private async void MySceneView_MouseLeftDown(object sender, MouseEventArgs e)
        {
            if (edit == true && (type == "line" || type == "area"))
            {
                if (MySceneView.GetCurrentViewpoint(ViewpointType.BoundingGeometry) == null)
                {
                    return;
                }
                _mapViewModel.Clear(type);
                System.Windows.Point screenPoint = e.GetPosition(MySceneView);
                MapPoint             mapPoint    = await MySceneView.ScreenToLocationAsync(screenPoint);

                if (mapPoint.X != 0 && mapPoint.Y != 0 && mapPoint.Z != 0)
                {
                    mapPoint = GeometryEngine.NormalizeCentralMeridian(mapPoint) as MapPoint;
                    mapPoint_list.Add(new MapPoint(mapPoint.X, mapPoint.Y));
                    if (mapPoint_list.Count > 1)
                    {
                        var boatPositions = new PolylineBuilder(SpatialReferences.Wgs84);
                        boatPositions.AddPoint(new MapPoint(mapPoint_list[mapPoint_list.Count - 2].X, mapPoint_list[mapPoint_list.Count - 2].Y));
                        boatPositions.AddPoint(new MapPoint(mapPoint_list[mapPoint_list.Count - 1].X, mapPoint_list[mapPoint_list.Count - 1].Y));
                        var boatRoute = boatPositions.ToGeometry();
                        _mapViewModel.Line(boatRoute, "temp");;
                    }
                }
            }
        }
        private async void MySceneView_PointerMoved(object sender, PointerRoutedEventArgs e)
        {
            try
            {
                // Get the geographic location for the current mouse position.
                MapPoint geoPoint = await MySceneView.ScreenToLocationAsync(e.GetCurrentPoint(MySceneView).Position);

                if (geoPoint == null)
                {
                    return;
                }

                // Update the location distance measurement.
                _distanceMeasurement.EndLocation = geoPoint;
            }
            catch (Exception ex)
            {
                Debug.WriteLine(ex.ToString());
            }
        }