第二十四节 interface接口

案例1：new 关键字运用

namespace e1
{
    class A
    {
        public void F()
        {
        }
    }

    class B:A
    {
        public new void F()
        { 
            //在继承结构中,子类要隐藏父类的方法,可以不加new关键字
            //但这样编译器会报一个警告,虽然这样可以达到方法隐藏的目的
            //但是我们不推荐这样做,好的编写习惯是使用严谨的语法尽可能的避免错误的发生
        }

        //public void F()
        //{     
        //}
    }
    class Program
    {
        static void Main(string[] args)
        {
        }
    }

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案例2：接口

namespace e2
{
    //访问修饰符 interface 接口名
    //{
            //  内容:(接口内所有内容都是抽象的,无具体实现)
    //}
    
    public interface IHomeworkCollector
    {
        //接口里所有的内容都是公开的,所以不必定义访问修饰符
        void HomeworkCollector();
    }

    public class Person
    {
        protected string name;
       
        public Person(string name)
        {
            this.name = name;
        }
    }

    public class Student:Person,IHomeworkCollector
    {
        public Student(string name) : base(name) { }
        public void HomeworkCollector()
        {
            Console.WriteLine("{0}开始收作业",name);
        }
    }
    public class Teacher : Person, IHomeworkCollector
    {
         public Teacher (string name) : base(name) { }
        public void HomeworkCollector()
        {
            Console.WriteLine("你怎么还在抄作业啊啊啊啊!!!,{0}老师开始收作业", name);
        }
    }

    public class Adviser : Person, IHomeworkCollector
    {
        public Adviser(string name) : base(name) { }
        public void HomeworkCollector()
        {
            Console.WriteLine("{0},班主任来收作业了", name);
        }
    }

    class Program
    {
         //接口当做参数来用
        public void ExecutHomeworkCollector(IHomeworkCollector ic)
        {
            ic.HomeworkCollector();
        }
       //接口当做返回值使用
        public  IHomeworkCollector CreateHomeworkCollector(string type)
        {
            switch (type.Trim())
            {
                case "student": return  new  Student("王五");
                case "teacher": return new Teacher("依依"); 
                case "adviser": return new Adviser("散散");
                default: return null;
                    
            }            
            
        }
        
        static void Main(string[] args)
        {
            //知识点
            //接口不能实例化
            //IHomeworkCollector ic = new IHomeworkCollector();

            //方法4
            Program p = new Program();
            IHomeworkCollector ic = p.CreateHomeworkCollector("student");
            ic.HomeworkCollector();
            ic = p.CreateHomeworkCollector("adviser");
            ic.HomeworkCollector();
            
            //方法3
            //Program p = new Program();
            //p.ExecutHomeworkCollector(new Student("田科"));
            //p.ExecutHomeworkCollector(new Teacher("王启"));
            //p.ExecutHomeworkCollector(new Adviser("我靠!!!"));

            //方法1:
            //IHomeworkCollector ic = new Student("张三");
            //ic.HomeworkCollector();
            //IHomeworkCollector ic = new Teacher("李四");
            //ic.HomeworkCollector();
           
             
            //方法2
            ////List<IHomeworkCollector> list = new List<IHomeworkCollector>();

            ////list.Add(new Student("张三"));
            ////list.Add(new Teacher("李"));
            ////foreach (IHomeworkCollector ic in list)
            ////{
            ////    ic.HomeworkCollector();
            ////}
            
            Console.ReadKey();
        }
    }
}

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案例3存取款

namespace e3
{
    interface IBankAccount
    {
        //在接口中定义一组规范(契约)
        //要求所有银行的账户系统按照该接口的规范来开发

        //取款
        void PayIn(decimal amount);
        //存款
        bool WithDrow(decimal amount);
        

        //余额
        decimal Balance
        {
            get;
        }        
    }
}

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namespace e3
{
    class ICBAccount:ITransferBankAcount

    {
        private decimal balance;
        public void PayIn(decimal amount) 
        {
            balance += amount;
        }

        public bool WithDrow(decimal amount)
        {
            if (balance >= amount)
            {
                balance -= amount;
                return true;
            }
            else
            {
                Console.WriteLine("余额不足..........");
                return false;
            }
        }
        //转账
        public void TransferAcount(IBankAccount account, decimal amount) 
        {
            bool flag= this.WithDrow(amount);
            if (flag)
            {
                account.PayIn(amount);
            }
        }

        public decimal Balance
        {
            set { balance = value; }
            get { return balance; }
        }
    }
}
————————————————————————————————

namespace e3
{
    interface ITransferBankAcount:IBankAccount
    {
        //转账
        void TransferAcount(IBankAccount account, decimal amount);
    }
}
————————————————————————

namespace e3
{
    
    class Program
    {
        static void Main(string[] args)
        {
            ITransferBankAcount ia = new ICBAccount();
            ia.PayIn(2000);
            ia.WithDrow(500);
            Console.WriteLine("余额:{0}", ia.Balance);

            IBankAccount ia2 = new ICBAccount();
            ia.TransferAcount(ia2, 500);
            Console.WriteLine("ia的余额:{0}",ia.Balance);
            Console.WriteLine("ia2的余额:{0}", ia2.Balance);
            Console.ReadKey();
        }
    }
}

案例1：习题

namespace l1
{
    class Mammal
    {
        public virtual void SayHi()
        {
            Console.WriteLine("我是怪兽！！！");
        }
    }

    class Anmainal : Mammal
    {
        public override void SayHi()
        {
            Console.WriteLine("我是一只野兽！！！");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Anmainal an = new Anmainal();
            an.SayHi();
            Console.ReadKey();
        }
    }
}

