private void selectionChanged(object sender, SelectionChangedEventArgs e)
 {
     if (mainViewArea != null)
     {
         if (cmbRoverType.SelectedIndex == 0)
         {
             // Ev3 Tracked Explor3r
             if (rsEvte == null)
             {
                 rsEvte = new RobotSettings_Ev3TrackedExplor3r();
             }
             mainViewArea.Content = rsEvte;
         }
         if (cmbRoverType.SelectedIndex == 1)
         {
             // IR Scan Tester
             if (irScan == null)
             {
                 irScan = new RobotSettings_IRScanTester();
             }
             mainViewArea.Content = irScan;
         }
         if (cmbRoverType.SelectedIndex == 2)
         {
             // Ev3 Tracked Explor3r Mark II
             if (rsEvte2 == null)
             {
                 rsEvte2 = new RobotSettings_Ev3TrackedExplor3r_MarkII();
             }
             mainViewArea.Content = rsEvte2;
         }
     }
     return;
 }
        public RobotSettings()
        {
            InitializeComponent();

            // Fields initialization
            rsEvte  = new RobotSettings_Ev3TrackedExplor3r();
            rsEvte2 = new RobotSettings_Ev3TrackedExplor3r_MarkII();
            irScan  = new RobotSettings_IRScanTester();
            cmbRoverType.SelectedIndex = 0;
        }