ArcGISPortalViewer.ViewModel.SearchViewModel.SearchViewModel C# (CSharp) Method

        public SearchViewModel(INavigationService navigationService)
        {
            // initialize ItemClick RelayCommand
            ItemClickCommand = new RelayCommand<object>((e) =>
            {
                // handle the type of EventArgs passed
                ArcGISPortalItem portalItem = null;
                if (e == null)
                    portalItem = null;
                // the GridView sends ItemClickEventArgs
                else if (e is ItemClickEventArgs)
                    portalItem = ((ItemClickEventArgs)e).ClickedItem as ArcGISPortalItem;                

                // send clicked item via a message to other ViewModels who
                // are registered with ChangeItemSelectedMessage
                Messenger.Default.Send<ChangeItemSelectedMessage>(new ChangeItemSelectedMessage() { Item = portalItem });

                //Use the navigation service to navigate to the page showing the item details
                navigationService.Navigate(App.ItemPageName, portalItem);
            });

            // initialize SelectItemCommand RelayCommand
            SelectItemCommand = new RelayCommand<object>((e) =>
            {
                // handle the type of EventArgs passed
                ArcGISPortalItem portalItem = null;
                if (e == null)
                    portalItem = null;

                // the GridView sends SelectionChangedEventArgs
                else if (e.GetType() == typeof(SelectionChangedEventArgs))
                    portalItem = ((SelectionChangedEventArgs)e).AddedItems.FirstOrDefault() as ArcGISPortalItem;

                SelectedPortalItem = portalItem;
                AppViewModel.CurrentAppViewModel.SelectedPortalItem = SelectedPortalItem;
            });

            // initialise SelectSortFieldCommand RelayCommand
            SelectSortFieldCommand = new RelayCommand<object>((obj) =>
            {
                if (obj != null && obj is ComboBoxItem)
                {
                    var content = ((ComboBoxItem)obj).Content;
                    if (content != null)
                        CurrentSortField = GetCurrentSortField(content.ToString());
                    SortResults(CurrentSortField);
                }
            });

            // initialise SelectSearchDomainCommand RelayCommand
            SelectSearchDomainCommand = new RelayCommand<object>((obj) =>
            {
                if (obj is ComboBoxItem)
                {
                    var content = ((ComboBoxItem)obj).Content;
                    if (content == null) return;
                    var searchDomain = content.ToString();
                    if (string.IsNullOrEmpty(searchDomain)) return;
                    PortalService.CurrentPortalService.OrganizationResultsOnly = searchDomain == (string) Application.Current.Resources["SearchOrganization"];
                    if (SearchResults != null && SearchResults.IsEmpty) 
                        SearchResults= null;
                    // refresh search results            
                    UpdateResults();
                }
            });
        }