public override void OnBackPressed()
 {
     if (_selectedMainCategory == null)
     {
         base.OnBackPressed();
     }
     else
     {
         _selectedMainCategory = null;
         _adapter.NotifyDataSetChanged();
     }
 }
        public void OnReceivedSearchResults(IList <SKSearchResult> results)
        {
            BuildResultsMap(results);

            _operationInProgressLabel.Visibility = ViewStates.Gone;
            _listView.Visibility = ViewStates.Visible;

            _adapter = new ResultsListAdapter(this);

            _listView.Adapter = _adapter;

            _listView.ItemClick += (s, e) =>
            {
                if (_selectedMainCategory == null)
                {
                    _selectedMainCategory = SKCategories.SKPOIMainCategory.ForInt(MainCategories[e.Position]);
                    _adapter.NotifyDataSetChanged();
                }
            };
        }