C# socket 服务端与客户端通信演示代码
主要实现服务端与客户端消息和文件的相互发送，服务端可以控制客户端：重启、关机、注销，截屏（截客户端的屏）。服务端也可向客户端发送闪屏。

using System;  using System.Collections.Generic;  using System.ComponentModel;  using System.Data;  using System.Drawing;  using System.Net;  using System.Net.Sockets;  using System.Text;  using System.Windows.Forms;  using System.IO;  using System.Threading;  using System.Runtime.InteropServices;      public delegate void DGShowMsg(string strMsg);  namespace Server  {      public partial class Form1 : Form      {          public Form1()          {              InitializeComponent();              TextBox.CheckForIllegalCrossThreadCalls = false;//关闭跨线程修改控件检查              // txtIP.Text = Dns.GetHostEntry(Dns.GetHostName()).AddressList[0].ToString();              txtIP.Text = Dns.GetHostByName(Dns.GetHostName()).AddressList[0].ToString();          }                [DllImport("kernel32")] ///获取系统时间          public static extern void GetSystemTime(ref SYSTEMTIME_INFO stinfo);                          ///定义系统时间结构信息          [StructLayout(LayoutKind.Sequential)]          public struct SYSTEMTIME_INFO          {              public ushort wYear;              public ushort wMonth;              public ushort wDayOfWeek;              public ushort wDay;              public ushort wHour;              public ushort wMinute;              public ushort wSecond;              public ushort wMilliseconds;          }              Socket sokWatch = null;//负责监听 客户端段 连接请求的  套接字(女生宿舍的大妈)          Thread threadWatch = null;//负责 调用套接字， 执行 监听请求的线程                      //开启监听 按钮          private void btnStartListen_Click(object sender, EventArgs e)          {              //实例化 套接字 （ip4寻址协议，流式传输，TCP协议）              sokWatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);                                  //创建 ip对象              IPAddress address = IPAddress.Parse(txtIP.Text.Trim());             // IPAddress[] addressList = Dns.GetHostEntry(Dns.GetHostName()).AddressList;              //string ip= this.geta              //创建网络节点对象 包含 ip和port             // IPEndPoint endpoint = new IPEndPoint(address, int.Parse(txtPort.Text.Trim())); comboBox1.Text.Trim();              IPEndPoint endpoint = new IPEndPoint(address, int.Parse(comboBox1.Text.Trim()));              //将 监听套接字  绑定到 对应的IP和端口              sokWatch.Bind(endpoint);              //设置 监听队列 长度为10(同时能够处理 10个连接请求)              sokWatch.Listen(20);              threadWatch = new Thread(StartWatch);              threadWatch.IsBackground = true;              threadWatch.Start();              //txtShow.AppendText("启动服务器成功......rn");              label4.Text = "启动服务器成功......";                          }          //Dictionary<string, Socket> dictSocket = new Dictionary<string, Socket>();          Dictionary<string, ConnectionClient> dictConn = new Dictionary<string, ConnectionClient>();              bool isWatch = true;              #region 1.被线程调用 监听连接端口          /// <summary>          /// 被线程调用 监听连接端口          /// </summary>          void StartWatch()          {              string recode;              while (isWatch)              {                  //threadWatch.SetApartmentState(ApartmentState.STA);                  //监听 客户端 连接请求，但是，Accept会阻断当前线程                  Socket sokMsg = sokWatch.Accept();//监听到请求，立即创建负责与该客户端套接字通信的套接字                  ConnectionClient connection = new ConnectionClient(sokMsg, ShowMsg, RemoveClientConnection);                  //将负责与当前连接请求客户端 通信的套接字所在的连接通信类 对象 装入集合                  dictConn.Add(sokMsg.RemoteEndPoint.ToString(), connection);                  //将 通信套接字 加入 集合，并以通信套接字的远程IpPort作为键                  //dictSocket.Add(sokMsg.RemoteEndPoint.ToString(), sokMsg);                  //将 通信套接字的 客户端IP端口保存在下拉框里                  cboClient.Items.Add(sokMsg.RemoteEndPoint.ToString());                  MessageBox.Show("有一个客户端新添加！");                  recode = sokMsg.RemoteEndPoint.ToString();                  //调用GetSystemTime函数获取系统时间信息                  SYSTEMTIME_INFO StInfo; StInfo = new SYSTEMTIME_INFO();                  GetSystemTime(ref StInfo);                  recode +="子计算机在"+StInfo.wYear.ToString() + "年" + StInfo.wMonth.ToString() + "月" + StInfo.wDay.ToString() + "日";                  recode += (StInfo.wHour + 8).ToString() + "点" + StInfo.wMinute.ToString() + "分" + StInfo.wSecond.ToString() + "秒"+"连接服务";                                      //记录每台子计算机连接服务主机的日志                  StreamWriter m_sw = new StreamWriter(System.Windows.Forms.Application.StartupPath + @"\file.DAT", true);                  