protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.CategoriesList);

            try
            {
                // Initialize the SampleManager and create the Sample Categories.
                SampleManager.Current.Initialize();
                _sampleCategories         = SampleManager.Current.FullTree.Items.OfType <SearchableTreeNode>().ToList();
                _filteredSampleCategories = _sampleCategories;

                // Set up the custom ArrayAdapter for displaying the Categories.
                var categoriesAdapter = new CategoriesAdapter(this, _sampleCategories);
                _categoriesListView = FindViewById <ExpandableListView>(Resource.Id.categoriesListView);
                _categoriesListView.SetAdapter(categoriesAdapter);
                _categoriesListView.ChildClick   += CategoriesListViewOnChildClick;
                _categoriesListView.DividerHeight = 2;
                _categoriesListView.SetGroupIndicator(null);

                // Set up the search filtering.
                SearchView searchBox = FindViewById <SearchView>(Resource.Id.categorySearchView);
                searchBox.QueryTextChange += SearchBoxOnQueryTextChange;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.CategoriesList);

            try
            {
                // Initialize the SampleManager and create the Sample Categories.
                SampleManager.Current.Initialize();
                _sampleCategories = SampleManager.Current.FullTree.Items.OfType <SearchableTreeNode>().ToList();

                // Remove AR category if device does not support AR.
                try
                {
                    var arSession = new Session(this);
                    _arCompatible = true;
                }
                catch (UnavailableException ex)
                {
                    Console.WriteLine(ex.Message);
                    _arCompatible = false;
                }

                if (!_arCompatible)
                {
                    _sampleCategories.RemoveAll(category => category.Name == "Augmented reality");
                }

                _filteredSampleCategories = _sampleCategories;

                // Set up the custom ArrayAdapter for displaying the Categories.
                var categoriesAdapter = new CategoriesAdapter(this, _sampleCategories);
                _categoriesListView = FindViewById <ExpandableListView>(Resource.Id.categoriesListView);
                _categoriesListView.SetAdapter(categoriesAdapter);
                _categoriesListView.ChildClick   += CategoriesListViewOnChildClick;
                _categoriesListView.DividerHeight = 2;
                _categoriesListView.SetGroupIndicator(null);

                // Set up the search filtering.
                SearchView searchBox = FindViewById <SearchView>(Resource.Id.categorySearchView);
                searchBox.QueryTextChange += SearchBoxOnQueryTextChange;

                // Add a button that brings up settings.
                Button settingsButton = FindViewById <Button>(Resource.Id.settingsButton);
                settingsButton.Click += (s, e) => PromptForKey();

                // Check the existing API key for validity.
                _ = CheckApiKey();
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
        protected override void OnCreate(Bundle bundle)
        {
            base.OnCreate(bundle);

            SetContentView(Resource.Layout.CategoriesList);

            try
            {
                // Initialize the SampleManager and create the Sample Categories
                SampleManager.Current.Initialize();
                _sampleCategories = SampleManager.Current.FullTree.Items.OfType <SearchableTreeNode>().ToList();

                // Set up the custom ArrayAdapter for displaying the Categories.
                var      categoriesAdapter  = new CategoriesAdapter(this, _sampleCategories);
                ListView categoriesListView = FindViewById <ListView>(Resource.Id.categoriesListView);
                categoriesListView.Adapter = categoriesAdapter;

                categoriesListView.ItemClick += CategoriesItemClick;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }