private void listBox1_SelectedValueChanged(object sender, EventArgs e) { if (listBox1.SelectedItem == null) { return; } string icao = listBox1.SelectedItem.ToString(); ADSBPositionMessage positionMessage = viewModel.GetPositionMessage(icao); if (positionMessage != null) { textBoxAltitude.Text = positionMessage.Altitude.ToString(); } else { textBoxAltitude.Text = "No message available"; } ADSBVelocityMessage velocityMessage = viewModel.GetVelocityMessage(icao); if (velocityMessage != null) { textBoxSpeed.Text = velocityMessage.Speed.ToString(); } else { textBoxSpeed.Text = "No message available"; } ADSBIdentificationMessage idMessage = viewModel.GetIdentificationMessage(icao); if (idMessage != null) { textBoxAircraftID.Text = idMessage.AircraftID.ToString(); } else { textBoxAircraftID.Text = "No message available"; } }