父类和子类的关系、代码例子

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

namespace ConsoleApplication1
{    
    class Program
    {
        static void Main(string[] args)
        {
            //父类
            BaseClass Basefun = new BaseClass();
            Basefun.Basefun();
            //扩展父类方法，注意实例的对象为子类
            BaseClass Subfun = new SubClass();            
            Subfun.Basefun();
            Console.ReadKey();
        }
        class BaseClass
        {
            public virtual void Basefun()
            {
                Console.WriteLine("父类方法");
            }
        }       
        class SubClass:BaseClass
        {
            public override void Basefun()
            {
                Console.WriteLine("子类方法");
            }
        }
    }
}