UDP網路通訊的簡單例子

using System ;
using System.Drawing ;
using System.Collections ;
using System.ComponentModel ;
using System.Windows.Forms ;
using System.Data ;
using System.Net ;
using System.Net.Sockets ;
using System.Threading ;
//程式中使用到線程
using System.Text ;
namespace UDP
{
 /// <summary>
 /// Form1 的摘要說明。
 /// </summary>
 public class Form1 : System.Windows.Forms.Form
 {
  private System.Windows.Forms.Label label1 ;
  private System.Windows.Forms.ListBox listBox1 ;
  private System.Windows.Forms.TextBox textBox1 ;
  private System.Windows.Forms.Label label2 ;
  private System.Windows.Forms.Button button1 ;
  private System.Windows.Forms.Button button2 ;
  private System.Windows.Forms.TextBox textBox2 ;
  private System.Windows.Forms.Label label3 ;
  private System.Windows.Forms.StatusBar statusBar1 ;
  private bool ReadFlag = true ;
  //設定偵聽標示位，通過它來設定是否偵聽連接埠號碼
  private Thread th ;
  //定義一個線程，線上程接收聊天資訊
  private IPEndPoint remote ;
  //定義一個遠程結點，用以擷取遠端電腦IP地址和發送的聊天資訊
  private UdpClient udpclient ;
  //建立一個UDP網路服務
  /// <summary>
  /// 必需的設計器變數。
  /// </summary>
  private System.ComponentModel.Container components = null ;

  public Form1 ( )
  {
   //
   // Windows 表單設計器支援所必需的
   //
   InitializeComponent ( ) ;

   //
   // TODO: 在 InitializeComponent 調用後添加任何建構函式代碼
   //
  }

  /// <summary>
  /// 清理所有正在使用的資源。
  /// </summary>
  protected override void Dispose ( bool disposing )
  {
   /*try
   {
    ReadFlag = false ;
    th.Abort ( ) ;
    remote =null ;
    udpclient.Close ( ) ;
    th = null ;
   }
   catch
   {}*/
   if ( disposing )
   {
    if ( components != null )
    {
     components.Dispose ( ) ;
    }
   }
   base.Dispose ( disposing ) ;
  }

  #region Windows Form Designer generated code
  /// <summary>
  /// 設計器支援所需的方法 - 不要使用代碼編輯器修改
  /// 此方法的內容。
  /// </summary>
  private void InitializeComponent ( )
  {
   this.label1 = new System.Windows.Forms.Label();
   this.listBox1 = new System.Windows.Forms.ListBox();
   this.textBox1 = new System.Windows.Forms.TextBox();
   this.label2 = new System.Windows.Forms.Label();
   this.button1 = new System.Windows.Forms.Button();
   this.button2 = new System.Windows.Forms.Button();
   this.textBox2 = new System.Windows.Forms.TextBox();
   this.label3 = new System.Windows.Forms.Label();
   this.statusBar1 = new System.Windows.Forms.StatusBar();
   this.SuspendLayout();
   //
   // label1
   //
   this.label1.Location = new System.Drawing.Point(11, 6);
   this.label1.Name = "label1";
   this.label1.Size = new System.Drawing.Size(91, 23);
   this.label1.TabIndex = 0;
   this.label1.Text = "接收資訊：";
   //
   // listBox1
   //
   this.listBox1.Location = new System.Drawing.Point(9, 28);
   this.listBox1.Name = "listBox1";
   this.listBox1.Size = new System.Drawing.Size(318, 121);
   this.listBox1.TabIndex = 1;
   //
   // textBox1
   //
   this.textBox1.Location = new System.Drawing.Point(72, 200);
   this.textBox1.Name = "textBox1";
   this.textBox1.Size = new System.Drawing.Size(183, 20);
   this.textBox1.TabIndex = 3;
   this.textBox1.Text = "";
   //
   // label2
   //
   this.label2.Location = new System.Drawing.Point(26, 203);
   this.label2.Name = "label2";
   this.label2.Size = new System.Drawing.Size(91, 23);
   this.label2.TabIndex = 4;
   this.label2.Text = "資訊：";
   //
   // button1
   //
   this.button1.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
   this.button1.Location = new System.Drawing.Point(272, 200);
   this.button1.Name = "button1";
   this.button1.Size = new System.Drawing.Size(42, 28);
   this.button1.TabIndex = 5;
   this.button1.Text = "發送";
   this.button1.Click += new System.EventHandler(this.button1_Click);
   //
   // button2
   //
   this.button2.FlatStyle = System.Windows.Forms.FlatStyle.Flat;
   this.button2.Location = new System.Drawing.Point(272, 160);
   this.button2.Name = "button2";
   this.button2.Size = new System.Drawing.Size(42, 28);
   this.button2.TabIndex = 6;
   this.button2.Text = "接收";
   this.button2.Click += new System.EventHandler(this.button2_Click);
   //
   // textBox2
   //
   this.textBox2.Location = new System.Drawing.Point(73, 163);
   this.textBox2.Name = "textBox2";
   this.textBox2.Size = new System.Drawing.Size(181, 20);
   this.textBox2.TabIndex = 8;
   this.textBox2.Text = "";
   //
   // label3
   //
   this.label3.Location = new System.Drawing.Point(14, 164);
   this.label3.Name = "label3";
   this.label3.Size = new System.Drawing.Size(52, 23);
   this.label3.TabIndex = 7;
   this.label3.Text = "IP地址：";
   //
   // statusBar1
   //
   this.statusBar1.Location = new System.Drawing.Point(0, 251);
   this.statusBar1.Name = "statusBar1";
   this.statusBar1.Size = new System.Drawing.Size(337, 22);
   this.statusBar1.TabIndex = 9;
   this.statusBar1.Text = "程式不處於資料接收狀態";
   //
   // Form1
   //
   this.AutoScaleBaseSize = new System.Drawing.Size(5, 12);
   this.ClientSize = new System.Drawing.Size(300, 280);
   this.Controls.AddRange(new System.Windows.Forms.Control[] {
                    this.statusBar1,
                    this.textBox2,
                    this.label3,
                    this.button2,
                    this.button1,
                    this.textBox1,
                    this.listBox1,
                    this.label2,
                    this.label1});
   this.MaximizeBox = false;
   this.Name = "Form1";
   this.Text = "UDP聊天";
   this.ResumeLayout(false);

