Client

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
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.Sockets;
using System.Net;
using System.ComponentModel;

namespace ViewMySclient
{
    /// <summary>
    /// Interaktionslogik für MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        //##############
        BackgroundWorker bw = new BackgroundWorker();
        BackgroundWorker bw2 = new BackgroundWorker();
        IPHostEntry Host = Dns.GetHostEntry(Dns.GetHostName());
        bool ipset = false;
        //##############



        private void button1_Click(object sender, RoutedEventArgs e)
        {
            try
            {
                if (this.textBox2.Text == "")
                {
                    MessageBox.Show("No Broadcast address!");
                    return;
                }
                WorkStart();
                BroadCastSend();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error" + Environment.NewLine + Environment.NewLine + ex + Environment.NewLine + Environment.NewLine, "Error!");
            }
        }

        public void BroadCastSend()
        {
            try
            {
                string TextBoxer = "";
                string IPBoxer = "";
                Dispatcher.Invoke(new Action(() => TextBoxer = this.textBox1.Text));
                Dispatcher.Invoke(new Action(() => IPBoxer = this.textBox2.Text));
                if (ipset == true)
                {
                    TextBoxer = "ip " + textBox3.Text;
                    ipset = false;
                }
                string myIP = Convert.ToString(Host.AddressList[1]);

                byte[] myWriteBuffer = Encoding.ASCII.GetBytes(TextBoxer);
                //Socket definieren
                Socket bcSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

                //EndPoint definieren bzw. Ziel des Broadcastes
                IPEndPoint iep1 = new IPEndPoint(IPAddress.Parse(IPBoxer), 24710);

                //Optionen auf den Socket binden
                bcSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Broadcast, 1);

                //Broadcast senden
                bcSocket.SendTo(myWriteBuffer, iep1);

                //Socket schliessen, nach erfolgreichem Senden des Broadcastes
                bcSocket.Close();
                bcSocket.Dispose();
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error!" + Environment.NewLine + Environment.NewLine + ex);
                return;
            }
        }

        private void WorkStart()
        {
            bw.DoWork += new DoWorkEventHandler(bw_DoWork);
            bw.RunWorkerAsync();
        }

        private void bw_DoWork(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            bw.WorkerSupportsCancellation = true;
            BroadCastSend();

        }



        private void textBox1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {


                button1_Click(this, new RoutedEventArgs());

            }
        }


        private void WorkStart2()
        {
            try
            {
                bw2.DoWork += new DoWorkEventHandler(bw_DoWork2);
                bw2.RunWorkerAsync();
            }
            catch (Exception)
            {
                return;  //Damit bei mehrfachem klicken keine Fehlermeldung auftritt.
            }
        }


        private void bw_DoWork2(object sender, DoWorkEventArgs e)
        {
            BackgroundWorker worker = sender as BackgroundWorker;
            bw2.WorkerSupportsCancellation = true;
            Receive();

        }

        public void Receive()
        {
            try
            {
                Socket sock = new Socket(AddressFamily.InterNetwork,
                           SocketType.Dgram, ProtocolType.Udp);
                IPEndPoint iep = new IPEndPoint(IPAddress.Any, 24711);
                sock.Bind(iep);
                EndPoint ep = (EndPoint)iep;

                byte[] data = new byte[1024];
                int recv = sock.ReceiveFrom(data, ref ep);
                string stringData = Encoding.ASCII.GetString(data, 0, recv);

                data = new byte[1024];
                recv = sock.ReceiveFrom(data, ref ep);
                stringData = Encoding.ASCII.GetString(data, 0, recv);
                Dispatcher.Invoke(new Action(() => this.listBox1.Items.Add(stringData)));
                sock.Close();
                sock.Dispose();
                Receive();
                // return;
            }
            catch (Exception ex)
            {
                MessageBox.Show("Error" + Environment.NewLine + Environment.NewLine + ex);
            }

        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            WorkStart2();
        }

        private void button2_Click(object sender, RoutedEventArgs e)
        {
            if (this.textBox3.IsEnabled == true)
            {
                this.textBox3.IsEnabled = false;
                ipset = true;
                BroadCastSend();
                return;
            }
            this.textBox3.IsEnabled = true;
            ipset = false;

        }

        private void textBox1_KeyDown_1(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Enter)
            {


                button1_Click(this, new RoutedEventArgs());

            }
        }



    }
}