m_sw.WriteLine(recode);                  m_sw.WriteLine("------------------------------------------------------------------");                  m_sw.Close();                  //MessageBox.Show(recode);                  dictConn[sokMsg.RemoteEndPoint.ToString()].SendTrue();                  //启动一个新线程，负责监听该客户端发来的数据                  //Thread threadConnection = new Thread(ReciveMsg);                  //threadConnection.IsBackground = true;                  //threadConnection.Start(sokMsg);                                  }          }          #endregion              //bool isRec = true;          //与客户端通信的套接字 是否 监听消息              #region 发送消息 到指定的客户端 -btnSend_Click          //发送消息 到指定的客户端              private void btnSend_Click(object sender, EventArgs e)          {              //byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(txtInput.Text.Trim());              //从下拉框中 获得 要哪个客户端发送数据              string time;              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  //从字典集合中根据键获得 负责与该客户端通信的套接字，并调用send方法发送数据过去                  dictConn[connectionSokKey].Send(txtInput.Text.Trim());                  SYSTEMTIME_INFO StInfo; StInfo = new SYSTEMTIME_INFO();                  GetSystemTime(ref StInfo);                  time = StInfo.wYear.ToString() + "/" + StInfo.wMonth.ToString() + "/" + StInfo.wDay.ToString() +"  ";                  time += (StInfo.wHour + 8).ToString() + ":" + StInfo.wMinute.ToString();                  richTextBox1.AppendText(time + "rn");                  richTextBox1.AppendText("对" + cboClient.Text +"说："+ txtInput.Text.Trim() + "rn");                  txtInput.Text = "";                  //sokMsg.Send(arrMsg);              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }          #endregion              //发送闪屏          private void btnShack_Click(object sender, EventArgs e)          {              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  dictConn[connectionSokKey].SendShake();              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }          //群闪          private void btnShackAll_Click(object sender, EventArgs e)          {              foreach (ConnectionClient conn in dictConn.Values)              {                  conn.SendShake();              }          }                     #region 2 移除与指定客户端的连接 +void RemoveClientConnection(string key)          /// <summary>          /// 移除与指定客户端的连接          /// </summary>          /// <param name="key">指定客户端的IP和端口</param>          public void RemoveClientConnection(string key)          {              if (dictConn.ContainsKey(key))              {                  dictConn.Remove(key);                  MessageBox.Show(key +"断开连接");                  cboClient.Items.Remove(key);              }          }          #endregion              //选择要发送的文件          private void btnChooseFile_Click(object sender, EventArgs e)          {              OpenFileDialog ofd = new OpenFileDialog();              if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)              {                  txtFilePath.Text = ofd.FileName;              }          }              //发送文件          private void btnSendFile_Click(object sender, EventArgs e)          {              //拿到下拉框中选中的客户端IPPORT              string key = cboClient.Text;              if (!string.IsNullOrEmpty(key))              {                  dictConn[key].SendFile(txtFilePath.Text.Trim());                 // txtFilePath.Text = "";              }              else              {                  MessageBox.Show("请选择要发送的子计算机~");              }          }              #region 向文本框显示消息 -void ShowMsg(string msgStr)          /// <summary>          /// 向文本框显示消息          /// </summary>          /// <param name="msgStr">消息</param>          public void ShowMsg(string msgStr)          {              //MessageBox.Show("1040414");              txtShow1.AppendText(msgStr + "rn");          }          #endregion  //群消息          private void btnSendMsgAll_Click(object sender, EventArgs e)          {              string time;              foreach (ConnectionClient conn in dictConn.Values)              {                  conn.Send(txtInput.Text.Trim());                                  }              SYSTEMTIME_INFO StInfo; StInfo = new SYSTEMTIME_INFO();              GetSystemTime(ref StInfo);              time = StInfo.wYear.ToString() + "/" + StInfo.wMonth.ToString() + "/" + StInfo.wDay.ToString()  + "  ";              time += (StInfo.wHour + 8).ToString() + ":" + StInfo.wMinute.ToString();              richTextBox1.AppendText(time + "rn");              richTextBox1.AppendText("群发消息："+ txtInput.Text.Trim() + "rn");              txtInput.Text = "";          }  //群发文件          private void button1_Click(object sender, EventArgs e)          {                  foreach (ConnectionClient conn in dictConn.Values)              {                 // dictConn.SendFile(txtFilePath.Text.Trim());                  conn.SendFile(txtFilePath.Text.Trim());                                      }          }              private void button2_Click(object sender, EventArgs e)          {              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  dictConn[connectionSokKey].guanji();              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }              private void button3_Click(object sender, EventArgs e)          {              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  dictConn[connectionSokKey].chongqi();              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }              private void button4_Click(object sender, EventArgs e)          {              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  dictConn[connectionSokKey].zhuxiao();              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }              private void button5_Click(object sender, EventArgs e)          {              string connectionSokKey = cboClient.Text;              if (!string.IsNullOrEmpty(connectionSokKey))              {                  dictConn[connectionSokKey].jieping();              }              else              {                  MessageBox.Show("请选择要发送的子计算机～～");              }          }                         }      ///////////////////////////////////////////////////////////////////////////////////////     ////////////////////////////////////////////////////////////////////////////////////////     ////在这里,我新建了一个与客户端的通信和线程的类(ConnectionClient)//////////////////////      /// <summary>      /// 与客户端的 连接通信类(包含了一个 与客户端 通信的 套接字，和线程)      /// </summary>     public class ConnectionClient      {          Socket sokMsg;          DGShowMsg dgShowMsg;//负责 向主窗体文本框显示消息的方法委托          DGShowMsg dgRemoveConnection;// 负责 从主窗体 中移除 当前连接          Thread threadMsg;              #region 构造函数          /// <summary>          ///          /// </summary>          /// <param name="sokMsg">通信套接字</param>          /// <param name="dgShowMsg">向主窗体文本框显示消息的方法委托</param>          public ConnectionClient(Socket sokMsg, DGShowMsg dgShowMsg, DGShowMsg dgRemoveConnection)          {              this.sokMsg = sokMsg;              this.dgShowMsg = dgShowMsg;              this.dgRemoveConnection = dgRemoveConnection;                  this.threadMsg = new Thread(RecMsg);              this.threadMsg.IsBackground = true;              this.threadMsg.Start();          }          #endregion              bool isRec = true;          #region 02负责监听客户端发送来的消息          void RecMsg()          {              while (isRec)              {                  try                  {                      byte[] arrMsg = new byte[1024 * 1024 * 1];                      //接收 对应 客户端发来的消息                      int length = sokMsg.Receive(arrMsg);                      // string abc = Encoding.Default.GetString(arrMsg);                      // MessageBox.Show(abc);                      //将接收到的消息数组里真实消息转成字符串                                                             if (arrMsg[0] == 1)                      {                           //string abc = Encoding.Default.GetString(arrMsg);                           //MessageBox.Show(abc);                           //发送来的是文件                           //MessageBox.Show("00000s");                           //SaveFileDialog sfd = new SaveFileDialog();                           SaveFileDialog sfd = new SaveFileDialog();                           sfd.Filter = "文本文件(.txt)|*.txt|所有文件(*.*)|*.*";                           // MessageBox.Show(sfd.Filter);                                                       //sfd.ShowDialog();                           //弹出文件保存选择框                           if (sfd.ShowDialog() == System.Windows.Forms.DialogResult.OK)                           {                               //MessageBox.Show("111110");                               //创建文件流                               using (FileStream fs = new FileStream(sfd.FileName, FileMode.OpenOrCreate))                               {                                   fs.Write(arrMsg, 1, length - 1);                                   MessageBox.Show("文件保存成功！");                               }                           }                       }                      /*else if(arrMsg[0] == 2)                      {                                                      //  MemoryStream ms = new MemoryStream(arrMsg, 0, length-1);                          MemoryStream ms = new MemoryStream(arrMsg);                          Image returnImage = Image.FromStream(ms);//??????????                          