C# Winform freezing on SerialPort.Close

Question

I have a winform program that does some asynchronous IO on a SerialPort. However, I\'m periodically running into an issue with the program freezing on the SerialPo

Answer 1

Workaround by nobugz user from here:

1) add System.Threading.Thread CloseDown; field to form with serial port serialPort1;

2) implement method CloseSerialOnExit() with serialPort1 close steps:

private void CloseSerialOnExit()
{

    try
    {
        serialPort1.DtrEnable = false;
        serialPort1.RtsEnable = false;
        serialPort1.DiscardInBuffer();
        serialPort1.DiscardOutBuffer();
        serialPort1.Close();
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);

    }
}

3) when you need to close serialPort1 (e.g. on button click) call CloseSerialOnExit() in new thread to avoid hang:

...
CloseDown = new System.Threading.Thread(new System.Threading.ThreadStart(CloseSerialOnExit)); 
CloseDown.Start();
...

and that's it!