Tcp连接保持活动状态

Question

我正在创建一个客户端服务器应用程序。服务器已经设计好，等待从客户端连接。现在在客户机部分中，我希望在应用程序的整个生命周期中保持连接活动，并且只有当主客户机应用程序关闭或关闭或者服务器关闭它时，连接才会关闭。

socket.SetSocketOption(SocketOptionLevel.Tcp, SocketOptionName.KeepAlive, true);

public TCPStreamDevice(string RemoteIPAddress, int RemotePort, string SourceIPAddress, int SourcePortNo)        
{
    mIpAddress = RemoteIPAddress;
    mPort = RemotePort;

    mClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
    System.Net.IPEndPoint LocalEndPoint = new System.Net.IPEndPoint(System.Net.IPAddress.Parse(SourceIPAddress), SourcePortNo);

    mClient.Bind(LocalEndPoint);

    mDataReceivedCallback = new AsyncCallback(DataReceivedTCPCallback_Handler);
    mBuffer = new byte[1024];
    Description = new DeviceDescription();
}

在处理程序中我有：

private void DataReceivedTCPCallback_Handler(IAsyncResult ar)
{
    try
    {
        Socket client = (Socket)ar.AsyncState;
        int bytesReceived = client.EndReceive(ar);

        if (bytesReceived > 0)
        {
            //to know transport level errors
            //EngineInterface.reponseReceived(mBuffer, false);

            ReceiveCallBackFunc(mBuffer, bytesReceived);

            client.BeginReceive(mBuffer, 0, 1024, SocketFlags.None, DataReceivedTCPCallback_Handler, client);
        }
        else
        {
            //disconnect
            /* when there is no datapacket  means no TCP connection is alive now (how can i keep Tcp alive here) */
        }
    }
}

Answer 1

在对SetSocketOption()的调用中，KeepAlive在SocketOptionLevel.tcp级别无效，请改用SocketOptionLevel.Socket。

SetSocketOption（SocketOptionLevel.Socket,SocketOptionName.KeepAlive,true)；