如何在网格上使用EntityFramework生成的DbSet和DataContext？

Question

问题

我有一个EntityFramework生成的DbSet，我从Grid.DataContext绑定到

myEntities = new MyEntities();
grMain.DataContext = myEntities.GalleryLists.ToList();

所有人都是华丽而花花公子，但List不是一个可观察的收藏品。我实际上（可能）想要这样做：

grMain.DataContext = myEntities.GalleryLists.Local; //myEntities.GalleryLists //???;

但后一个我想要工作的选项，在这个Grid中给了我空的ListBox，而前一个可以完美地工作。那么我做错了什么？

更多详情

Grid使用ListBoxes以下列方式定义（设置用于绑定到Gallery列表）：

<Grid Name="grMain">
   <!-- Column definitions and such -->
    <ListBox Name="lbxLists" Grid.Row="1" Grid.Column="0" 
ItemsSource="{Binding}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBlock Text="{Binding Path=GalleryName}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
    <ListBox Name="lbxItems" Grid.Row="1" Grid.Column="1" 
             ItemsSource="{Binding ElementName=lbxLists, Path=SelectedItem.GalleryItems}">
        <ListBox.ItemTemplate>
            <DataTemplate>
                <TextBox Text="{Binding Path=GalleryItemPath}"/>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>
</Grid>

实体框架生成的对象如下所示：

public partial class TiresiasEntities : DbContext
{
    public TiresiasEntities()
        : base("name=TiresiasEntities")
    {
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        throw new UnintentionalCodeFirstException();
    }

    public virtual DbSet<GalleryItem> GalleryItems { get; set; }
    public virtual DbSet<GalleryList> GalleryLists { get; set; }
}
public partial class Gallery
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public GalleryList()
    {
        this.GalleryItems = new HashSet<GalleryItem>();
    }

    public int GalleryID { get; set; }
    public string GalleryName { get; set; }
    public byte IsSystemGallery { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<GalleryItem> GalleryItems { get; set; }
}

感谢您的任何建议。

Answer 1

您可能需要在绑定到DbSet.Local之前调用IQueryable.Load（）：

myEntities = new MyEntities();
myEntities.GalleryLists.Load();
grMain.DataContext = myEntities.GalleryLists.Local;