private void WpfMap_Loaded(object sender, RoutedEventArgs e)
        {
            wpfMap1.MapUnit = GeographyUnit.DecimalDegree;
            wpfMap1.CurrentExtent = new RectangleShape(-133.2515625, 89.2484375, 126.9046875, -88.290625);
            wpfMap1.MapClick += new System.EventHandler<MapClickWpfMapEventArgs>(wpfMap1_MapClick);


            WorldMapKitWmsWpfOverlay worldMapKitOverlay = new WorldMapKitWmsWpfOverlay();
            wpfMap1.Overlays.Add(worldMapKitOverlay);
            wpfMap1.Refresh();


        }

        void wpfMap1_MapClick(object sender, MapClickWpfMapEventArgs e)
        {
            Vertex point = new Vertex(e.WorldX, e.WorldY);
            PolygonShape polygon = new PolygonShape(wpfMap1.EditOverlay.EditShapesLayer.InternalFeatures[0].WellKnownBinary);
            PolygonShape newPolygon = polygon.CloneDeep() as PolygonShape;
            newPolygon.OuterRing.Vertices[2] = point;

            wpfMap1.EditOverlay.EditShapesLayer.InternalFeatures[0].WellKnownBinary = newPolygon.GetWellKnownBinary();
            wpfMap1.EditOverlay.ExistingControlPointsLayer.InternalFeatures[2].WellKnownBinary = new PointShape(point).GetWellKnownBinary();
            wpfMap1.Refresh(wpfMap1.EditOverlay);
        }