添加Lesson19

C#核心/C#核心.sln

@@ -39,6 +39,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson18_多态-抽象类
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson18_多态-抽象类和抽象方法练习", "Lesson18_多态-抽象类和抽象方法练习\Lesson18_多态-抽象类和抽象方法练习.csproj", "{7004726B-5B33-4B2A-ADDB-EF22DA593630}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson19_多态-接口", "Lesson19_多态-接口\Lesson19_多态-接口.csproj", "{FC39DDE9-AC80-40A2-9CCA-DC06510A8881}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson19_多态-接口练习", "Lesson19_多态-接口练习\Lesson19_多态-接口练习.csproj", "{D511EDF3-7769-45BB-8304-3081918FA633}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -117,6 +121,14 @@ Global
 		{7004726B-5B33-4B2A-ADDB-EF22DA593630}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{7004726B-5B33-4B2A-ADDB-EF22DA593630}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{7004726B-5B33-4B2A-ADDB-EF22DA593630}.Release|Any CPU.Build.0 = Release|Any CPU
+		{FC39DDE9-AC80-40A2-9CCA-DC06510A8881}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{FC39DDE9-AC80-40A2-9CCA-DC06510A8881}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{FC39DDE9-AC80-40A2-9CCA-DC06510A8881}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{FC39DDE9-AC80-40A2-9CCA-DC06510A8881}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D511EDF3-7769-45BB-8304-3081918FA633}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D511EDF3-7769-45BB-8304-3081918FA633}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D511EDF3-7769-45BB-8304-3081918FA633}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D511EDF3-7769-45BB-8304-3081918FA633}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

C#核心/Lesson19_多态-接口/Lesson19_多态-接口.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <RootNamespace>Lesson19_多态_接口</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

C#核心/Lesson19_多态-接口/Program.cs

@@ -0,0 +1,189 @@
+namespace Lesson19_多态_接口
+{
+    #region 知识点一 接口的概念
+    //接口是行为的抽象规范
+    //他也是一种自定义类型
+    //关键字 interface
+
+    //接口声明的规范
+    //1.不包含成员变量
+    //2.只包含方法、属性、索引器、事件
+    //3.成员不能被实现
+    //4.成员可以不用写访问修饰符，不能是私有的
+    //5.接口不能继承类，但是可以继承另一个接口
+
+    //接口的使用规范
+    //1.类可以继承多个接口
+    //2.类继承接口后，必须实现接口中所有成员
+
+    //特点：
+    //1.他和类的声明类似
+    //2.接口是用来继承的
+    //3.接口不能被实例化，但是可以作为容器存储对象
+    #endregion
+
+    #region 知识点二 接口的声明
+    //接口的关键字：interface
+    //语法：
+    //interface 接口名
+    //{
+    //}
+    //一句话记忆：接口是抽象行为的基类
+    //接口命名规范 帕斯卡前面加个I
+    interface IFly
+    {
+        //int a;不能包含成员变量
+        void Fly();//可以加public和protect，不能加private这样违反了上面使用规范知识点的2
+        string Name 
+        { 
+            get; 
+            set; 
+        }
+        int this[int index]
+        {
+            get;
+            set;
+        }
+
+        event Action doSomthing;//先不学事件声明
+    }
+    #endregion
+
+    #region 知识点三 接口的使用
+    class Animal
+    {
+
+    }
+    //接口用来继承
+    //1.类可以继承1个类，n个接口
+    //2.继承了接口后 必须实现其中的内容 并且必须是public的
+    class Human : Animal, IFly
+    {
+        public int this[int index] 
+        {
+            get
+            {
+                return 0;
+            }
+            set
+            {
+                this[index] = value;
+            } 
+        }
+        public string Name 
+        { 
+            get; 
+            set; 
+        }
+        public event Action doSomthing;
+        //3.实现的接口函数，可以通过加virtual再在子类中重写
+        //4.接口也遵循里氏替换原则
+        public virtual void Fly()
+        {
+            Console.WriteLine("人飞");
+        }
+    }
+    #endregion
+
+    #region 知识点四 接口可以继承接口
+    //接口继承接口时 不需要实现
+    //待类继承接口后 类自己去实现所有内容
+    interface IWalk
+    {
+        void Walk();
+    }
+    interface IMove : IFly,IWalk
+    {
+        void Move();
+    }
+    class Test : IMove
+    {
+        public int this[int index] { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
+
+        public string Name { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
+
+        public event Action doSomthing;
+
+        public void Fly()
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Move()
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Walk()
+        {
+            throw new NotImplementedException();
+        }
+    }
+    #endregion
+
+    #region 知识点五 显示实现接口
+    //当一个类继承两个接口
+    //但是接口中存在着同名方法时
+    //注意：显示实现接口时 不能写访问修饰符
+
+    interface IAtk
+    {
+        void Atk();
+    }
+    interface ISuperAtk
+    {
+        void Atk();
+    }
+    class Player : ISuperAtk, IAtk
+    {
+        void ISuperAtk.Atk()//显示实现接口就是 接口名.方法
+        {
+            throw new NotImplementedException();
+        }
+
+        void IAtk.Atk()
+        {
+            throw new NotImplementedException();
+        }
+        public void Atk()
+        {
+            throw new NotImplementedException();
+        }
+    }
+    #endregion
+    internal class Program
+    {
+        static void Main(string[] args)
+        {
+            //IFly f = new IFly();不能被实例化
+            IFly f = new Human();//可以用里氏替换原则
+            f.Fly();
+
+            IMove m = new Test();
+            IFly f2 = new Test();
+            IWalk w = new Test();
+
+
+            IAtk ia = new Player();
+            ISuperAtk isa = new Player();
+
+            Player p = new Player();
+            (p as IAtk).Atk();
+            (p as ISuperAtk).Atk();
+            p.Atk();
+        }
+    }
+
+    // 总结:
+    // 继承类：是对象间的继承，包括特征行为等等
+    // 继承接口：是行为间的继承，继承接口的行为规范，按照规范去实现内容
+    // 由于接口也是遵循里氏替换原则，所以可以用接口容器装对象
+    // 那么久可以实现 装载各种毫无关系但是却有相同行为的对象
+
+    // 注意:
+    //1. 接口值包含 成员方法、属性、索引器、事件，并且都不实现，都没有访问修饰符
+    //2. 可以继承多个接口，但是只能继承一个类
+    //3. 接口可以继承接口，相当于在进行行为合并，待子类继承时再去实现具体的行为
+    //4. 接口可以被显示实现 主要用于实现不同接口中的同名函数的不同表现
+    //5. 实现的接口方法 可以加 virtual 关键字 之后子类 再重写
+}

C#核心/Lesson19_多态-接口练习/Lesson19_多态-接口练习.csproj

@@ -0,0 +1,11 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <RootNamespace>Lesson19_多态_接口练习</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

C#核心/Lesson19_多态-接口练习/Program.cs

@@ -0,0 +1,185 @@
+using Lesson19_多态_接口练习;
+
+namespace Lesson19_多态_接口练习
+{
+    interface ICheck
+    {
+        public void Check();
+    }
+    class Person : ICheck
+    {
+        public void Check()
+        {
+            Console.WriteLine("派出所登记");
+        }
+    }
+    class Car
+    {
+        public void Check()
+        {
+            Console.WriteLine("车管所登记");
+        }
+    }
+    class House
+    {
+        public void Check()
+        {
+            Console.WriteLine("房管局登记");
+        }
+    }
+
+
+    interface IFly
+    {
+        public void Fly();
+    }
+    interface IWalk
+    {
+        public void Walk();
+    }
+    interface ISwim
+    {
+        public void Swim();
+    }
+
+    class Sparrow : IFly, IWalk
+    {
+        public void Fly()
+        {
+            Console.WriteLine("麻雀飞");
+        }
+        public void Walk()
+        {
+            Console.WriteLine("麻雀走");
+        }
+    }
+    class Ostrich : IWalk
+    {
+        public void Walk()
+        {
+            Console.WriteLine("鸵鸟走");
+        }
+    }
+    class Penguin : IWalk, ISwim
+    {
+        public void Walk()
+        {
+            Console.WriteLine("企鹅走");
+        }
+        public void Swim()
+        {
+            Console.WriteLine("企鹅游泳");
+        }
+    }
+    class Parrot : IFly, IWalk
+{
+        public void Fly()
+        {
+            Console.WriteLine("鹦鹉飞");
+        }
+        public void Walk()
+        {
+            Console.WriteLine("走");
+        }
+    }
+    class Helicopter : IFly
+    {
+        public void Fly()
+        {
+            Console.WriteLine("直升机飞");
+        }
+    }
+    class Swan : IFly, IWalk, ISwim
+    {
+        public void Fly()
+        {
+            Console.WriteLine("天鹅飞");
+        }
+        public void Walk()
+        {
+            Console.WriteLine("天鹅走");
+        }
+        public void Swim()
+        {
+            Console.WriteLine("天鹅游泳");
+        }
+    }
+
+
+    interface IUSB
+    {
+        void ReadData();
+    }
+
+    class StorageDevice : IUSB
+    {
+        public string name;
+        public StorageDevice(string name)
+        {
+            this.name = name;
+        }
+        public void ReadData()
+        {
+            Console.WriteLine("USB{0}传输数据",name);
+        }
+    }
+
+    class MP3 : IUSB
+    {
+        public void ReadData()
+        {
+            Console.WriteLine("MP3传输数据");
+        }
+    }
+    class Computer
+    {
+        public IUSB usb1;
+    }
+    internal class Program
+    {
+        static void Main(string[] args)
+        {
+            Console.WriteLine("Hello, World!");
+            Person p1= new Person();
+            p1.Check();
+            Car c1 = new Car();
+            c1.Check();
+            House h1  = new House();
+            h1.Check();
+
+            Sparrow s1 = new Sparrow();
+            s1.Walk();
+            s1.Fly();
+            Ostrich o1 = new Ostrich();
+            o1.Walk();
+            Penguin p2 = new Penguin();
+            p2.Swim();
+            p2.Walk();
+            Parrot p3 = new Parrot();
+            p3.Walk();
+            p3.Fly();
+            Helicopter h2 = new Helicopter();
+            h2.Fly();
+            Swan s3  = new Swan();
+            s3.Walk();
+            s3.Fly();
+            s3.Swim();
+
+            StorageDevice hd = new StorageDevice("移动硬盘");
+            StorageDevice ud = new StorageDevice("U盘");
+            MP3 mp3 = new MP3();
+            Computer computer = new Computer();
+
+            computer.usb1 = hd;
+            computer.usb1.ReadData();
+
+            computer.usb1 = ud;
+            computer.usb1.ReadData();
+
+            computer.usb1 = mp3;
+            computer.usb1.ReadData();
+
+
+        }
+    }
+}