public Window1()
        {
            InitializeComponent();

            ObservableCollection <MapArr> mapCtrl = new ObservableCollection <MapArr>();

            // 1
            {
                GMapControl map = new GMapControl();
                map.MapProvider = GMapProviders.OpenStreetMap;
                map.MinZoom     = 4;
                map.MaxZoom     = map.MinZoom + 3;
                map.Zoom        = map.MinZoom;
                mapCtrl.Add(new MapArr(map, "Holand"));
            }

            // 2
            {
                GMapControl map = new GMapControl();
                map.MapProvider = GMapProviders.OpenStreetMap;
                map.MinZoom     = 4;
                map.MaxZoom     = map.MinZoom + 3;
                map.Zoom        = map.MinZoom;
                mapCtrl.Add(new MapArr(map, "New York"));
            }

            // 3
            {
                GMapControl map = new GMapControl();
                map.MapProvider = GMapProviders.OpenStreetMap;
                map.MinZoom     = 4;
                map.MaxZoom     = map.MinZoom + 3;
                map.Zoom        = map.MinZoom;
                mapCtrl.Add(new MapArr(map, "Lithuania"));
            }

            // main
            UserMap.MapProvider = GMapProviders.GoogleMap;
            UserMap.MinZoom     = 5;
            UserMap.MaxZoom     = 13;
            UserMap.Zoom        = 5;
            UserMap.SetCurrentPositionByKeywords("Leuven");

            // add all maps
            locations.ItemsSource = mapCtrl;
        }