AnyPlace.MainPage.btn_source_Click C# (CSharp) Method

        void btn_source_Click(object sender, RoutedEventArgs e)
        {
            _externalSource = false;
            if (Mymap.Layers.Contains(floorPoisDetail))
            {
                Mymap.Layers.Remove(floorPoisDetail);
                floorPoisDetail.Clear();
            }
            if (Mymap.Layers.Contains(indoorLayer))
                Mymap.Layers.Remove(indoorLayer);

            if (Mymap.Layers.Contains(_sourceLayer))
                Mymap.Layers.Remove(_sourceLayer);

            // clear directions
            if (GetRoute.Count != 0)
            {
                GetRoute.Clear();
                if (_myMapRoute != null)
                {
                    routedetails_layer.Clear();
                    Mymap.RemoveRoute(_myMapRoute);
                    Mymap.Layers.Remove(routedetails_layer);
                    routeNavDetails.Clear();
                }
            }


            MoveViewWindow(30);

            if (directions_grid.Visibility == Visibility.Visible)
            {
                directions_grid.Visibility = Visibility.Collapsed;
                stackpanelClose();
            }

            ApplicationBar.IsVisible = true;

            _sourcePoi = true;

            var button = sender as Button;
            var context = button.DataContext as PoiTap;
            _floorPoiFrom = context.poiId;
            _floorPoiFromNumber = context.poiFloor;

            if (Mymap.MapElements.Contains(_polyline))
            {
                Mymap.MapElements.Remove(_polyline);
                BuildingSourcePoi();
            }
            else
            {
                var imageMylocation = new Image
                {
                    Source = new BitmapImage(new Uri("/Assets/source.png", UriKind.Relative))
                };
                _sourceOverlay = new MapOverlay();
                _sourceLayer = new MapLayer();
                _sourceOverlay.Content = imageMylocation;
                _sourceOverlay.GeoCoordinate = context.coordinate;
                _sourceOverlay.PositionOrigin = new Point(0.5, 1);
                _sourceLayer.Add(_sourceOverlay);
                Mymap.Layers.Add(_sourceLayer);
            }

        }