Xceed DataGrid QueryableSource 및 DbContext

Question

문서처럼 DataGridVirtualizingQueryableCollectionViewSource를 구현하려고합니다. http://doc.xceedsoft.com/products/xceedwpfdatagrid/Xceed.Wpf.DataGrid.v4.5~Xceed.Wpf.DataGrid.DataGridVirtualizingQueryableCollectionViewSource.html
ObjectContext API를 사용하는 것이 정상입니다.
그러나 DbContext API를 사용하면 셀 내용이 표시되지 않습니다.
누구에게도이 사실을 알 수 있습니까? 아래

/// <summary> 
/// WITH THIS WORKS. 
/// </summary> 
public partial class AdventureWorksEntities : ObjectContext 

/// <summary> 
/// WITH THIS DOES NOT WORK. 
/// </summary> 
public partial class AdventureWorksEntities : DbContext 

내 소스 :

<Grid xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"> 
    <Grid.Resources> 

     <xcdg:DataGridVirtualizingQueryableCollectionViewSource 
      x:Key="cvs_queryableSource" 
      QueryableSource="{Binding Path=QueryableSource}"/> 

    </Grid.Resources> 
    <xcdg:DataGridControl ItemsSource="{Binding Source={StaticResource cvs_queryableSource}}"> 
    </xcdg:DataGridControl> 
</Grid> 

public partial class MainWindow : Window 
{ 
    public MainWindow() 
    { 
     this.DataContext = this; 
     InitializeComponent(); 
    } 

    public IQueryable QueryableSource 
    { 
     get 
     { 
      if (m_queryable == null) 
      { 
       m_northwind = new AdventureWorksEntities(); 
       m_queryable = m_northwind.Contact; 
      } 
      return m_queryable; 
     } 
    } 

    private AdventureWorksEntities m_northwind; 
    private IQueryable m_queryable; 
} 

감사합니다!

Answer 1

이유는 모르겠지만 간단한 쿼리를 사용하면 OrderBy가 문제를 해결합니다.

public IQueryable QueryableSource 
{ 
    get 
    { 
     if (m_queryable == null) 
     { 
      m_northwind = new AdventureWorksEntities(); 
      m_queryable = m_northwind.Contact.OrderBy(p => p.SomeField); 
     } 
     return m_queryable; 
    } 
} 

다시 한번 감사드립니다!