PictureBox district = (PictureBox)Application.OpenForms["Form1"].Controls["pictureBox1"].Controls["pictureBox1"];                          district.Image  =  returnImage;                         // this.saveFileDialog1.FileName = "";//清空名称栏                                                   /*                            SaveFileDialog sfd = new SaveFileDialog();                          sfd.Filter = "图像文件(.jpg)|*.jpg|所有文件(*.*)|*.*";                          MessageBox.Show(sfd.Filter);                          if (DialogResult.OK == sfd.ShowDialog())                          {                              string strFileName = sfd.FileName;                              //Image img = (Image)this.pictureBox1.Image;                              returnImage.Save(strFileName);                          }                                                 }*/                       else//发送来的是消息                       {                          //MessageBox.Show("2222");                          string strMsg = sokMsg.RemoteEndPoint.ToString()+"说："+"rn"+System.Text.Encoding.UTF8.GetString(arrMsg, 0, length); //// 我在这里  Request.ServerVariables.Get("Remote_Addr").ToString()+                          //通过委托 显示消息到 窗体的文本框                          dgShowMsg(strMsg);                        }                                                                                                    //MessageBox.Show("11111");                }                catch (Exception ex)                 {                    isRec = false;                   //从主窗体中 移除 下拉框中对应的客户端选择项，同时 移除 集合中对应的 ConnectionClient对象                      dgRemoveConnection(sokMsg.RemoteEndPoint.ToString());                  }              }          }          #endregion              #region 03向客户端发送消息          /// <summary>          /// 向客户端发送消息          /// </summary>          /// <param name="strMsg"></param>          public void Send(string strMsg)          {              byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(strMsg);              byte[] arrMsgFinal = new byte[arrMsg.Length + 1];                  arrMsgFinal[0] = 0;//设置 数据标识位等于0，代表 发送的是 文字              arrMsg.CopyTo(arrMsgFinal, 1);                  sokMsg.Send(arrMsgFinal);          }          #endregion              #region 04向客户端发送文件数据 +void SendFile(string strPath)          /// <summary>          /// 04向客户端发送文件数据          /// </summary>          /// <param name="strPath">文件路径</param>          public void SendFile(string strPath)          {              //通过文件流 读取文件内容              //MessageBox.Show("12540");              using (FileStream fs = new FileStream(strPath, FileMode.OpenOrCreate))              {                  byte[] arrFile = new byte[1024 * 1024 * 2];                  //读取文件内容到字节数组，并 获得 实际文件大小                  int length = fs.Read(arrFile, 0, arrFile.Length);                  //定义一个 新数组，长度为文件实际长度 +1                  byte[] arrFileFina = new byte[length + 1];                  arrFileFina[0] = 1;//设置 数据标识位等于1，代表 发送的是文件                  //将 文件数据数组 复制到 新数组中，下标从1开始                  //arrFile.CopyTo(arrFileFina, 1);                  Buffer.BlockCopy(arrFile, 0, arrFileFina, 1, length);                 // MessageBox.Show("120");                  //发送文件数据                  sokMsg.Send(arrFileFina);//, 0, length + 1, SocketFlags.None);              }          }          #endregion              #region 05向客户端发送闪屏          /// <summary>          /// 向客户端发送闪屏          /// </summary>          /// <param name="strMsg"></param>          public void SendShake()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 2;              sokMsg.Send(arrMsgFinal);          }          #endregion              #region 06关闭与客户端连接          /// <summary>          /// 关闭与客户端连接          /// </summary>          public void CloseConnection()          {              isRec = false;          }          #endregion              #region 07向客户端发送连接成功提示          /// <summary>          /// 向客户端发送连接成功提示          /// </summary>          /// <param name="strMsg"></param>          public void SendTrue()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 3;              