c# socket 断线重连

private void Timer_Tick(object sender, EventArgs e)
 
{
 
Socket_wrapper.checkSocketState();
 
}
补充：之前为啥没有写 接收服务器端的方法，现在补上
  
socket封装类，socket换成TcpClient  
  
 
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Net.Sockets; using System.Net; using System.Threading; using System.Runtime.InteropServices;   namespace TcpDisconnectDemo {     public class Socket_wrapper     {         //委托         public  delegate void delSocketDataArrival(byte[] data);         public static  delSocketDataArrival socketDataArrival = socketDataArrivalHandler;           public delegate void delSocketDisconnected();         public static  delSocketDisconnected socketDisconnected = socketDisconnectedHandler;           public static TcpClient theSocket = null;         private static string remoteHost = "192.168.1.71";         private static int remotePort = 6666;           private static String SockErrorStr = null;         private static ManualResetEvent TimeoutObject = new ManualResetEvent(false);         private static Boolean IsconnectSuccess = false; //异步连接情况，由异步连接回调函数置位         private static object lockObj_IsConnectSuccess = new object();           ///           /// 构造函数         ///          ///          ///          public Socket_wrapper(string strIp, int iPort)         {             remoteHost = strIp;             remotePort = iPort;         }         private static byte[] KeepAliveTime         {             get             {                 uint dummy = 0;                 byte[] inOptionValues = new byte[Marshal.SizeOf(dummy) * 3];                 BitConverter.GetBytes((uint)1).CopyTo(inOptionValues, 0);                 BitConverter.GetBytes((uint)5000).CopyTo(inOptionValues, Marshal.SizeOf(dummy));                 BitConverter.GetBytes((uint)5000).CopyTo(inOptionValues, Marshal.SizeOf(dummy) * 2);                 return inOptionValues;             }         }         ///           /// 设置心跳         ///          private static void SetXinTiao()         {             //byte[] inValue = new byte[] { 1, 0, 0, 0, 0x20, 0x4e, 0, 0, 0xd0, 0x07, 0, 0 };// 首次探测时间20 秒, 间隔侦测时间2 秒             byte[] inValue = new byte[] { 1, 0, 0, 0, 0x88, 0x13, 0, 0, 0xd0, 0x07, 0, 0 };// 首次探测时间5 秒, 间隔侦测时间2 秒             theSocket.Client.IOControl(IOControlCode.KeepAliveValues, KeepAliveTime, null);         }           ///           /// 创建套接字+异步连接函数         ///          ///          private static bool socket_create_connect()         {             IPAddress ipAddress = IPAddress.Parse(remoteHost);             IPEndPoint remoteEP = new IPEndPoint(ipAddress, remotePort);             theSocket = new TcpClient();             theSocket.SendTimeout = 1000;               SetXinTiao();//设置心跳参数               #region 异步连接代码               TimeoutObject.Reset(); //复位timeout事件             try             {                 theSocket.BeginConnect(ipAddress,remotePort, connectedCallback, theSocket);             }             catch (Exception err)             {                 SockErrorStr = err.ToString();                 return false;             }             if (TimeoutObject.WaitOne(10000, false))//直到timeout，或者TimeoutObject.set()             {                 if (IsconnectSuccess)                 {                     return true;                 }                 else                 {                     return false;                 }             }             else             {                 SockErrorStr = "Time Out";                 return false;             }             #endregion         }           ///           /// 同步receive函数         ///          ///          ///          public string socket_receive(byte[] readBuffer)         {             try             {                 if (theSocket == null)                 {                     socket_create_connect();                 }                 else if (!theSocket.Connected)                 {                     if (!IsSocketConnected())                         Reconnect();                 }                   int bytesRec = theSocket.Client.Receive(readBuffer);                   if (bytesRec == 0)                 {                     //warning 0 bytes received                 }                 return Encoding.ASCII.GetString(readBuffer, 0, bytesRec);             }             catch (SocketException se)             {                 //print se.ErrorCode                 throw;             }         }           ///           /// 同步send函数         ///          ///          ///          public bool socket_send(string sendMessage)         {             if (checkSocketState())             {                 return SendData(sendMessage);             }             return false;         }           ///           /// 断线重连函数         ///          ///          private static bool Reconnect()         {             //关闭socket             theSocket.Client.Shutdown(SocketShutdown.Both);               theSocket.Client.Disconnect(true);             IsconnectSuccess = false;               theSocket.Close();               //创建socket             return socket_create_connect();         }           ///           /// 当socket.connected为false时，进一步确定下当前连接状态         ///          ///          private bool IsSocketConnected()         {             #region remarks             /********************************************************************************************              * 当Socket.Conneted为false时， 如果您需要确定连接的当前状态，请进行非阻塞、零字节的 Send 调用。              * 如果该调用成功返回或引发 WAEWOULDBLOCK 错误代码 (10035)，则该套接字仍然处于连接状态；               * 否则，该套接字不再处于连接状态。              * Depending on http://msdn.microsoft.com/zh-cn/library/system.net.sockets.socket.connected.aspx?cs-save-lang=1&cs-lang=csharp#code-snippet-2             ********************************************************************************************/             #endregion               #region 过程             // This is how you can determine whether a socket is still connected.             bool connectState = true;             bool blockingState = theSocket.Client.Blocking;             try             {                 byte[] tmp = new byte[1];                   theSocket.Client.Blocking = false;                 theSocket.Client.Send(tmp, 0, 0);                 //Console.WriteLine("Connected!");                 connectState = true; //若Send错误会跳去执行catch体，而不会执行其try体里其之后的代码             }             catch (SocketException e)             {                 // 10035 == WSAEWOULDBLOCK                 if (e.NativeErrorCode.Equals(10035))                 {                     //Console.WriteLine("Still Connected, but the Send would block");                     connectState = true;                 }                   else                 {                     //Console.WriteLine("Disconnected: error code {0}!", e.NativeErrorCode);                     connectState = false;                 }             }             finally             {                 theSocket.Client.Blocking = blockingState;             }               //Console.WriteLine("Connected: {0}", client.Connected);             return connectState;             #endregion         }           ///           /// 另一种判断connected的方法，但未检测对端网线断开或ungraceful的情况         ///          ///          ///          public static bool IsSocketConnected(Socket s)         {             #region remarks             /* As zendar wrote, it is nice to use the Socket.Poll and Socket.Available, but you need to take into consideration               * that the socket might not have been initialized in the first place.               * This is the last (I believe) piece of information and it is supplied by the Socket.Connected property.               * The revised version of the method would looks something like this:               * from：http://stackoverflow.com/questions/2661764/how-to-check-if-a-socket-is-connected-disconnected-in-c */             #endregion               #region 过程               if (s == null)                 return false;             return !((s.Poll(1000, SelectMode.SelectRead) && (s.Available == 0)) || !s.Connected);               /* The long, but simpler-to-understand version:                     bool part1 = s.Poll(1000, SelectMode.SelectRead);                     bool part2 = (s.Available == 0);                     if ((part1 && part2 ) || !s.Connected)                         return false;                     else                         return true;             */             #endregion         }           ///           /// 异步连接回调函数         ///          ///          static void connectedCallback(IAsyncResult iar)         {             #region <remarks>             /// 1、置位IsconnectSuccess             #endregion </remarks>               lock (lockObj_IsConnectSuccess)             {                 TcpClient client = (TcpClient)iar.AsyncState;                 try                 {                     client.EndConnect(iar);                     IsconnectSuccess = true;                     StartKeepAlive(); //开始KeppAlive检测                 }                 catch (Exception e)                 {                     //Console.WriteLine(e.ToString());                     SockErrorStr = e.ToString();                     IsconnectSuccess = false;                 }                 finally                 {                     TimeoutObject.Set();                 }             }         }           ///           /// 开始KeepAlive检测函数         ///          private static void StartKeepAlive()         {             theSocket.Client.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(OnReceiveCallback), theSocket);         }           ///           /// BeginReceive回调函数         ///          static byte[] buffer = new byte[1024];         private static void OnReceiveCallback(IAsyncResult ar)         {             try             {                 TcpClient peerSock = (TcpClient)ar.AsyncState;                 int BytesRead = peerSock.Client.EndReceive(ar);                 if (BytesRead > 0)                 {                     byte[] tmp = new byte[BytesRead];                     Array.ConstrainedCopy(buffer, 0, tmp, 0, BytesRead);                     if (socketDataArrival != null)                     {                         socketDataArrival(tmp);                     }                 }                 else//对端gracefully关闭一个连接                 {                     if (theSocket.Connected)//上次socket的状态                     {                         if (socketDisconnected != null)                         {                             //1-重连                             socketDisconnected();                             //2-退出，不再执行BeginReceive                             return;                         }                     }                 }                 //此处buffer似乎要清空--待实现 zq                 theSocket.Client.