C#视频 - Interface 接口

 

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

namespace ConsoleApplication1
{
    interface IDrivingLicenseB
    {
        void GetLicense();
    }

    interface IDrivingLicenseA : IDrivingLicenseB
    {
        new void GetLicense();
    }

    class Teacher : IDrivingLicenseA
    {
        public void GetLicense()
        {
            Console.WriteLine("Teacher got license A.");
        }
    }

    class Student : IDrivingLicenseB
    {
        public void GetLicense()
        {
            Console.WriteLine("Student got license B.");
        }
    }

    class Program
    {
        static void DriveCar(string name, IDrivingLicenseB o)
        {
            IDrivingLicenseB dl = o as IDrivingLicenseB;
            if (dl != null)
            {
                Console.WriteLine("drive car.");
            }
            else
            {
                Console.WriteLine("cannot drive car.");
            }
        }

        static void DriveBus(string name, IDrivingLicenseB o)
        {
            IDrivingLicenseA dl = o as IDrivingLicenseA;
            if (dl != null)
            {
                Console.WriteLine("drive bus.");
            }
            else
            {
                Console.WriteLine("cannot drive bus.");
            }
        }

        static void Main(string[] args)
        {
            Teacher t = new Teacher();
            DriveCar("Teacher", t);
            DriveBus("Teacher", t);

            Student s = new Student();
            DriveCar("Student", s);
            DriveBus("Student", s);

            Console.ReadKey();
        }
    }
}

 

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

namespace ConsoleApplication1
{
    interface IDrivingLicenseB
    {
        void GetLicense();
    }

    interface IDrivingLicenseA : IDrivingLicenseB
    {
        new void GetLicense();
    }

    class Teacher : IDrivingLicenseA
    {
        void IDrivingLicenseA.GetLicense()
        {
            Console.WriteLine("Teacher got license A.");
        }

        void IDrivingLicenseB.GetLicense()
        {
            Console.WriteLine("Teacher got license B.");
        }

        public void GetLicense()
        {
            Console.WriteLine("VVVB.");
        }
    }

    class Student : IDrivingLicenseB
    {
        public void GetLicense()
        {
            Console.WriteLine("Student got license B.");
        }
    }

    class Program
    {
        static void DriveCar(string name, IDrivingLicenseB o)
        {
            IDrivingLicenseB dl = o as IDrivingLicenseB;
            if (dl != null)
            {
                Console.WriteLine("drive car.");
            }
            else
            {
                Console.WriteLine("cannot drive car.");
            }
        }

        static void DriveBus(string name, IDrivingLicenseB o)
        {
            IDrivingLicenseA dl = o as IDrivingLicenseA;
            if (dl != null)
            {
                Console.WriteLine("drive bus.");
            }
            else
            {
                Console.WriteLine("cannot drive bus.");
            }
        }

        static void Main(string[] args)
        {
            Teacher t = new Teacher();
            ((IDrivingLicenseA)t).GetLicense();
            ((IDrivingLicenseB)t).GetLicense();
            t.GetLicense();

            //DriveCar("Teacher", t);
            //DriveBus("Teacher", t);

            //Student s = new Student();
            //DriveCar("Student", s);
            //DriveBus("Student", s);

            Console.ReadKey();
        }
    }
}

完全限定名不能用public修饰符修饰。去掉public，即为private。

 

 接口的多继承：

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

namespace ConsoleApplication1
{
    interface IA
    {
        void F();
    }

    interface IB : IA
    {
        new void F();
    }

    interface IC : IA
    {
        void G();
    }

    interface IBC : IB, IC
    {

    }

    class D: IBC
    {
        public void F()
        {
            Console.WriteLine("IB.F()");
        }

        public void G()
        {
            Console.WriteLine("IC.G()");
        }
    }
    
    class Program
    {
       
        static void Main(string[] args)
        {
            D d = new D();
            ((IBC)d).F();
            ((IB)d).F();
            ((IC)d).F();
            ((IA)d).F();

            Console.ReadKey();
        }
    }
}

Note：
调用IC的F方法，IC的F方法继承自IA接口。接口多重继承原则：直观隐藏规则。如果成员在任何一个路径中被隐藏，则他在任何一个路径中也被隐藏掉。

 

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

namespace ConsoleApplication1
{
    interface IA
    {
        void F();
    }

    class B: IA
    {
        void IA.F()
        {
            Console.WriteLine("B.F");
        }
    }

    class C : B, IA
    {
        public void F()
        {
            Console.WriteLine("C.F");
        }
    }
    
    class Program
    {
       
        static void Main(string[] args)
        {
            C c = new C();

            ((IA)c).F();
            //((B)c).F();
            
            Console.ReadKey();
        }
    }
}

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

namespace ConsoleApplication1
{
    interface IA
    {
        void F();
    }

    class B: IA
    {
        void IA.F()
        {
            Console.WriteLine("B.F");
        }
    }

    class C : B, IA
    {
        public void F()
        {
            Console.WriteLine("C.F");
        }
    }
    
    class Program
    {
       
        static void Main(string[] args)
        {
            C c = new C();

            ((IA)c).F();

            B b = c;
            ((IA)b).F();
            
            Console.ReadKey();
        }
    }
}