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(3000);  
            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, 3000);  
            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), 3000);  
                client.Send(buffer, buffer.Length, ips);  
                client.Close();  
                MessageBox.Show("发送成功！");  
            }  
  
        }  
       
    }  
}