sokMsg.Send(arrMsgFinal);          }          #endregion              #region 08向客户端发送关机命令          /// <summary>          /// 向客户端发送关机命令          /// </summary>          /// <param name="strMsg"></param>          public void guanji()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 4;              sokMsg.Send(arrMsgFinal);          }          #endregion              #region 09向客户端发送重启命令          /// <summary>          /// 向客户端发送关机命令          /// </summary>          /// <param name="strMsg"></param>          public void chongqi()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 5;              sokMsg.Send(arrMsgFinal);          }          #endregion              #region 10向客户端发送待机命令          /// <summary>          /// 向客户端发送关机命令          /// </summary>          /// <param name="strMsg"></param>          public void zhuxiao()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 6;              sokMsg.Send(arrMsgFinal);          }         #endregion              #region 11向客户端发送截屏命令          /// <summary>          /// 向客户端发送截屏命令          /// </summary>          /// <param name="strMsg"></param>          public void jieping()          {              byte[] arrMsgFinal = new byte[1];              arrMsgFinal[0] = 7;              sokMsg.Send(arrMsgFinal);          }          #endregion      }      }

using System;  using System.Collections.Generic;  using System.ComponentModel;  using System.Data;  using System.Drawing;  using System.Net.Sockets;  using System.Net;  using System.Threading;  using System.Windows.Forms;  using System.IO;  using System.Text;  using System.Runtime.InteropServices;          public delegate void DGShowMsg(string strMsg);  namespace Client  {      public partial class Form1 : Form      {          public Form1()          {              InitializeComponent();              TextBox.CheckForIllegalCrossThreadCalls = false;                          }          #region[成员函数]          ///<summary>          ///图像函数          ///</summary>          private Image _img;          #endregion          [StructLayout(LayoutKind.Sequential, Pack = 1)]              internal struct TokPriv1Luid          {                  public int Count;                  public long Luid;                  public int Attr;              }              [DllImport("kernel32.dll", ExactSpelling = true)]              internal static extern IntPtr GetCurrentProcess();              [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]              internal static extern bool OpenProcessToken(IntPtr h, int acc, ref IntPtr phtok);              [DllImport("advapi32.dll", SetLastError = true)]              internal static extern bool LookupPrivilegeValue(string host, string name, ref long pluid);              [DllImport("advapi32.dll", ExactSpelling = true, SetLastError = true)]              internal static extern bool AdjustTokenPrivileges(IntPtr htok, bool disall,              ref TokPriv1Luid newst, int len, IntPtr prev, IntPtr relen);              [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]              internal static extern bool ExitWindowsEx(int flg, int rea);              internal const int SE_PRIVILEGE_ENABLED = 0x00000002;              internal const int TOKEN_QUERY = 0x00000008;              internal const int TOKEN_ADJUST_PRIVILEGES = 0x00000020;              internal const string SE_SHUTDOWN_NAME = "SeShutdownPrivilege";              internal const int EWX_LOGOFF = 0x00000000;  //注销              internal const int EWX_SHUTDOWN = 0x00000001;   //关机              internal const int EWX_REBOOT = 0x00000002;     //重启              internal const int EWX_FORCE = 0x00000004;              internal const int EWX_POWEROFF = 0x00000008;    //断开电源              internal const int EWX_FORCEIFHUNG = 0x00000010;  //强制终止未响应的程序             // internal const int WM_POWERBROADCAST                            private static void DoExitWin(int flg)          {                  bool ok;                  TokPriv1Luid tp;                  IntPtr hproc = GetCurrentProcess();                  IntPtr htok = IntPtr.Zero;                  ok = OpenProcessToken(hproc, TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref htok);                  tp.Count = 1;                  tp.Luid = 0;                  tp.Attr = SE_PRIVILEGE_ENABLED;                  ok = LookupPrivilegeValue(null, SE_SHUTDOWN_NAME, ref tp.Luid);                  ok = AdjustTokenPrivileges(htok, false, ref tp, 0, IntPtr.Zero, IntPtr.Zero);                  ok = ExitWindowsEx(flg, 0);              }                  