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

namespace 里氏转换
{
    class Program
    {
        static void Main(string[] args)
        {
            //1）子类可以赋值给父类:如果有一个地方需要一个父类作为参数，我们可以给一个子类代替
            //Student s = new Student();
            Person p = new Student ();


            //string str=string.Join("|",new string[] { "1", "2", "3" });
            //Console.WriteLine(str);
            //Console.ReadKey();
            //2）如果父类里装的是子类对象，那么可以将这个父类强转为子类对象
            Student ss = (Student)p;//这里的p是装在父类里的子类对象，就是上面的那句Person p = new Student ();
            ss.StudentSayHeello();
            Console.ReadKey();




        }
    }

    public class Person
    {
        public void PersonSayHello()
        {
            Console.WriteLine("我是父类");
        }
    }

    public class Student : Person
    {
        public void StudentSayHeello()
        {
            Console.WriteLine("我是子类");
        }
    }

    public class Teacher : Person
    {
        public void TeacherSayHello()
        {
            Console.WriteLine("我是子类");
        }
    }


}

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

namespace 里氏转换练习
{
    class Program
    {
        static void Main(string[] args)
        {
            //创建10个对象，通过一个循环去调用他们各自打招呼的方法

            Person[] pers = new Person[10];
            Random r = new Random();//新建一个随机数
            for (int i = 0; i < pers.Length; i++)
            {

                int rNumber = r.Next(1, 6);//确定一个变量为随机数，范围从1到5
                switch (rNumber)//1-6
                {
                    case 1:
                        pers[i] = new Student();
                        break;
                    case 2:
                        pers[i] = new Teacher();
                        break;
                    case 3:
                        pers[i] = new Person();
                        break;
                    case 4:
                        pers[i] = new HandsomeBoy();
                        break;
                    case 5:
                        pers[i] = new Beauty();
                        break;
                }

            }

            for (int i = 0; i < pers.Length; i++)
            {
                //pers[i].PersonSayHi();
                if (pers[i] is Student)
                {
                    ((Student)pers[i]).StudentSayHi();
                }
                else if (pers[i] is Teacher)
                {
                    ((Teacher)pers[i]).TeacherSayHi();
                }
                else if (pers[i] is HandsomeBoy)
                {
                    ((HandsomeBoy)pers[i]).HandsomeBoySayHi();
                }
                else if (pers[i] is Beauty)
                {
                    ((Beauty)pers[i]).BeautySayHi();
                }
                else
                {
                    pers[i].PersonSayHi();
                }
            }



            Console.ReadKey();
        }
    }

    public class Person
    {
        public void PersonSayHi()
        {
            Console.WriteLine("我是人类");
        }
    }

    public class Student : Person
    {
        public void StudentSayHi()
        {
            Console.WriteLine("我是学生");
        }
    }
    public class Teacher : Person
    {
        public void TeacherSayHi()
        {
            Console.WriteLine("我是老师");
        }
    }

    public class Beauty : Person
    {
        public void BeautySayHi()
        {
            Console.WriteLine("我是美女");
        }
    }

    public class HandsomeBoy : Person
    {
        public void HandsomeBoySayHi()
        {
            Console.WriteLine("我是帅哥");
        }
    }
}