Get a List<T> from EntityQuery or EntitySet

[Ala eddine]

public

 

public static IList<object> GenerateItems()
        {

            ModuleContext _context = new ModuleContext();
            EntityQuery<Fonctionnalite> q = _context.GetFonctionnalitesByModuleQuery(1);
            LoadOperation<Fonctionnalite> op = _context.Load(q);

            var result = new ObservableCollection<object>();

            foreach (var f in op.Entities.ToArray())
            {
                var item = new MainPageViewModel();
                item.Nom = f.Libelle;
                item.id = f.idFonctionnalite;
                foreach (var sf in f.SousFonctionnalites.ToArray())
                {
                    var child = new MainPageViewModel();
                    child.id = sf.idSousFonctionnalite;
                    child.Nom = sf.Libelle;
                    item.RelatedItems.Add(child);
                }
                result.Add(item);
            }
            return result;
        }

 
I want to display a Hierarchical Data in RadPanelBar form the entities Fonctionnalite and SousFoxtionnalite
( a Fonctionnalite has many SousFonctionnalite ) but i can't get a list from the Entityset<Fonctionnalite> !

[Tina Stancheva]

Hi Ala,

This is probably a timing issue - when you start traversing the LoadOperation Entities collection, it's probably not yet generated. This is why it's better to implement your logic after the operation has completed. For that purpose you can handle the LoadOperation.Completed event:

public partial class MainPage : UserControl
{
    public MainPage()
    {
        InitializeComponent();

        NorthwindContext _northwindContext = new NorthwindContext();
        EntityQuery<Customer> q = _northwindContext.GetCustomersQuery();
        _northwindContext.Load(q).Completed += new EventHandler(op_Completed);
    }

    public static IList<object> GenerateItems(LoadOperation<Customer> op)
    {

        var result = new ObservableCollection<object>();

        foreach (var cust in op.Entities.ToArray())
        {
            var item = new MainPageViewModel();
            item.Name = cust.CompanyName;
            item.Id = cust.CustomerID;
            foreach (var ord in cust.Orders.ToArray())
            {
                var child = new MainPageViewModel();
                child.Id = ord.OrderID.ToString();
                child.Name = ord.ShipCountry;
                item.RelatedItems.Add(child);
            }
            result.Add(item);
        }
        return result;
    }

    private void op_Completed(object sender, EventArgs e)
    {
        xPanelBar.ItemsSource = GenerateItems(sender as LoadOperation<Customer>);
    }

I attached a sample solution demonstrating this approach. I hope it will get you started. Let us know if we can further assist you.

Regards,
Tina Stancheva
the Telerik team