局域网UDP聊天程序桌面版

说明

最简单的聊天程序：采用UDP实现。学习用，无实用价值。

注释很详细就不再说明了，监听的时候使用死循环，注意用到了跨线程操作控件、强制结束线程。

改进

实用委托实现线程安全的方式操作控件，等待线程结束。

代码

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

namespace WindowsApplication2
{
publicpartialclass Form1 : Form
{
public Form1()
{
InitializeComponent();
}

privatevoid textBox1_TextChanged(object sender, EventArgs e)
{

}

privatevoid Form1_Load(object sender, EventArgs e)
{
richTextBox2.Focus();
}

privatevoid richTextBox2_TextChanged(object sender, EventArgs e)
{

}
Thread th;
privatevoid button1_Click(object sender, EventArgs e)
{

th =new Thread(new ThreadStart(this.ServerStart));
th.Start();
messageinfo +="聊天程序启动！\r\n";
richTextBox1.Text = messageinfo;
}
//保存聊天记录（因为没有找到跨线程取控件值的方法。）
staticstring messageinfo ="";

///<summary>
/// 发送聊天记录。
///</summary>
///<param name="message">聊天记录</param>
///<param name="toanyone">发给对方的IP</param>
///<param name="port">端口号。</param>
void SendMessage(string message, string toanyone,int port)
{
//UDP连接对象
UdpClient udpclient =new UdpClient(toanyone, port);
//发送的消息
byte[] bytes = Encoding.UTF8.GetBytes(message);
//发送消息
udpclient.Send(bytes, bytes.Length);

messageinfo +="您说："+ message +""+ DateTime.Now.ToString() +"\r\n";
this.richTextBox1.Text +="您说："+ message +""+ DateTime.Now.ToString() +"\r\n";
//Console.WriteLine("您说：" + message + " " + DateTime.Now.ToString());
//Console.WriteLine("-------------------------------");
}
///<summary>
/// 开始监听
///</summary>
void ServerStart()
{
Console.WriteLine("-----------开始监听------------");
//定义UDP监听
UdpClient udplistener =new UdpClient(8090);

//这里定义监听到的客户端的信息，IP
IPEndPoint guest =new IPEndPoint(IPAddress.Any, 8090);
//注意这里由于是死循环，必须用子线程启动
while (true)
{
string Recevied ="";

//接收监听到的信息
byte[] bytes = udplistener.Receive(ref guest);
Recevied ="信息来自："+ guest.Address.ToString() +"说："+ Encoding.UTF8.GetString(bytes)+""+DateTime.Now.ToString()+"\r\n";
//this.richTextBox1.Text += Recevied;
//Recevied = GetText() +"\r\n"+ Recevied;

messageinfo += Recevied;
//跨线程操作控件
SetText( messageinfo);
}
}
privatevoid button2_Click(object sender, EventArgs e)
{
if (richTextBox2.Text.Trim() =="")
{
MessageBox.Show("不容许发送空记录！");
return;
}
string toanyone =this.textBox1.Text;
int port =int.Parse(this.textBox2.Text);
SendMessage(this.richTextBox2.Text,toanyone,port);
richTextBox2.Text ="";
}
///<summary>
/// 跨线程操作控件
///</summary>
///<param name="text"></param>
delegatevoid SetTextCallback(string text);
privatevoid SetText(string text)
{
// InvokeRequired required compares the thread ID of the
// calling thread to the thread ID of the creating thread.
// If these threads are different, it returns true.
if (this.richTextBox1.InvokeRequired)
{
SetTextCallback d =new SetTextCallback(SetText);
this.Invoke(d, newobject[] { text });
}
else
{
this.richTextBox1.Text = text;
}
}

privatevoid Form1_FormClosing(object sender, FormClosingEventArgs e)
{
//th.Abort();
//强制退出。有子线程可能没结束。（监听的线程）
System.Environment.Exit(0);
Application.Exit();
}

privatevoid button3_Click(object sender, EventArgs e)
{
messageinfo ="";
richTextBox1.Text ="";
}

privatevoid richTextBox1_TextChanged(object sender, EventArgs e)
{
//使得聊天窗口总是显示最新的消息
richTextBox1.SelectionStart = richTextBox1.Text.Length;
richTextBox1.Focus();
//使得输入聊天信息 的文本框获得焦点，便于用户输入
richTextBox2.Focus();
}
}
}

由于又要忙了，留下来做记录。