How to check if a socket is connected/disconnected in C#?

Question

How can you check if a network socket (System.Net.Sockets.Socket) is still connected if the other host doesn\'t send you a packet when it disconnects (e.g. because it discon

Answer 1

I made an extension method based on this MSDN article. This is how you can determine whether a socket is still connected.

public static bool IsConnected(this Socket client)
{
    bool blockingState = client.Blocking;

    try
    {
        byte[] tmp = new byte[1];

        client.Blocking = false;
        client.Send(tmp, 0, 0);
        return true;
    }
    catch (SocketException e)
    {
        // 10035 == WSAEWOULDBLOCK
        if (e.NativeErrorCode.Equals(10035))
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    finally
    {
        client.Blocking = blockingState;
    }
}