如何创建一个嵌套的GridView来编辑EF Code First关系？

asp:GridView

public class Context : DbContext
{         
    public DbSet<Animal> Animals { get; set; }
    public DbSet<Tag> Tags { get; set; }
}

public class Animal
{
    public int AnimalID { get; set; }
    public string Name { get; set; }
    public virtual IEnumerable<Tag> Tags { get; set; }
}

public class Tag
{
    public int TagID { get; set; }
    public string Name { get; set; }
}

asp:Gridview

Animal

<asp:GridView runat=\"server\" DataSourceID=\"animalDataSource\" DataKeyNames=\"AnimalID\" AutoGenerateColumns=\"false\">   
    <Columns>
        <asp:BoundField DataField=\"Description\" HeaderText=\"Description\" />
        <asp:CommandField ShowCancelButton=\"true\" ShowEditButton=\"true\" ShowDeleteButton=\"true\" />
    </Columns>
</asp:GridView>

protected void DataSource_ContextCreating(object sender, EntityDataSourceContextCreatingEventArgs e) 
{    
        var context = new Context();
        e.Context = ((IObjectContextAdapter)context).ObjectContext; } 
}

Animal

Tag