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(OnReceiveCallback), theSocket);             }             catch (Exception ex)             {                 if (socketDisconnected != null)                 {                     socketDisconnected(); //Keepalive检测网线断开引发的异常在这里捕获                     return;                 }             }         }           ///           /// 异步收到消息处理器         ///          ///          private static void socketDataArrivalHandler(byte[] data)         {         }           ///           /// socket由于连接中断(软/硬中断)的后续工作处理器         ///          private static void socketDisconnectedHandler()         {             Reconnect();         }           ///           /// 检测socket的状态         ///          ///          public static bool checkSocketState()         {             try             {                 if (theSocket == null)                 {                     return socket_create_connect();                 }                 else if (IsconnectSuccess)                 {                     return true;                 }                 else//已创建套接字，但未connected                 {                     #region 异步连接代码                       TimeoutObject.Reset(); //复位timeout事件                     try                     {                         IPAddress ipAddress = IPAddress.Parse(remoteHost);                         IPEndPoint remoteEP = new IPEndPoint(ipAddress, remotePort);                         theSocket.Client.BeginConnect(remoteEP, connectedCallback, theSocket);                           SetXinTiao();//设置心跳参数                     }                     catch (Exception err)                     {                         SockErrorStr = err.ToString();                         return false;                     }                     if (TimeoutObject.WaitOne(2000, false))//直到timeout，或者TimeoutObject.set()                     {                         if (IsconnectSuccess)                         {                             return true;                         }                         else                         {                             return false;                         }                     }                     else                     {                         SockErrorStr = "Time Out";                         return false;                     }                       #endregion                 }               }             catch (SocketException se)             {                 SockErrorStr = se.ToString();                 return false;             }         }             ///           /// 同步发送         ///          ///          ///          public static bool SendData(string dataStr)         {             bool result = false;             if (dataStr == null || dataStr.Length < 0)                 return result;             try             {                 byte[] cmd = Encoding.Default.GetBytes(dataStr);                 int n = theSocket.Client.Send(cmd);                 if (n < 1)                     result = false;             }             catch (Exception ee)             {                 SockErrorStr = ee.ToString();                 result = false;             }             return result;         }     } } 程序调用
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading; using System.Threading.Tasks; using System.Windows.Forms;   namespace TcpDisconnectDemo {     public partial class Form1 : Form     {         public Form1()         {             InitializeComponent();               }           Socket_wrapper ssw;         System.Windows.Forms.Timer timer;         private void Form1_Load(object sender, EventArgs e)         {                 ssw = new Socket_wrapper("192.168.83.129", 10000);             Socket_wrapper.socketDataArrival = Socket_wrapper_socketDataArrival;               Socket_wrapper.checkSocketState();               timer = new System.Windows.Forms.Timer();             timer.Interval = 10 * 1000;             timer.Tick += Timer_Tick;             timer.Start();               }         private delegate void SetLabelDelegate(string value);             private void SetText(string value)         {             if (this.InvokeRequired)             {                 SetLabelDelegate d = new SetLabelDelegate(SetText);                 this.Invoke(d, new object[] { value });             }             else             {                 textBox1.Text = value.ToString();             }         }           private void Socket_wrapper_socketDataArrival(byte[] data)         {             string ss = Encoding.ASCII.GetString(data, 0, data.Length);             //Console.WriteLine(ss);             SetText(ss);         }               private void Timer_Tick(object sender, EventArgs e)         {             Socket_wrapper.checkSocketState();         }     } }