private void AddTileOverlay(TileOverlay tileOverlay) { TileOverlayOptions options = new TileOverlayOptions(); if (tileOverlay is UrlTileOverlay) { options.InvokeTileProvider(new UrlTileOverlayProvider(tileOverlay as UrlTileOverlay)); } tileOverlays.Add(tileOverlay, googleMap.AddTileOverlay(options)); }