Question

Hi I am designing an application using WPF, EF and MVVM (.NET4.0).

I face issue with freezing UI when I’m binding data. I think this is because of lazy loading.

MVVM:

        ThreadPool.QueueUserWorkItem(state =>
        {
                IsProgressBarVisible(true);

                var service = Context.SomeModel.ToList();
                BgServiceCompleted(service);
        });

XAML:

"{Binding OrderItemViews.SOmeModel_A.SomeModel_B.SOmeField}"
"{Binding OrderItemViews.Country.Name}"

Some Model:

public class SomeModel_A
{
    public int Id { get; set; }
    ....        
    public int SomeB_Id { get; set; }
    public virtual SomeModel_B SomeModel_B { get; set; }
}

I found a solution for this problem.

1) setting the IsAsync-Property in the ItemsSource-Binding.

"{Binding OrderItemViews.SOmeModel_A.SomeModel_B.SOmeField, IsAsync=true}"

The interface does not freeze, but the value appears after a while time. This will confuse some users.

2) using Include for loading include data.
For instance:

Context.SomeModel.Include(a => a.SomeModel2).Load();

but in my case Context doesn’t have Include. Why?

Which the best way to solve this problem?

Could you please give me a guidance on how should I do that or any useful resource I can read and learn about it?
Thanks

Answer 1

Include is not part of the standard libraries, you have to add using System.Data.Entity;. Failing that, what is the type returned by Context.SomeModel?