我写了这两个服务与客户端的程序，为什么老是出问题，有哪个高手帮忙解决一下
    服务端
using System;
using System.Collections.Generic;
using
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using
using .Sockets ;
using System.Threading;

namespace Receive__
{
    public partial class Form1 : Form
    {

        private IPAddress myIP;
        private IPEndPoint MyServer;
        private Socket sock;
        private bool bb;
        private Socket aaa;
        private Thread thread;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                myIP = IPAddress.Parse(textBox1.Text);
            }
            catch { MessageBox.Show("您输入的ＩＰ地址不正确"); }
            try
            {
                MyServer = new IPEndPoint(myIP, Int32.Parse(textBox2.Text));
                sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                sock.Bind(MyServer);
                sock.Listen(50);
                textBox3.Text = "主机" + textBox1.Text + "端口" + textBox2.Text + "开始监听...";
                thread = new Thread(new ThreadStart(targett));
                thread.Start();

            }
            catch (Exception ee) { textBox3.Text = ee.Message; }
        }

        private void targett()
        {
            aaa = sock.Accept();
            bb = false;
            if (aaa.Connected)
            {
                textBox3.Text = "与客户建立连接。";
                Byte[] bytee =new  Byte[64];
                bytee = System.Text.Encoding.BigEndianUnicode.GetBytes("您好，欢迎使用本服务器!".ToCharArray());
                aaa.Send(bytee, bytee.Length, 0);
                while (!bb)
                {
                    Byte[] bbb = new Byte[64];
                    aaa.Receive(bbb, bbb.Length, 0);
                    string ccc = System.Text.Encoding.BigEndianUnicode.GetString(bbb);
                    richTextBox1.AppendText(ccc + "\r\n");
                    int len = richTextBox1.Lines.Length;
                    if (richTextBox1.Lines[len - 2] == "@@@@@")
                    {
                        textBox3.Text = "与客户断开连接.";
                        aaa.Shutdown();
                        aaa.Close();
                        bb = true;
                    }
                }
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {
                bb = true;
                sock.Close();
                textBox3.Text = "主机" + textBox1.Text + "端口" + textBox2.Text + "停止监听";
            }
            catch { MessageBox.Show("监听尚未开始，关闭无效"); }
        }

    }
}




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

namespace 同步客户端
{
    public partial class Form1 : Form
    {
        private IPAddress myIP = IPAddress.Parse("127.0.0.1");
        private IPEndPoint MyServer;
        private Socket sock;

        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {
                myIP = IPAddress.Parse(textBox1.Text);
            }
            catch { MessageBox.Show("输入的IP不正确"); }
            try
            {
                MyServer = new IPEndPoint(myIP, Int32.Parse(textBox2.Text));
                sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                sock.Connect(MyServer);
                Thread thread=new Thread (new ThreadStart (targett));
                thread.Start ();
                textBox4.Text ="与主机"+textBox1.Text +"端口"+textBox2.Text +"连接成功!";
            }
            catch (Exception ee){MessageBox.Show (ee.Message );}
            
        }
        private void targett()
        {
            Byte[] bbb = new Byte[640];
            sock.Receive(bbb, bbb.Length, 0);
            string aaaaa = System.Text.Encoding.BigEndianUnicode.GetString(bbb);
            textBox4.Text = aaaaa;
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Byte[] bytee = new Byte[640];
            string send = textBox3.Text + "\r\n";
            bytee = System.Text.Encoding.BigEndianUnicode.GetBytes(send.ToCharArray());
            sock.Send(bytee, bytee.Length, 0);
            Thread thread=new Thread (new ThreadStart (targett));
            thread.Start ();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Byte[] bytee = new Byte[64];
            string send = "@@@@@" + "\r\n";
            bytee = System.Text.Encoding.BigEndianUnicode.GetBytes(send.ToCharArray());
            sock.Send(bytee, bytee.Length, 0);
            try
            {
                sock.Close();
                textBox4.Text = "与主机 " + textBox1.Text + "端口" + textBox2.Text + "断开连接!";
            }
            catch { MessageBox.Show("连接尚未建立，断开无效"); }
        }
    }
}