  }
  #endregion

  /// <summary>
  /// 應用程式的主進入點。
  /// </summary>
  [STAThread]
  static void Main ( )
  {
   Application.Run ( new Form1 ( ) ) ;
  }
  private void read ( )
  {
   //偵聽本地的8000連接埠號碼
   udpclient = new UdpClient ( 8000 ) ;
   remote = null ;
   //設定編碼類別型
   Encoding enc = Encoding.Unicode ;
   while ( ReadFlag == true )
   {
    Byte[] data = udpclient.Receive ( ref remote ) ;
    //得到對方發送來的聊天資訊
    String strData = enc.GetString ( data ) ;
    //擷取傳送資訊到本地連接埠號碼的遠端電腦IP地址
    string remoteIP = remote.Address.ToString ( ) ;
    //顯示接收資訊以及傳送資訊的電腦IP地址
    listBox1.Items.Add ( remoteIP + "：" + strData ) ;
   }
  }
  private void button1_Click ( object sender , System.EventArgs e )
  {
   //建立UDP網路服務
   UdpClient SendUdp = new UdpClient ( ) ;
   IPAddress remoteIP ;
   //判斷IP地址的正確性
   try
   {
    remoteIP = IPAddress.Parse ( textBox2.Text );
   }
   catch
   {
    MessageBox.Show ( "請輸入正確的IP地址！" , "錯誤" ) ;
    return ;
   }
   IPEndPoint remoteep = new IPEndPoint ( remoteIP , 8000 ) ;
   Byte [] buffer = null ;
   Encoding enc = Encoding.Unicode ;
   string str = textBox1.Text ;
   buffer = enc.GetBytes ( str.ToCharArray ( ) ) ;
   //傳送資訊到指定電腦的8000連接埠號碼
   SendUdp.Send ( buffer , buffer.Length , remoteep ) ;
   textBox1.Clear ( ) ;
   //關閉UDP網路服務
   SendUdp.Close ( ) ;
  }

  private void button2_Click ( object sender , System.EventArgs e )
  {
   //建立一個線程
   th = new Thread ( new ThreadStart ( read ) ) ;
   //啟動線程
   th.Start ( ) ;
   statusBar1.Text ="程式處於資料接收狀態！" ;
  }
 }
}