c# messagebox的用法

using System;

using System.Collections.Generic;

using System.ComponentModel;

using ;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using .Forms;

using .Sockets;

using ;

using System.Threading;

namespace _02UDP通信

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

/// <summary>

/// 用于UDP发送的网络服务类

/// </summary>

private UdpClient udpcSend;

/// <summary>

/// 用于UDP接收的网络服务类

/// </summary>

private UdpClient udpcRecv;

private void btnSend_Click(object sender, EventArgs e)

{

if (string.IsNullOrWhiteSpace(txtSendMsg.Text))

{

("请先输入待发送内容");

return;

}

// 匿名发送

//udpcSend = new UdpClient(0); // 自动分配本地IPv4地址

// 实名发送

IPEndPoint localIpep = new IPEndPoint(IPAddress.Parse(""), 25555); // 本机IP，指定的端口号

udpcSend = new UdpClient(localIpep);

Thread thrSend = new Thread(SendMessage);

thrSend.Start(txtSendMsg.Text);

}

/// <summary>

/// 发送信息

/// </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(""), 8848); // 发送到的IP地址和端口号

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

udpcSend.Close();

ResetTextBox(txtSendMsg);

}

/// <summary>

/// 开关：在监听UDP报文阶段为true，否则为false

/// </summary>

bool IsUdpcRecvStart = false;

/// <summary>

/// 线程：不断监听UDP报文

/// </summary>

Thread thrRecv;

/// <summary>

/// 按钮：接收数据开关

/// </summary>

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

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

private void btnRecv_Click(object sender, EventArgs e)

{

if (!IsUdpcRecvStart) // 未监听的情况，开始监听

{

IPEndPoint localIpep = new IPEndPoint(IPAddress.Parse(""), 8848); // 本机IP和监听端口号

udpcRecv = new UdpClient(localIpep);

thrRecv = new Thread(ReceiveMessage);

thrRecv.Start();

IsUdpcRecvStart = true;

ShowMessage(txtRecvMsg, "UDP监听器已成功启动");

}

else // 正在监听的情况，终止监听

{

thrRecv.Abort(); // 必须先关闭这个线程，否则会异常

udpcRecv.Close();

IsUdpcRecvStart = false;

ShowMessage(txtRecvMsg, "UDP监听器已成功关闭");

}

}

/// <summary>

/// 接收数据

/// </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中添加文本

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中的文本

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>

/// 关闭程序,强制退出

/// </summary>

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

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

private void Form1_FormClosing(object sender, FormClosingEventArgs e)

{

(0);

}

}

}