一、如何用接口实现多态？

1.定义一个接口。

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace 继承之抽象类{    public interface people  //定义一个接口People    {               void SayHi();   //定义一个SayHi方法    }}

2.创建两个类Student.c和Teacher.cs继承接口

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace 继承之抽象类{    class Student:people  //继承接口Peoper    {        public void SayHi()        {            Console.WriteLine("你好我是学生");        }    }}

using System;    using System.Collections.Generic;    using System.Linq;    using System.Text;    namespace 继承之抽象类    {        class Teacher:people  //继承接口Peoper        {            public void SayHi()            {                Console.WriteLine("你好我是老师");            }        }    }

3.创建一个program.cs类用来输出结果　　

using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace 继承之抽象类{    class Program    {       static List
     
       peopers = new List
      
       ();  //定义一个泛型实例        public static void InitData()        {            Student st = new Student();            Teacher tc = new Teacher();            peopers.Add(st);            peopers.Add(tc);        }        public static void Start()        {            foreach (people peoper in peopers)  //遍历泛型实例            {                peoper.SayHi();            }        }        static void Main(string[] args)        {            InitData();            Start();            Console.ReadLine();        }    }}
      
     

输出结果：