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。