调试易

我写了一个udp程序，运行时两端都收不到对方发送的信息。小弟刚刚学socket编程，弄了好久没有搞定。
以下是源代码：
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 UDP程序开发
{
    public partial class Form1 : Form
    {
        private UdpClient client2;
        private IPEndPoint remotehost;
        private int port = 2456;
        private Thread startServer;
        private string sendMessage;
        private string ipadd = "192.168.0.19";
        public Form1()
        {
            InitializeComponent();
        }        private void start_server()
        {
            while (true)
            {
                Byte[] recData = client2.Receive(ref remotehost);
                string Message = System.Text.Encoding.BigEndianUnicode.GetString(recData);
                this.richTextBox1.AppendText(Message);
            }
        }        private void run()
        {
            client2 = new UdpClient(port);
            remotehost = new IPEndPoint(IPAddress.Parse(ipadd),0);
            startServer=new Thread(new ThreadStart(start_server));
            startServer.Start();
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            run();
        }        private void send_Click(object sender, EventArgs e)
        {
            if (this.richTextBox2.Text.Equals(""))
            {
                MessageBox.Show("不能为空,请输入要发送的文字!");
            }
            else
            {
               //run();
               sendMessage = this.richTextBox2.Text;
               Byte[] sendData = System.Text.Encoding.BigEndianUnicode.GetBytes(sendMessage.ToCharArray());
               client2.Connect(remotehost);
               client2.Send(sendData, sendData.Length);
               DateTime time = DateTime.Now;
               this.richTextBox1.AppendText("Client2:"+Convert.ToString(time) + "\n" + sendMessage + "\n");
            }
        }        private void sendData()
        {
            try
            {
                
                Byte[] sendData = System.Text.Encoding.BigEndianUnicode.GetBytes(sendMessage.ToCharArray());
                client2.Connect(remotehost);
                client2.Send(sendData, sendData.Length);
                DateTime time = DateTime.Now;
               //this.richTextBox1.AppendText(Convert.ToString(time) + "\n" + sendMessage + "\n");
            }
            catch (SocketException se)
            {
                MessageBox.Show(se.Message);
            }
        }        private void close_Click(object sender, EventArgs e)
        {
            try
            {
                client2.Close();
            }
            catch
            { 
            }
            this.Dispose();
            this.Close();
        }
    }
}