C＃ - 将WebSocket消息发送到客户端

Question

我按照以下教程在C＃中设置了websocket服务器： https://developer.mozilla.org/pt-BR/docs/WebSockets/Writing_WebSocket_server

在此之后，我写了一个部分，它会解码一个正常的消息并在控制台中显示给我。

现在，我希望能够将此消息发送回客户端（具体是ws：//echo.websocket.org）

这是我的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net.Sockets;
using System.Net;
using System.Text.RegularExpressions;
using System.Security.Cryptography;

using System.Threading.Tasks;

namespace sockecho
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpListener server = new TcpListener(IPAddress.Parse("127.0.0.1"), 80);

            server.Start();
            Console.WriteLine("Server has started on 127.0.0.1:80.{0}Waiting for a connection...", Environment.NewLine);
            TcpClient client = server.AcceptTcpClient();
            Console.WriteLine("A client connected.");
            NetworkStream stream = client.GetStream();

            //enter to an infinite cycle to be able to handle every change in stream
            while (true)
            {

                while (!stream.DataAvailable) ;
                Byte[] bytes = new Byte[client.Available];
                stream.Read(bytes, 0, bytes.Length);
                //translate bytes of request to string
                String data = Encoding.UTF8.GetString(bytes);
                if (new Regex("^GET").IsMatch(data))
                {
                    #region startdata
                    Byte[] response = Encoding.UTF8.GetBytes("HTTP/1.1 101 Switching Protocols" + Environment.NewLine + "Connection: Upgrade" + Environment.NewLine + "Upgrade: websocket" + Environment.NewLine + "Sec-WebSocket-Accept: " + Convert.ToBase64String(
            SHA1.Create().ComputeHash(
                Encoding.UTF8.GetBytes(
                    new Regex("Sec-WebSocket-Key: (.*)").Match(data).Groups[1].Value.Trim() + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
                )
            )
        ) + Environment.NewLine
        + Environment.NewLine);

                    stream.Write(response, 0, response.Length);

                    string responsel = Encoding.UTF8.GetString(response);
                    Console.WriteLine(responsel);
                    #endregion
                }
                else
                {
                    //stream.Write(bytes, 0, bytes.Length);
                    string decodedmessage = GetMessage(bytes);
                    Console.WriteLine(decodedmessage);

                    byte[] toBytes = Encoding.ASCII.GetBytes(decodedmessage);
                    stream.Write(toBytes, 0, toBytes.Length);

                }

            }


        }

        private static string GetMessage (Byte[] bytes)
        {
            string DETEXT = "";
            if (bytes[0] == 129)
            {
                int position = 0;
                int Type = 0;
                ulong length = 0;
                if (bytes[1] - 128 >= 0 && bytes[1] - 128 <= 125)
                {
                    length = (ulong)bytes[1] - 128;
                    position = 2;
                }
                else if (bytes[1] - 128 == 126)
                {
                    Type = 1;
                    length = (ulong)256 * bytes[2] + bytes[3];
                    position = 4;
                }
                else if (bytes[1] - 128 == 127)
                {
                    Type = 2;
                    for (int i = 0; i < 8; i++)
                    {
                        ulong pow = Convert.ToUInt64(Math.Pow(256, (7 - i)));
                        length = length + bytes[2 + i] * pow;
                        position = 10;
                    }
                }
                else
                {
                    Type = 3;
                    Console.WriteLine("error 1");
                }

                if (Type < 3)
                {
                    Byte[] key = new Byte[4] { bytes[position], bytes[position + 1], bytes[position + 2], bytes[position + 3] };
                    Byte[] decoded = new Byte[bytes.Length - (4 + position)];
                    Byte[] encoded = new Byte[bytes.Length - (4 + position)];

                    for (long i = 0; i < bytes.Length - (4 + position); i++) encoded[i] = bytes[i + position + 4];

                    for (int i = 0; i < encoded.Length; i++) decoded[i] = (Byte)(encoded[i] ^ key[i % 4]);

                    DETEXT = Encoding.UTF8.GetString(decoded);
                }
            }
            else
            {
                Console.WriteLine("error 2: " + bytes[0].ToString());
            }
            return DETEXT;
        }
    }
}