using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using System.Windows.Forms;

using System.Net.Sockets;

using System.Net;

using System.Threading;

namespace _02UDP通訊

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

/// <summary>

/// 用於UDP傳送的網路服務類

/// </summary>

private UdpClient udpcSend;

/// <summary>

/// 用於UDP接收的網路服務類

/// </summary>

private UdpClient udpcRecv;

private void btnSend_Click(object sender, EventArgs e)

{

if (string.IsNullOrWhiteSpace(txtSendMsg.Text))

{

MessageBox.Show("請先輸入待發送內容");

return;

}

// 匿名傳送

//udpcSend = new UdpClient(0); // 自動分配本地IPv4地址

// 實名傳送

IPEndPoint localIpep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 25555); // 本機IP，指定的埠號

udpcSend = new UdpClient(localIpep);

Thread thrSend = new Thread(SendMessage);

thrSend.Start(txtSendMsg.Text);

}

/// <summary>

/// 傳送資訊

/// </summary>

/// <param name="o"></param>

void SendMessage(object o)

{

string message = (string)o;

byte[] sendbytes = Encoding.Unicode.GetBytes(message);

IPEndPoint remoteIpep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8848); // 傳送到的IP地址和埠號

udpcSend.Send(sendbytes, sendbytes.Length, remoteIpep);

udpcSend.Close();

ResetTextBox(txtSendMsg);

}

/// <summary>

/// 開關：在監聽UDP報文階段為true，否則為false

/// </summary>

bool IsUdpcRecvStart = false;

/// <summary>

/// 執行緒：不斷監聽UDP報文

/// </summary>

Thread thrRecv;

/// <summary>

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void btnRecv_Click(object sender, EventArgs e)

{

if (!IsUdpcRecvStart) // 未監聽的情況，開始監聽

{

IPEndPoint localIpep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 8848); // 本機IP和監聽埠號

udpcRecv = new UdpClient(localIpep);

thrRecv = new Thread(ReceiveMessage);

thrRecv.Start();

IsUdpcRecvStart = true;

ShowMessage(txtRecvMsg, "UDP監聽器已成功啟動");

}

else // 正在監聽的情況，終止監聽

{

thrRecv.Abort(); // 必須先關閉這個執行緒，否則會異常

udpcRecv.Close();

IsUdpcRecvStart = false;

ShowMessage(txtRecvMsg, "UDP監聽器已成功關閉");

}

}

/// <summary>

/// 接收資料

/// </summary>

/// <param name="o"></param>

void ReceiveMessage(object o)

{

IPEndPoint remoteIpep = new IPEndPoint(IPAddress.Any, 0);

while (true)

{

try

{

byte[] bytRecv = udpcRecv.Receive(ref remoteIpep);

string message = Encoding.Unicode.GetString( bytRecv, 0, bytRecv.Length);

ShowMessage(txtRecvMsg,string.Format("{0}[{1}]", remoteIpep, message));

}

catch (Exception ex)

{

ShowMessage(txtRecvMsg, ex.Message);

break;

}

}

}

// 向TextBox中新增文字

delegate void ShowMessageDelegate(TextBox txtbox, string message);

void ShowMessage(TextBox txtbox, string message)

{

if (txtbox.InvokeRequired)

{

ShowMessageDelegate showMessageDelegate = ShowMessage;

txtbox.Invoke(showMessageDelegate, new object[] { txtbox, message });

}

else

{

txtbox.Text += message + "\r\n";

}

}

// 清空指定TextBox中的文字

delegate void ResetTextBoxDelegate(TextBox txtbox);

void ResetTextBox(TextBox txtbox)

{

if (txtbox.InvokeRequired)

{

ResetTextBoxDelegate resetTextBoxDelegate = ResetTextBox;

txtbox.Invoke(resetTextBoxDelegate, new object[] { txtbox });

}

else

{

txtbox.Text = "";

}

}

/// <summary>

/// 關閉程式,強制退出

/// </summary>

/// <param name="sender"></param>

/// <param name="e"></param>

private void Form1_FormClosing(object sender, FormClosingEventArgs e)

{

Environment.Exit(0);

}

}

}