.net - 如何在TCP Client(socket)上的VB.NET中实现TCP KeepAlive

Question

我想实现TCP KeepAlive，以便通过运行计时器检查断开的连接。

就我而言，我有一个TCP客户端(使用套接字类)和一个第三方服务器(我对此没有控制权)。
如何在我的TCP客户端上使用TCP KeepAlive来检查连接状态？

目前，我已启用TCP KeepAlive选项!

tcpsocket.Connect(IPEndPoint)
tcpSocket.SetSocketOption(SocketOptionLevel.Tcp,SocketOptionName.KeepAlive,1);

在Internet上搜索时，我发现此程序应该可以工作，但是我想知道如何在TCP客户端中使用它？

Private Shared Function SetKeepAlive(ByRef tcpSocket As Socket, ByVal keepAliveTime As UInteger, ByVal keepAliveInterval As UInteger) As Boolean
  ' Pack three params into 12-element byte array; not sure about endian issues on non-Intel
  Dim SIO_KEEPALIVE_VALS(11) As Byte
  Dim keepAliveEnable As UInteger = 1
  If (keepAliveTime = 0 Or keepAliveInterval = 0) Then keepAliveEnable = 0
  ' Bytes 00-03 are 'enable' where '1' is true, '0' is false
  ' Bytes 04-07 are 'time' in milliseconds
  ' Bytes 08-12 are 'interval' in milliseconds
  Array.Copy(BitConverter.GetBytes(keepAliveEnable),  0, SIO_KEEPALIVE_VALS, 0, 4)
  Array.Copy(BitConverter.GetBytes(keepAliveTime),   0, SIO_KEEPALIVE_VALS, 4, 4)
  Array.Copy(BitConverter.GetBytes(keepAliveInterval), 0, SIO_KEEPALIVE_VALS, 8, 4)

  Try
   Dim result() As Byte = BitConverter.GetBytes(CUInt(0)) ' Result needs 4-element byte array?
   tcpSocket.IOControl(IOControlCode.KeepAliveValues, SIO_KEEPALIVE_VALS, result)
  Catch e As Exception
   Return False
  End Try
  Return True
 End Function

任何帮助，将不胜感激。

PS:我是编程新手，所以请原谅我的编码错误。

Answer 1

最后，我设法使用了TCP KeepAlive。
因此，为了实现此目的，我刚刚在mainform_load过程中进行了调用:

        tcpSocket = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
        tcpSocket.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.KeepAlive, True)
        SetKeepAlive(tcpSocket, keepalivetime, keepaliveinterval)
        Try
            tcpSocket.Connect(ipEndPoint)
        Catch e As SocketException
            ...
        End Try

我已经与WireShark核对过，并且注意到发送的软件包。