(转)winform下UPD通信的简单应用

本文转载自：http://blog.csdn.net/wanlong360599336/article/details/7557046

先看效果图：

使用UDP的好处就是不需要三次握手，但是缺点就是存在安全隐患。

QQ就是利用UDP来传输数据的。

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

namespace UDP
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        //启动服务端
        UdpClient udpServer;
        delegate void SetTextCallBack(string text);
        private void button1_Click(object sender, EventArgs e)
        {
            udpServer = new UdpClient();
            label2.Text = "服务器已启动..";
            button1.Enabled = false;
            Thread t = new Thread(new ThreadStart(ReceiveMsg));
            t.IsBackground = true;
            t.Start();  

        }  

        public void ReceiveMsg()
        {
            IPEndPoint ipe = new IPEndPoint(IPAddress.Any, );
            while (true)
            {
                byte[] buffer = udpServer.Receive(ref ipe);
                string msg = Encoding.Unicode.GetString(buffer);
                SetText(msg);
            }  

        }
        public void SetText(string text)
        {
            if (text == "")
            {
                if (richTextBox1.InvokeRequired)
                {
                    SetTextCallBack st = new SetTextCallBack(SetText);
                    this.Invoke(st, new object[] { text });
                }
                else
                {
                    richTextBox1.Text +="小万  " +DateTime.Now.ToString() + "\n" + " " + "\n";
                }
            }
            else
            {  

                    if (richTextBox1.InvokeRequired)
                    {
                        SetTextCallBack st = new SetTextCallBack(SetText);
                        this.Invoke(st, new object[] { text });
                    }
                    else
                    {
                        richTextBox1.Text +="小万  " +DateTime.Now.ToString() + "\n" + text  + "\n";
                    }  

            }
        }
        //客户端
        private void button2_Click(object sender, EventArgs e)
        {
            if (button1.Enabled ==true)
            {
                MessageBox.Show("服务端未开启！");
            }
            else
            {
                UdpClient client = new UdpClient();
                string ip = textBox1.Text;
                string msg = richTextBox2.Text;
                byte[] buffer = Encoding.Unicode.GetBytes(msg);
                IPEndPoint ips = new IPEndPoint(IPAddress.Parse(ip), );
                client.Send(buffer, buffer.Length, ips);
                client.Close();
                MessageBox.Show("发送成功！");
            }  

        }  

    }
}  

自己理解下。