 API in which I create a websocket server and start it when the API runs

Program.cs class in API:

using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
using System;
using System.IO;
using WebSocketSharp;
using WebSocketSharp.Server;

namespace aspnetcore_api_server
{
    public class Program
    {
        public class ServerData : WebSocketBehavior
        {
            protected override void OnMessage(MessageEventArgs e)
            {
                Console.WriteLine("WS Status: Received message from client: " + e.Data);
                Send(e.Data);
            }
        }

        public static void Main(string[] args)
        {
            var wssv = new WebSocketServer("ws://127.0.0.1:1234");

            wssv.Start();

            Console.WriteLine("WS Server started on ws://127.0.0.1:1234");

            Console.ReadKey();
            wssv.Stop();
        }
    }
}

Then I have a ASP NET MVC web app from which I'm trying to start a connection with the server:

using System;
using WebSocketSharp;

namespace aspnet_client
{
    public class WebSocketService
    {
        public WebSocketService()
        {
        }

        public void StartConnection()
        {
            using (WebSocket ws = new WebSocket("ws://127.0.0.1:1234"))
            {
                ws.Connect();
                ws.Send("Hello from client ASP NET web app!");              
            }
        }

        private static void Ws_OnMessage(object sender, MessageEventArgs e)
        {
            Console.WriteLine("Receiveed from the server: " + e.Data);
        }
    }
}

When I try to send the message to the server by doing ws.Send from the client, it throws an error stating: System.InvalidOperationException: 'The current state of the connection is not Open.'

In the CMD I am running a command netstat -aon and I can clearly see that the TCP port is open and listening (see attached image).

I'm using WebSocketSharp on both sides Client and Server.

Can someone throw some light about what I could be doing wrong or missing here?

Answer 1

it looks like you might want to add the service

on the server side

wssv.AddWebSocketService<ServerData >("/ServerData");

on the client side your url will want to have /ServerData at the end