为什么 IAsyncResult.AsyncWaitHandle.WaitOne 在 wifi 没有 inte.net 连接且移动数据已打开时返回 false？ (XAMARIN)

Question

I'm trying to do a sync with my custom device via wifi connection. Everything works fine when my mobile data is turned off, but when it's turned on it won't work (because my custom device has no connection to the inte.net).

This is where the problem happens:

stateSuccess = true;
tcpclnt = new TcpClient();
IAsyncResult ar = tcpclnt.BeginConnect(ip, port, new AsyncCallback(connectCallback), stateSuccess);
int timeout = 3000;
stateSuccess = ar.AsyncWaitHandle.WaitOne(timeout, false);

when I have mobile data turned on stateSuccess = false , but when mobile data is turned off stateSuccess = true . I'm always connected over wifi to my custom device.

My connectCallback is:

private void connectCallback(IAsyncResult ar)
        {
            var stateSuccess = (Boolean)ar.AsyncState;

            try
            {
                tcpclnt.EndConnect(ar);
            }
            catch (Exception exc)
            {
                //handle
            }

            try
            {
                if (tcpclnt != null && tcpclnt.Connected && stateSuccess)
                    return;

                tcpclnt.Close();
            }
            catch (Exception exc)
            {
                if (tcpclnt != null)
                    tcpclnt.Close();
            }
        }

I think the problem is somewhere in it chosing the wrong.network. How can I force it to use wifi.network even thou the wifi has no inte.net connection?

Answer 1

The devices do not care nor discriminate the lower-level base-band radio scanning (we're talking about telephony here), that is left to the actual radio firmware to deal with.

If you dont want to use WIFI, turn it off. But if you want to force use WIFI, just turn your cellular data off

Edit: I just found a workaround to this that works ONLY for Android: https://stackoverflow.com/a/56590566/11104068