へにょへにょな UDP 受信側窓クラス。

UDPServerForm.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Windows.Forms;


namespace demo.udpserver.app.widgets {


    /// <summary>
    /// 
    /// </summary>
    public partial class UDPServerForm : Form {
        /// <summary>
        /// 
        /// </summary>
        private IPEndPoint remote_endpoint_;



        /// <summary>
        /// 
        /// </summary>
        public UDPServerForm() {
            InitializeComponent();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="ergs"></param>
        private void UDPServerForm_Load(object sender, EventArgs ergs) {
            this.remote_endpoint_ = new IPEndPoint( IPAddress.Any, 0 );
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="ergs"></param>
        private void UDPServerForm_Shown(object sender, EventArgs ergs) {
            backgroundWorker.RunWorkerAsync();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="fcergs"></param>
        private void UDPServerForm_FormClosing(object sender, FormClosingEventArgs fcergs) {
            if ( fcergs.CloseReason == CloseReason.UserClosing ) {
                fcergs.Cancel = true;
                this.Visible = false;
            }
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="ergs"></param>
        private void notifyIcon_DoubleClick(object sender, EventArgs ergs) {
            this.Visible = true;
            if ( this.WindowState == FormWindowState.Minimized ) {
                this.WindowState = FormWindowState.Normal;
            }
            this.Activate();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="ergs"></param>
        private void tsmiNotifyIconQuit_Click(object sender, EventArgs ergs) {
            backgroundWorker.CancelAsync();
            Application.Exit();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="ergs"></param>
        private void backgroundWorker_DoWork(object sender, DoWorkEventArgs dwergs) {
            try {
                UdpClient udp_receiver = new UdpClient( 52292 );
                int report = 0;

                while ( true ) {
                    byte[] received_bytes = udp_receiver.Receive( ref this.remote_endpoint_ );

                    backgroundWorker.ReportProgress( report, Encoding.UTF8.GetString( received_bytes ) );

                    byte[] send_bytes = Encoding.UTF8.GetBytes( "<response><result status=\"200\">OK</result></response>" );
                    udp_receiver.Send( send_bytes, send_bytes.Length, this.remote_endpoint_ );

                    ++report;
                }
            } catch ( SocketException se ) {
                dwergs.Result = se;
                backgroundWorker.CancelAsync();
            }
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="rwcergs"></param>
        private void backgroundWorker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs rwcergs) {
            StringBuilder resulttext_builder = new StringBuilder( tbResult.Text );

            resulttext_builder.AppendLine( rwcergs.Result.ToString() );
            if ( rwcergs.Cancelled ) {
                resulttext_builder.AppendLine( rwcergs.Error.ToString() );
            }

            tbResult.Text = resulttext_builder.ToString();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="pcergs"></param>
        private void backgroundWorker_ProgressChanged(object sender, ProgressChangedEventArgs pcergs) {
            StringBuilder resulttext_builder = new StringBuilder( tbResult.Text );

            resulttext_builder.AppendLine( pcergs.UserState.ToString() );
            
            progressBar.PerformStep();
            tbResult.Text = resulttext_builder.ToString();
        }


    }


}