using System;
using System.Collections.Generic;
using System.Text;namespace 抽象方法练习
{class Program{static void Main(string[] args){Computer dev = new Computer();MP3 mp3 = new MP3();YDDisk yd = new YDDisk();dev.dev = yd;dev.dev.Read();//输入是移动硬盘在…
using System;namespace 类型转换
{class Program{static void Main(string[] args){try{Student s1 = new Student();Person p = new Person();//Student s2 = (Student)p;//这样父类转子类,虽然不报错,但运行时会出错Student s = p as Student;//这样转,如果成功则有返回值…