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

Thank you also for answers. I faced similar issue until today. I used the Andrii Omelchenko solution and helped a lot but not 100%. I saw that the cause for hanging serial port is the reception event handler. Before stopping serial port, uninstall reception event handler.

try
        {
            serialPort.DtrEnable = false;
            serialPort.RtsEnable = false;
            serialPort.DataReceived -= serialPort_DataReceived;
            Thread.Sleep(200);
            if (serialPort.IsOpen == true)
            {
                serialPort.DiscardInBuffer();
                serialPort.DiscardOutBuffer();
                serialPort.Close();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }