2017-06-04 12:01 3639

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…