using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Text;

 using System.Threading.Tasks;

 namespace 接口

 {

     /// <summary>

     /// 接口：定义一个统一的标准

     /// 声明接口，接口中，只包含成员的生命，不包含任何的代码实现。

     /// 接口成员总是公有的，不添加也不需要添加public，也不能声明虚方法和虚静态方法

     /// </summary>

     interface IBankAccount

     {

         //方法

         void PayIn(decimal amount);

         //方法

         bool WithShowMyself(decimal amount);

         //属性

         decimal Balance { get; }

     }

     /// <summary>

     /// 继承自IBankAccount的接口

     /// </summary>

     interface ITransferBankAccount : IBankAccount

     {

         //转账          ：转入的目的地             ：转入金额

         bool TransferTo(IBankAccount destination, decimal amount);

     }

     class SaveAcount : IBankAccount

     {

         //私有变量

         private decimal banlance;

         //存款

         public void PayIn(decimal amount)

         {

             banlance += amount;

         }

         //取款

         public bool WithShowMyself(decimal amount)

         {

             if (banlance >= amount)

             {

                 banlance -= amount;

                 return true;

             }

             else

             {

                 Console.WriteLine("余额不足！");

                 return false;

             }

         }

         //账户余额

         public decimal Balance

         {

             get

             {

                 return banlance;

             }

         }

     }

     //实现接口的类的相应成员必须添加public修饰

     class ITransferAccount : ITransferBankAccount

     {

         //私有变量

         private decimal banlance;

         //存款

         public void PayIn(decimal amount)

         {

             banlance += amount;

         }

         //取款

         public bool WithShowMyself(decimal amount)

         {

             if (banlance >= amount)

             {

                 banlance -= amount;

                 return true;

             }

             else

             {

                 Console.WriteLine("余额不足！");

                 return false;

             }

         }

         //账户余额

         public decimal Balance

         {

             get

             {

                 return banlance;

             }

         }

         //转账

         public bool TransferTo(IBankAccount destination, decimal amount)

         {

             bool result = WithShowMyself(amount);

             if (result == true)

             {

                 destination.PayIn(amount);

             }

             return result;

         }

     }

     class Program

     {

         static void Main(string[] args)

         {

             IBankAccount MyAccount = new SaveAcount();

             ITransferAccount YourAccount = new ITransferAccount();

             MyAccount.PayIn();

             YourAccount.PayIn();

             YourAccount.TransferTo(MyAccount, );

             Console.WriteLine(MyAccount.Balance);//

             Console.WriteLine();

             Console.WriteLine(YourAccount.Balance);//

             Console.ReadKey();

         }

     }

 }