接口，抽象类，继承与多态性的使用

演示代码:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    public class Program
    {
        private static void Main(string[] args)
        {

            ITestzh itestzh = new Testzh();
            ITestzh itestdemo = new TestDemo();
            itestzh.Insert();   //输出“子类重写父类的Insert方法”
            itestdemo.Insert(); //输出”用new隐藏父类的Inser方法“

            TestBase t1 = new Testzh();
            TestBase t2 = new TestDemo();
            t1.Insert();  //输出“子类重写父类的Insert方法”
            t2.Insert();  //输出”基类统一实现Insert方法“
            //注意 t2.Insert()与itestdemo.Insert()输出的区别
            Console.ReadKey();
        }
    }
    //借口统一规范
    interface ITest
    {
        /// <summary>
        /// 插入方法
        /// </summary>
        void Insert();
    }
    /// <summary>
    /// 统一的实体基类
    /// 子类共同的操作逻辑
    /// </summary>
    abstract class TestBase : ITest
     {

         #region ITest 成员
 
         public virtual void Insert()
         {
             Console.WriteLine("基类统一实现Insert方法");
         }
 
         #endregion
     }

    //声明借口实现ITest借口
    interface ITestzh:ITest{}
     /// <summary>
     /// Testzh实体操作
     /// </summary>
     class Testzh:TestBase,ITestzh
    {
       //重写父类的Insert方法
        public override void Insert()
        {
            Console.WriteLine("子类重写父类的Insert方法");
        }
    }

     class TestDemo : TestBase, ITestzh
     {
         public new void Insert()
         {
             Console.WriteLine("用new隐藏父类的Inser方法");
         }
     }

}