如何在TCP客户端(套接字)上实现VB.NET中的TCP KeepAlive
问题描述:
我想实现TCP KeepAlive以通过运行计时器来检查丢弃的连接。在我的情况下,我有一个TCP客户端(使用套接字类)和第三方服务器(我没有控制它)。 如何在我的TCP客户端上使用TCP KeepAlive以检查连接状态?如何在TCP客户端(套接字)上实现VB.NET中的TCP KeepAlive
目前我已启用TCP KeepAlive选项!
tcpsocket.Connect(IPEndPoint)
tcpSocket.SetSocketOption(SocketOptionLevel.Tcp,SocketOptionName.KeepAlive,1);
搜索互联网上我发现这个过程,应该工作,但我想知道如何我可以用它在我的TCP客户端?
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,请原谅我的编码错误。
答
最后,我设法使用TCP KeepAlive。 因此,为了实现这一点,我刚刚叫mainform_load程序:
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
我已使用Wireshark检查,我注意到了发送的数据包。