Error. When the server sends a message or receives a message, the connection is being disrupted.

[hasancaktar]

I am trying to connect a Flutter application to a server that I developed in .NET Core. After establishing the connection, the application disconnects when it receives a message. I have been unable to find a solution. When I connect to the server using Postman, Hercules, or other client applications, there are no issues. However, I cannot establish a connection with this package.

There may be a mismatch during the handshake process. It is possible that the header is not coming correctly due to the parsing structure ("\r\n").

Errors:
[ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: WebSocketChannelException: WebSocketChannelException: HttpException: Invalid request method, uri = http://127.0.0.1:8080

Below is a simple example of the server application and a code snippet for a basic client in Flutter:

Server code:

using XiaoFeng.Net;

namespace AppserverTest
{
    internal class Program
    {
        static NetServer<ServerSession> server8080 = new NetServer<ServerSession>(8080);

        static void Main(string[] args)
        {
            server8080.OnStart += Server8080_OnStart;
            server8080.OnStop += Server8080_OnStop;
            server8080.OnDisconnected += Server8080_OnDisconnected;
            server8080.OnNewConnection += Server8080_OnNewConnection;
            server8080.OnMessage += Server8080_OnMessage;

            server8080.Start();
            Console.ReadLine();
        }

        private static void Server8080_OnStop(ISocket socket, EventArgs e)
        {
            Console.WriteLine("8080 stopped");
        }

        private static void Server8080_OnStart(ISocket socket, EventArgs e)
        {
            Console.WriteLine("8080 started");
        }

        private static void Server8080_OnMessage(INetSession session, string message, EventArgs e)
        {
            Console.WriteLine(message);
            session.Send("Hello");
        }

        private static void Server8080_OnNewConnection(INetSession session, EventArgs e)
        {
            Console.WriteLine("connected: " + session.Headers);
            session.Send("hello");
        }

        private static void Server8080_OnDisconnected(INetSession session, EventArgs e)
        {
            Console.WriteLine("8080 disconnected");
        }
    }
}

Client:

import 'package:web_socket_channel/web_socket_channel.dart';
import 'package:web_socket_channel/status.dart' as status;

main() async {
  final wsUrl = Uri.parse('ws://127.0.0.1:8080')
  var channel = WebSocketChannel.connect(wsUrl);

  channel.stream.listen((message) {
    channel.sink.add('Hi!');
    //channel.sink.close(status.goingAway);
  });
}

Please note that the provided code snippets are for reference purposes, and the issue you are facing may require further analysis and debugging.