Socket sokClient = null;//负责与服务端通信的套接字          Thread threadClient = null;//负责 监听 服务端发送来的消息的线程          bool isRec = true; //是否循环接收服务端数据         // Dictionary<string, ConnectionClient> dictConn = new Dictionary<string, ConnectionClient>();          private void btnConnect_Click(object sender, EventArgs e)          {              //实例化 套接字              sokClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);              //创建 ip对象              IPAddress address = IPAddress.Parse(txtIP.Text.Trim());              //MessageBox.Show("address");              //创建网络节点对象 包含 ip和port              IPEndPoint endpoint = new IPEndPoint(address, int.Parse(comboBox1.Text.Trim()));              //连接 服务端监听套接字              sokClient.Connect(endpoint);                  //创建负责接收 服务端发送来数据的 线程              threadClient = new Thread(ReceiveMsg);              threadClient.IsBackground = true;              //如果在win7下要通过 某个线程 来调用 文件选择框的代码，就需要设置如下              threadClient.SetApartmentState(ApartmentState.STA);              threadClient.Start();          }                         /// <summary>          /// 接收服务端发送来的消息数据          /// </summary>          void ReceiveMsg()          {              while (isRec)              {                  byte[] msgArr = new byte[1024 * 1024 * 1];//接收到的消息的缓冲区                  int length = 0;                  //接收服务端发送来的消息数据                  length = sokClient.Receive(msgArr);//Receive会阻断线程                  if (msgArr[0] == 0)//发送来的是文字                  {                      string strMsg = System.Text.Encoding.UTF8.GetString(msgArr, 1, length - 1);                      txtShow.AppendText(strMsg + "rn");                  }                  else if (msgArr[0] == 1)                  {                      //发送来的是文件                      //string abc = Encoding.Default.GetString(msgArr);                      //MessageBox.Show(abc);                      SaveFileDialog sfd = new SaveFileDialog();                      sfd.Filter = "文本文件(.txt)|*.txt|所有文件(*.*)|*.*";                      //弹出文件保存选择框                      if (sfd.ShowDialog() == System.Windows.Forms.DialogResult.OK)                      {                          //创建文件流                          using (FileStream fs = new FileStream(sfd.FileName, FileMode.OpenOrCreate))                          {                              fs.Write(msgArr, 1, length - 1);                              MessageBox.Show("文件保存成功！");                          }                      }                  }                  else if (msgArr[0] == 2)                  {                      ShakeWindow();                  }                  else if (msgArr[0] == 3)                  {                      MessageBox.Show("连接成功");                  }                  else if (msgArr[0] == 4)                  {                      DoExitWin(EWX_SHUTDOWN);                   }                  else if (msgArr[0] == 5)                  {                      DoExitWin(EWX_REBOOT);                  }                  else if (msgArr[0] == 6)                  {                      DoExitWin(EWX_LOGOFF);                  }                  else if (msgArr[0] == 7)                  {                                             PrintScreen();                  }                  }          }              #region[方法]          ///<summary>          ///截屏          ///</summary>          private void PrintScreen()          {                             string Opath = @"C:/Picture";              if (Opath.Substring(Opath.Length - 1, 1) != @"/")                 Opath = Opath + @"/";              string photoname = DateTime.Now.Ticks.ToString();              string path1 = Opath + DateTime.Now.ToShortDateString();              if (!Directory.Exists(path1))                  Directory.CreateDirectory(path1);              try              {                                 Screen scr = Screen.PrimaryScreen;                  Rectangle rc = scr.Bounds;                  int iWidth = rc.Width;                  int iHeight = rc.Height;                  Bitmap myImage = new Bitmap(iWidth, iHeight);                  Graphics gl = Graphics.FromImage(myImage);                  gl.CopyFromScreen(new Point(0, 0), new Point(0, 0), new Size(iWidth, iHeight));                  _img = myImage;                  //pictureBox1.Image = _img;                  // IntPtr dc1 = gl.GetHdc();                  //gl.ReleaseHdc(dc1);                  MessageBox.Show(path1);                  MessageBox.Show(photoname);                  _img.Save(path1 + "//" + photoname + ".jpg", System.Drawing.Imaging.ImageFormat.Jpeg);                  // _img.Save("D:\1.jpeg");                  SendFile(path1+"//"+photoname+".jpg");              }              catch (Exception ex)              {                  MessageBox.Show("截屏失败！