MissionPlanner.SerialInjectGPS.BUT_connect_Click C# (CSharp) Method

        private void BUT_connect_Click(object sender, EventArgs e)
        {
            if (comPort.IsOpen)
            {
                threadrun = false;
                comPort.Close();
                BUT_connect.Text = Strings.Connect;
                try
                {
                    basedata.Close();

                    basedata = null;
                }
                catch
                {
                }
            }
            else
            {
                status_line3 = null;

                try
                {
                    switch (CMB_serialport.Text)
                    {
                        case "NTRIP":
                            comPort = new CommsNTRIP();
                            CMB_baudrate.SelectedIndex = 0;
                            ((CommsNTRIP) comPort).lat = MainV2.comPort.MAV.cs.lat;
                            ((CommsNTRIP) comPort).lng = MainV2.comPort.MAV.cs.lng;
                            ((CommsNTRIP) comPort).alt = MainV2.comPort.MAV.cs.altasl;
                            break;
                        case "TCP Client":
                            comPort = new TcpSerial();
                            CMB_baudrate.SelectedIndex = 0;
                            break;
                        case "UDP Host":
                            comPort = new UdpSerial();
                            CMB_baudrate.SelectedIndex = 0;
                            break;
                        case "UDP Client":
                            comPort = new UdpSerialConnect();
                            CMB_baudrate.SelectedIndex = 0;
                            break;
                        default:
                            comPort = new SerialPort();
                            comPort.PortName = CMB_serialport.Text;
                            break;
                    }

                    Settings.Instance["SerialInjectGPS_port"] = CMB_serialport.Text;
                    Settings.Instance["SerialInjectGPS_baud"] = CMB_baudrate.Text;
                }
                catch
                {
                    CustomMessageBox.Show(Strings.InvalidPortName);
                    return;
                }
                try
                {
                    comPort.BaudRate = int.Parse(CMB_baudrate.Text);
                }
                catch
                {
                    CustomMessageBox.Show(Strings.InvalidBaudRate);
                    return;
                }
                try
                {
                    comPort.ReadBufferSize = 1024*64;

                    comPort.Open();

                    try
                    {
                        basedata = new BinaryWriter(new BufferedStream(
                            File.Open(
                                Settings.Instance.LogDir + Path.DirectorySeparatorChar +
                                DateTime.Now.ToString("yyyy-MM-dd HH-mm-ss") + ".gpsbase", FileMode.CreateNew,
                                FileAccess.ReadWrite, FileShare.None)));
                    }
                    catch (Exception ex2)
                    {
                        CustomMessageBox.Show("Error creating file to save base data into " + ex2.ToString());
                    }
                }
                catch (Exception ex)
                {
                    CustomMessageBox.Show("Error Connecting\nif using com0com please rename the ports to COM??\n" +
                                          ex.ToString());
                    return;
                }

                // inject init strings - m8p
                if (chk_m8pautoconfig.Checked)
                {
                    this.LogInfo("Setup M8P");
                    ubx_m8p.SetupM8P(comPort, basepos, int.Parse(txt_surveyinDur.Text, CultureInfo.InvariantCulture),
                        double.Parse(txt_surveyinAcc.Text, CultureInfo.InvariantCulture));
                }

                t12 = new System.Threading.Thread(new System.Threading.ThreadStart(mainloop))
                {
                    IsBackground = true,
                    Name = "injectgps"
                };
                t12.Start();

                BUT_connect.Text = Strings.Stop;

                msgseen.Clear();
                bytes = 0;
            }
        }