——————————————————————————————————

namespace l1
{
    class Mammal
    {
        public override string ToString()
        {
            return "我是一只野兽";
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Mammal mammal = new Mammal();
            Console.WriteLine(mammal);
            Console.WriteLine(mammal.ToString());
            Console.ReadKey();
        }
    }
}

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案例2：

namespace l2
{
    abstract class Vertebrata
    {
        public abstract void ShowMyself();
    }
}

——————————————————————

namespace l2
{
    class Amphibian:Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Frog:Amphibian
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n  @..@" 
               +"\n ()"
              +"\n(.>__<.)"
              +"\n^^^  ^^^");
        }
    }


}

——————————————————————————

namespace l2
{
    class Bird : Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine("  _，"
                             + "\n-==<' `\\"
                             + "\n    ) /"
                             + "\n    /(_."
                             + "\n  | ,-,`\\"
                             + "\n   \\\\  \\ \\"
                             + "\n    \\, \\ \\"
                             + "\n     ||\\ \\`|,"
                             + "\n    _|| `=`-'"
                             + "\n  ~~`~`");
        }
    }
    class Duck : Bird
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n  >(' )"
                                  +"\n   )/"
                                  +"\n  /( "
                                  +" \n/  `----/ "
                                  +"\n\\ ~=- /");
        }
    }

}

——————————————————————————————————

namespace l2
{
    class Mammal:Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Rabbit:Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Human : Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine("╭∩╮（︶︿︶）╭∩╮鄙视你!");
        }
    }

    class Cattle : Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n(___)"
                             +"\n(o o)_____/"
                             +"\n  @@ `     \\  "       
                             +"\n \\____, /"
                             +"\n //    // "
                             + "\n^^    ^^ ");
        }
    }
    class Pig:Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

}

——————————————————————————


namespace l2
{ 
  
    class Program
    {
        static void Main(string[] args)
        {
            Bird bd = new Bird();
            bd.ShowMyself();
            Cattle cl=new Cattle();
            cl.ShowMyself();
            Frog fg = new Frog();
            fg.ShowMyself();
            Duck dk = new Duck();
            dk.ShowMyself();
            
            Console.ReadKey();
        }
    }
}

 

案例1：习题

namespace l3
{
    abstract class Vertebrata
    {
        public abstract void ShowMyself();
    }
}
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namespace l3
{
    class Mammal:Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Rabbit:Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Human : Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine("╭∩╮（︶︿︶）╭∩╮鄙视你!");
        }
    }

    class Cattle : Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n(___)"
                             +"\n(o o)_____/"
                             +"\n  @@ `     \\  "       
                             +"\n \\____, /"
                             +"\n //    // "
                             + "\n^^    ^^ ");
        }
    }
    class Pig:Mammal
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

}

——————————————————————————

namespace l3
{
    class Bird : Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine("  _，"
                             + "\n-==<' `\\"
                             + "\n    ) /"
                             + "\n    /(_."
                             + "\n  | ,-,`\\"
                             + "\n   \\\\  \\ \\"
                             + "\n    \\, \\ \\"
                             + "\n     ||\\ \\`|,"
                             + "\n    _|| `=`-'"
                             + "\n  ~~`~`");
        }
    }
    class Duck : Bird
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n  >(' )"
                                  +"\n   )/"
                                  +"\n  /( "
                                  +" \n/  `----/ "
                                  +"\n\\ ~=- /");
        }
    }

}

——————————————————————————

namespace l3
{
    class Amphibian:Vertebrata
    {
        public override void ShowMyself()
        {
            Console.WriteLine();
        }
    }

    class Frog:Amphibian
    {
        public override void ShowMyself()
        {
            Console.WriteLine("\n  @..@" 
               +"\n ()"
              +"\n(.>__<.)"
              +"\n^^^  ^^^");
        }
    }
}
——————————————————————————————

namespace l3
{
    class Program
    {
        static void Main(string[] args)
        {
            Human jean = new Human();
            Vertebrata someone = jean;
            if(someone is Human)
                Console.WriteLine("someone is Human");
            if(someone is Mammal)
                Console.WriteLine("someone is Mammal");
            if(someone is Vertebrata)
                Console.WriteLine("someone is Vertebrata");
            Console.ReadKey();
        }
    }
}
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案例2：

namespace l4
{
    class Vertebrata
    { 
    }

    class Human:Vertebrata
    {
        public void Work()
        {
            Console.WriteLine("说话");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            //人属于人类,人也属于脊椎动物，但脊椎动物不能有人说话的能力
            //Human jean = new Human();
            //Vertebrata someone = jean;
            //someone.Work();

            Human jean = new Human();
            Vertebrata someone = jean;
            Human people = someone as Human;
            if (people != null)
            {
                people.Work();
            }
            Console.ReadKey();
        }
    }
}

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案例3

namespace l5
{
    interface IDriveable
    {
        void Drive();
    }
    class BusDriver:IDriveable 
    {
        public void Drive()
        {
            Console.WriteLine("有经验的司机可以驾驶公共汽车");
        }
    }
    class TractorDriver:IDriveable
    {
        public void Drive()
        {
            Console.WriteLine("拖拉机的司机可以去玩");
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            IDriveable id = new BusDriver();
            id.Drive();
            IDriveable ic = new TractorDriver();
            ic.Drive(); 
            Console.ReadKey();
        }
    }
}