private void button_openPort_Click(object sender, EventArgs e) { if (button_open.Text == "Open port") { try { daq32 = new DAQ32serial(comboBox_COM.Text); daq32.packetReceived += new DAQ32serial.onDataPacketReceived(daq32_packetReceived); daq32.packetError += new DAQ32serial.onDataPacketError(daq32_packetError); comboBox_COM.Enabled = false; button_open.Text = "Close port"; } catch (Exception ex) { MessageBox.Show(ex.Message); } } else // if(button_connect.Text == "Disconnect") { daq32.Close(); daq32 = null; comboBox_COM.Enabled = true; button_open.Text = "Open port"; } }