abstract

 /// <summary>
     /// 抽象类不能被直接实例化
     /// is a
     /// </summary>
     public abstract class BasePhone
     {
         public void Show()
         {
             Console.WriteLine("");
         }

         public int Price { get; set; }

         /// <summary>
         /// 品牌
         /// </summary>
         /// <returns></returns>
         public abstract string Brand();

         /// <summary>
         /// 系统
         /// </summary>
         /// <returns></returns>
         public abstract string System();

         /// <summary>
         /// 打电话
         /// </summary>
         public abstract void Call();

         /// <summary>
         /// 拍照
         /// </summary>
         public abstract void Photo();

2.基本接口作为约束

     /// <summary>
     /// can do
     /// </summary>
     public interface IExtend
     {
         void ApplePay();
     }

     public interface INet
     {
         void Online();
     }

接口

3.各个手机的实现

     /// <summary>
     /// 手机
     /// </summary>
     public class iPhone : BasePhone, IExtend, INet
     {
         /// <summary>
         /// 品牌
         /// </summary>
         /// <returns></returns>
         public override string Brand()
         {
             return "iPhone";
         }

         /// <summary>
         /// 系统
         /// </summary>
         /// <returns></returns>
         public override string System()
         {
             return "IOS";
         }

         /// <summary>
         /// 打电话
         /// </summary>
         public override void Call()
         {
             Console.WriteLine("User{0} {1} {2} Call", this.GetType().Name, this.Brand(), this.System());
         }

         /// <summary>
         /// 拍照
         /// </summary>
         public override void Photo()
         {
             Console.WriteLine("User{0} {1} {2} Call", this.GetType().Name, this.Brand(), this.System());
         }

         public void ApplePay()
         {
             Console.WriteLine("User{0} {1} {2} ApplePay", this.GetType().Name, this.Brand(), this.System());
         }

         public void Online()
         {
             Console.WriteLine("User{0} {1} {2} Online", this.GetType().Name, this.Brand(), this.System());
         }
     }

iPhone

     /// <summary>
     /// 手机
     /// </summary>
     public class Lumia : BasePhone
     {
         /// <summary>
         /// 品牌
         /// </summary>
         /// <returns></returns>
         public override string Brand()
         {
             return "Nokia";
         }

         /// <summary>
         /// 系统
         /// </summary>
         /// <returns></returns>
         public override string System()
         {
             return "Winphone";
         }

         /// <summary>
         /// 打电话
         /// </summary>
         public override void Call()
         {
             Console.WriteLine("User{0} {1} {2} Call", this.GetType().Name, this.Brand(), this.System());
         }

         /// <summary>
         /// 拍照
         /// </summary>
         public override void Photo()
         {
             Console.WriteLine("User{0} {1} {2} Call", this.GetType().Name, this.Brand(), this.System());
         }
     }

Lumia

     public class Mi : BasePhone
     {
         /// <summary>
         /// 品牌
         /// </summary>
         /// <returns></returns>
         public override string Brand()
         {
             return "XiaoMi";
         }

         /// <summary>
         /// 系统
         /// </summary>
         /// <returns></returns>
         public override string System()
         {
             return "Android";
         }

         /// <summary>
         /// 打电话
         /// </summary>
         public override void Call()
         {
             Console.WriteLine("User{0} {1} {2} Call", this.GetType().Name, this.Brand(), this.System());
         }

         /// <summary>
         /// 拍照
         /// </summary>
         public override void Photo()
         {
             Console.WriteLine("User{0} {1} {2} Photo", this.GetType().Name, this.Brand(), this.System());
         }
     }

Mi

abstract用override写,接口直接实现.