Tcp客户端的代码

using System;
using System.Windows.Forms;
//添加的命名空间引用
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.IO;
namespace SyncChatClient
{
    public partial class MainForm : Form
    {
        private bool isExit = false;
        private TcpClient client;
        private BinaryReader br;
        private BinaryWriter bw;
        public MainForm()
        {
            InitializeComponent();
            Random r = new Random((int)DateTime.Now.Ticks);//？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？
            textBoxUserName.Text = "user" + r.Next(100, 999);//？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？？
            listBoxOnlineStatus.HorizontalScrollbar = true;//???????????????????????????????????????????????????????????????????????????

        }
        /// <summary>
        /// 【连接服务器】按钮的Click事件
        /// </summary>
        private void buttonConnect_Click(object sender, EventArgs e)
        {
            buttonConnect.Enabled = false;
            try
            {
                //此处为方便演示，实际使用时要将Dns.GetHostName()改为服务器域名
                client = new TcpClient(Dns.GetHostName(), 51888);
                //后面添加的函数，给文本框中添加信息
                AddTalkMessage("连接成功");
            }
            catch
            {
                AddTalkMessage("连接失败");
                buttonConnect.Enabled = true;
                return;
            }
            //获取网络流
            NetworkStream networkStream = client.GetStream();
            //将网络流作为二进制读写对象
            br = new BinaryReader(networkStream);
            bw = new BinaryWriter(networkStream);
            //向服务器端发送信息
            SendMessage("Login," + textBoxUserName.Text);
            Thread threadReceive = new Thread(new ThreadStart(ReceiveData));//???????????????????????????????????????????????????????
            threadReceive.IsBackground = true;//???????????????????????????????????????????????????????????????????????????
            threadReceive.Start();
        }
        /// <summary>处理接收的服务器端数据</summary>
        private void ReceiveData()
        {
            string receiveString = null;
            while (isExit == false)
            {
                try
                {
                    //从网络流中读出字符串
                    //此方法会自动判断字符串长度前缀，并根据长度前缀读出字符串
                    receiveString = br.ReadString();
                }
                catch
                {
                    if (isExit == false)
                    {
                        MessageBox.Show("与服务器失去联系。");
                    }
                    break;
                }
                string[] splitString= receiveString.Split(',');
                string command = splitString[0].ToLower();
                switch (command)
                {
                    case "login":  //格式：login,用户名
                        AddOnline(splitString[1]);//在listBoxOnlineStatus当中添加已经登陆的用户的信息
                        break;
                    case "logout":  //格式：logout,用户名
                        RemoveUserName(splitString[1]);//移除listBoxOnlineStatus当中已经离线的信息
                        break;
                    case "talk":  //格式：talk,用户名,对话信息
                        //AddTalkMessage(splitString[1] + "：\r\n");
                        //AddTalkMessage(receiveString.Substring(
                        //    splitString[0].Length + splitString[1].Length+2));
                        AddTalkMessage(string.Format("[{0}]说：{1}",
                            splitString[1],receiveString.Substring(
                            splitString[0].Length + splitString[1].Length + 2)));
                        break;
                    default:
                        AddTalkMessage("什么意思啊：" + receiveString);
                        break;
                }
            }
            Application.Exit();
        }
        /// <summary>向服务器端发送信息</summary>
        private void SendMessage(string message)
        {
            try
            {
                //将字符串写入网络流，此方法会自动附加字符串长度前缀
                bw.Write(message);
                bw.Flush();
            }
            catch
            {
                AddTalkMessage("发送失败!");
            }
        }
        /// <summary>【发送】按钮的Click事件</summary>
        private void buttonSend_Click(object sender, EventArgs e)
        {
            if (listBoxOnlineStatus.SelectedIndex != -1)
            {
                //SendMessage("Talk," + listBoxOnlineStatus.SelectedItem + "," + textBoxSend.Text+"\r\n");
                SendMessage("Talk," + listBoxOnlineStatus.SelectedItem + "," + textBoxSend.Text);
                textBoxSend.Clear();
            }
            else
            {
                MessageBox.Show("请先在[当前在线]中选择一个对话者");
            }
        }
        /// <summary>关闭窗口时触发的事件</summary>
        private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
        {
            //未与服务器连接前client为null
            if (client != null)
            {
                SendMessage("Logout," + textBoxUserName.Text);
                isExit = true;
                br.Close();
                bw.Close();
                client.Close();
            }
        }
        /// <summary>在发送信息文本框中按下【Enter】键触发的事件</summary>
        private void textBoxSend_KeyPress(object sender, KeyPressEventArgs e)
        {
            if (e.KeyChar == (char)Keys.Return)
            {
                //触发buttonSend的Click事件
                buttonSend.PerformClick();
            }
        }
        private delegate void MessageDelegate(string message);
        /// <summary> 在richTextBoxTalkInfo中追加聊天信息</summary>
        private void AddTalkMessage(string message)
        {
            if (richTextBoxTalkInfo.InvokeRequired)
            {
                MessageDelegate d = new MessageDelegate(AddTalkMessage);
                richTextBoxTalkInfo.Invoke(d, new object[] { message });//?????????????????????????????????????????????
            }
            else
            {
                richTextBoxTalkInfo.AppendText(message + Environment.NewLine);
                richTextBoxTalkInfo.ScrollToCaret();
            }
        }
        private delegate void AddOnlineDelegate(string message);
        /// <summary> 在listBoxOnlineStatus中添加在线的其它客户端信息</summary>
        private void AddOnline(string userName)
        {
            if (listBoxOnlineStatus.InvokeRequired)
            {
                AddOnlineDelegate d = new AddOnlineDelegate(AddOnline);
                listBoxOnlineStatus.Invoke(d, new object[] { userName });
            }
            else
            {
                listBoxOnlineStatus.Items.Add(userName);
                listBoxOnlineStatus.SelectedIndex = listBoxOnlineStatus.Items.Count - 1;
                listBoxOnlineStatus.ClearSelected();
            }
        }
        private delegate void RemoveUserNameDelegate(string userName);
        /// <summary> 在listBoxOnlineStatus中移除不在线的其它客户端信息</summary>
        private void RemoveUserName(string userName)
        {
            if (listBoxOnlineStatus.InvokeRequired)
            {
                RemoveUserNameDelegate d = RemoveUserName;
                listBoxOnlineStatus.Invoke(d, userName);
            }
            else
            {
                listBoxOnlineStatus.Items.Remove(userName);
                listBoxOnlineStatus.SelectedIndex = listBoxOnlineStatus.Items.Count - 1;
                listBoxOnlineStatus.ClearSelected();
            }
        }
    }
}