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！");

            }  

        }  

    }

}