private void btnSocketStart_Click(object sender, EventArgs e)
        {
            int port = getValidPort(tbSocketPort.Text);
            if (port < 0)
            {
                return;
            }
            string ip = this.getIPAddress();
            try
            {
                IPAddress ipAdd = IPAddress.Parse(ip);

                //创建服务器套接字
                listener = new TcpListener(ipAdd, port);

                //开始监听服务器端口
                listener.Start();

                this.rbSocketMsg.AppendText("Socket服务器已经启动，正在监听" + ip + "端口号" + this.tbSocketPort.Text + "\n");

                //启动一个新的线程，执行方法this.StartSocketListen
                //以便在一个独立的进程中执行确认与客户端Socket连接的操作
                ClientSeverForm.SocketServiceFlag = true;
                Thread thread = new Thread(new ThreadStart(this.StartSocketListen));

                thread.Start();
                this.btnSocketStart.Enabled = false;
                this.btnSocketStop.Enabled = true;
            }
            catch (Exception ex)//?????
            {
                this.rbSocketMsg.AppendText(ex.Message.ToString() + "\n");
            }
        }


        //在新的线程中的操作，它主要用于当接收到一个客户端请求时，确认与客户端的链接
        //并且立刻启动一个新的线程来处理和该客户端的信息交互
        private void StartSocketListen()
        {
            while (ClientSeverForm.SocketServiceFlag)
            {
                try
                {
                    //当接收到一个客户端请求时，确认与客户端的链接
                    if (listener.Pending())
                    {
                        Socket socket = listener.AcceptSocket();
                        if (clients.Count >= MAXNUM)
                        {
                            this.rbSocketMsg.AppendText("已经到达了最大连接数：" + MAXNUM + ",拒绝新的连接\n");
                            socket.Close();
                        }
                        else
                        { 
                            //启动一个新的线程
                            //执行方法this.ServiceClient,处理用户相应的请求
                            Client client = new Client(this, socket);
                            Thread clientService = new Thread(new ThreadStart(client.ServiceClient));
                            clientService.Start();
                        }
                    }
                    Thread.Sleep(200);
                }
                catch (Exception ex)
                {
                    this.rbSocketMsg.AppendText(ex.Message.ToString() + "\n");
                }
            }
        }

using System;
using System.Collections.Generic;
using System.Text;

//以下为程序引用到的库文件
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Collections;

namespace chatserver
{
    class Client
    {
        private string name;
        private Socket currentSocket = null;
        private string ipAddress;
        private ClientSeverForm server;

        //保存当前连接的状态
        //closed -->connected ->>closed
        private string state = "CLOSED";

        public Client(ClientSeverForm server, Socket clientSocket)
        {
            this.server = server;
            this.currentSocket = clientSocket;
            ipAddress = getRemoteIpAddress();
        }


        private void SendToCli