Clienci

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Net;
using System.Net.Sockets;
using System.IO;
using System.ComponentModel;
using System.Windows.Threading;
using System.Threading;
using System.Windows.Controls.Primitives;

namespace yt_tutek_chyba_good
{
    public partial class MainWindow : Window
    {
        private TcpClient client;
        private StreamReader STR;
        private StreamWriter STW;
        private string received;
        private String text_to_send;
        public BackgroundWorker worker1;
        public BackgroundWorker worker2;


        public MainWindow()
        {
            InitializeComponent();
            worker1 = new BackgroundWorker();
            worker1.DoWork += backgroundWorker1_DoWork;

            worker2 = new BackgroundWorker();
            worker2.DoWork += backgroundWorker2_DoWork;
        }

        private void buttonStartServer_Click(object sender, RoutedEventArgs e)
        {
            TcpListener listener = new TcpListener(IPAddress.Any, int.Parse(textBoxPortServer.Text));
            listener.Start();
            client = listener.AcceptTcpClient();
            STR = new StreamReader(client.GetStream());
            STW = new StreamWriter(client.GetStream());
            STW.AutoFlush = true;

            worker1.RunWorkerAsync();
            worker2.WorkerSupportsCancellation = true;
        }


        private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e)
        {
            while (client.Connected)
            {
                try
                {
                    received = STR.ReadLine();
                    this.textBoxConversation.Dispatcher.Invoke(DispatcherPriority.Normal, (ThreadStart)delegate () { textBoxConversation.AppendText("You: " + received + "\n"); });
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }
        private void backgroundWorker2_DoWork(object sender, DoWorkEventArgs e)
        {
            if (client.Connected)
            {
                STW.WriteLine(text_to_send);
                this.textBoxConversation.Dispatcher.Invoke(DispatcherPriority.Normal, (ThreadStart)delegate () { textBoxConversation.AppendText("Me: " + text_to_send + "\n"); });
            }
            else
            {
                MessageBox.Show("send failed !");
            }
            worker2.CancelAsync();
        }

        private void buttonConnect_Click(object sender, RoutedEventArgs e)
        {
            client = new TcpClient();
            IPEndPoint IP_End = new IPEndPoint(IPAddress.Parse(textBoxIPClient.Text), int.Parse(textBoxPortClient.Text));

            try
            {
                client.Connect(IP_End);
                if (client.Connected)
                {
                    textBoxConversation.AppendText("Connected to server" + "\n");
                    STR = new StreamReader(client.GetStream());
                    STW = new StreamWriter(client.GetStream());
                    STW.AutoFlush = true;

                    worker1.RunWorkerAsync();

                    worker2.WorkerSupportsCancellation = true;

                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }

        }
        private void buttonSend_Click(object sender, RoutedEventArgs e)
        {
            if (textBoxMessage.Text != "")
            {
                text_to_send = textBoxMessage.Text;
                worker2.RunWorkerAsync();
            }
            textBoxMessage.Text = "";
        }
    }


}