private void TabControl_SelectionChanged(object sender, SelectionChangedEventArgs e) { try { int selectedTabID = tabMain.SelectedIndex; if (selectedTabID < 0) { return; } //contacts tab selected if (selectedTabID.Equals(ConfigureTabNumber)) { //load the ports combo box if (!this.modemIsConnected) { List <string> portsList = new List <string>(); portsList = PortHelper.GetModemPorts(); if (portsList.Count > 0) { cbPortName.ItemsSource = portsList; } else { configureStatusBar.Text = "No modem detected"; } } } } catch (Exception) { } }