/// <summary>
 /// Method to be executed when user clicks on any photo.
 /// Argument is the clicked photo.
 /// </summary>
 private void PhotoClicked(Photo photo)
 {
     if (photo == null) return;
     var galleryParameters = new GalleryNavigationParameters()
     {
         Index = PhotosCollection.IndexOf(photo),
         Photos = PhotosCollection.ToList()
     };
     //The purpose of serialzing here is to pass simple type that navigation state can recover after suspension
     //otherwise we could use pass them as strongly typed
     _navigationService.NavigateByPage<GalleryView>(JsonConvert.SerializeObject(galleryParameters));
 }
 private void ShowMap(Photo photo)
 {
     if (photo == null) return;
     //Navigation to Map
     //The purpose of serialzing here is to pass simple type that navigation state can recover after suspension
     //otherwise we could use pass them as strongly typed
     _navigationService.NavigateByPage<MapView>(JsonConvert.SerializeObject(photo));
 }