温故知新：接口的隐式实现与显式实现

using System;

namespace InterfaceTest
{
    class Program
    {
        static void Main(string[] args)
        {
            TestAB ab = new TestAB();
            ab.HelloWorld(); //Hello World!           

            IB b = ab as IB;
            b.HelloWorld(); //IB.HelloWorld!

            IA a = ab as IA;
            a.HelloWorld(); //IA.HelloWorld!

            Console.Read();
        }
    }

    //IA的接口定义
    interface IA
    {
        void HelloWorld();
    }

    //IB的接口定义
    interface IB
    {
        void HelloWorld();
    }

    class TestAB : IA, IB
    {
        //隐式实现IA与IB的HelloWorld方法
        public void HelloWorld()
        {
            Console.WriteLine("Hello World!");            
        }

        //显式实现IB接口的HelloWorld方法
        void IB.HelloWorld()
        {
            Console.WriteLine("IB.HelloWorld!");
        }

        //显式实现IA接口的HelloWorld方法
        void IA.HelloWorld()
        {
            Console.WriteLine("IA.HelloWorld!");
        }       
    }
}