n" + ex.Message.ToString() + "n" + ex.StackTrace.ToString());              }                             // MessageBox.Show("12322222");              /////////////////////////////////////////////////////////              ///////////////////发送图片流///////////////////////////             /*              MemoryStream ms = new MemoryStream();              byte[] imagedata = null;              _img.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);              imagedata = ms.GetBuffer();                  byte[] arrFile = new byte[1024 * 1024 * 2];              //读取文件内容到字节数组，并 获得 实际文件大小              int length = ms.Read(arrFile, 0, arrFile.Length);              // int length = ms.Read(arrFile, 0, arrFile.Length);              //定义一个 新数组，长度为文件实际长度 +1              byte[] arrFileFina = new byte[length + 1];              arrFileFina[0] = 2;//设置 数据标识位等于1，代表 发送的是文件              //将 图片流数据数组 复制到 新数组中，下标从1开始              //arrFile.CopyTo(arrFileFina, 1);              Buffer.BlockCopy(arrFile, 0, arrFileFina, 1, length);              //发送文件数据               sokClient.Send(arrFileFina);//, 0, length + 1, SocketFlags.None);              //MessageBox.Show("我在这里！！！");              // byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(_img);              MessageBox.Show("2222");              */          }          #endregion  /*          private void button1_Click(object sender, EventArgs e)          {              // this.WindowState = FormWindowState.Minimized;              PrintScreen();              if (_img != null)              {                  this.pictureBox1.Image = _img;              }              this.WindowState = FormWindowState.Normal;          }  */          /// <summary>          /// 闪屏          /// </summary>          private void ShakeWindow()          {              Random ran = new Random();              //保存 窗体原坐标              System.Drawing.Point point = this.Location;              for (int i = 0; i < 30; i++)              {                  //随机 坐标                  this.Location = new System.Drawing.Point(point.X + ran.Next(8), point.Y + ran.Next(8));                  System.Threading.Thread.Sleep(15);//休息15毫秒                  this.Location = point;//还原 原坐标(窗体回到原坐标)                  System.Threading.Thread.Sleep(15);//休息15毫秒              }          }          //发送消息          private void btnSend_Click(object sender, EventArgs e)          {              byte[] arrMsg = System.Text.Encoding.UTF8.GetBytes(txtInput.Text.Trim());              sokClient.Send(arrMsg);              richTextBox1.AppendText(txtInput.Text.Trim()+"rn");              txtInput.Text = "";          }              private void btnChooseFile_Click(object sender, EventArgs e)          {              OpenFileDialog ofd = new OpenFileDialog();              if (ofd.ShowDialog() == System.Windows.Forms.DialogResult.OK)              {                  txtFilePath.Text = ofd.FileName;              }          }          //发送文件          private void btnSendFile_Click(object sender, EventArgs e)          {              string key = txtIP.Text + ":" + comboBox1.Text.Trim();              //MessageBox.Show(key);              if (!string.IsNullOrEmpty(key))              {                  SendFile(txtFilePath.Text.Trim());                 // MessageBox.Show("1230");                  // txtFilePath.Text = "";              }          }          private void SendFile(string strPath)          {              //通过文件流 读取文件内容                             using (FileStream fs = new FileStream(strPath, FileMode.OpenOrCreate))              {                  byte[] arrFile = new byte[1024 * 1024 * 2];                  //读取文件内容到字节数组，并 获得 实际文件大小                  int length = fs.Read(arrFile, 0, arrFile.Length);                  //定义一个 新数组，长度为文件实际长度 +1                  byte[] arrFileFina = new byte[length + 1];                  arrFileFina[0] = 1;//设置 数据标识位等于1，代表 发送的是文件                  //将 文件数据数组 复制到 新数组中，下标从1开始                  //arrFile.CopyTo(arrFileFina, 1);                  Buffer.BlockCopy(arrFile, 0, arrFileFina, 1, length);                  //发送文件数据                   sokClient.Send(arrFileFina);//, 0, length + 1, SocketFlags.None);                  //MessageBox.Show("我在这里！！！");              }          }      }           }