c# 继承

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

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            A a = new A();
            Console.WriteLine(a.ToString());
            Console.WriteLine(a.ToString2());

            a = new B();
            Console.WriteLine(a.ToString());
            Console.WriteLine(a.ToString2());
            Console.WriteLine(((B)a).ToString2());
            Console.ReadLine();
        }
    }

    class A
    {
        public override string ToString()
        {
            return "A.tostring()";
        }
        public string ToString2()
        {
            return "A.tostring2()";

        }
    }

    class B : A 
    {
        public override string ToString()
        {
            return "B.tostring()";
        }
        public new  string ToString2()
        {
            return "B.tostring2()";

        }
    }

}

结果:

A.tostring()

A.tostring2()

B.tostring()

A.tostring2()

B.tostring2()