继承的基本实现

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

namespace ConsoleApp1
{

    public abstract class A
    {
        public abstract int num();
        public int anum;
        public A()
        {
            anum = 12;
        }
        public abstract String astr
        {
            get;set;
        }

    }

    public class B : A
    {
        public override int num()
        {
            Console.WriteLine("抽象方法的实现");
            return 0;
        }

        public override String astr
        {
            get { return "抽象属性"; }
            set { value = "设置值"; }
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            B b = new B();
            Console.WriteLine(b.anum);
            Console.WriteLine(b.num());
            Console.WriteLine(b.astr);

            Console.ReadKey();


        }
    }
}

结果:

12
抽象方法的实现
0
抽象属性