为什么不能直接调用DbContext.ObjectContext 获取属性呢？

public interface IA
    {
        void Show();
    }

    public interface IB
    {
        void Show();
    }

    public abstract class AB
    {
        public abstract void Show1();
    }

    public class D : AB, IA, IB
    {
        public void Show()
        {
            Console.WriteLine("concrete show");
        }

        void IA.Show()
        {
            Console.WriteLine("implement IA");
        }

        void IB.Show()
        {
            Console.WriteLine("implement IB");
        }

        public override void Show1()
        {
            Console.WriteLine("D implement AB class");
        }
    }

var d = new D();
            d.Show();

            ((IA)d).Show();

            ((IB)d).Show();