From c16355e935e641e91be5e5e6b5cbbb8dfc4d0040 Mon Sep 17 00:00:00 2001 From: Kister Hakusan <2753888203@qq.com> Date: Sun, 14 Sep 2025 15:08:38 +0800 Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0Lesson18?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- C#核心/C#核心.sln | 12 ++ .../Lesson18_多态-抽象类和抽象方法.csproj | 11 ++ .../Lesson18_多态-抽象类和抽象方法/Program.cs | 77 ++++++++++++ .../Lesson18_多态-抽象类和抽象方法练习.csproj | 11 ++ .../Program.cs | 111 ++++++++++++++++++ 5 files changed, 222 insertions(+) create mode 100644 C#核心/Lesson18_多态-抽象类和抽象方法/Lesson18_多态-抽象类和抽象方法.csproj create mode 100644 C#核心/Lesson18_多态-抽象类和抽象方法/Program.cs create mode 100644 C#核心/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 create mode 100644 C#核心/Lesson18_多态-抽象类和抽象方法练习/Program.cs diff --git a/C#核心/C#核心.sln b/C#核心/C#核心.sln index f9e4ce1..37b3e4d 100644 --- a/C#核心/C#核心.sln +++ b/C#核心/C#核心.sln @@ -35,6 +35,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson17_多态-vob", "Less EndProject Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson17_多态-vob练习", "Lesson17_多态-vob练习\Lesson17_多态-vob练习.csproj", "{B9598C23-6AD4-44FB-B16B-6A0A80B8D9CD}" EndProject +Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson18_多态-抽象类和抽象方法", "Lesson18_多态-抽象类和抽象方法\Lesson18_多态-抽象类和抽象方法.csproj", "{4EF4F902-1A00-4518-B21C-E7B6264CAB03}" +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 Global GlobalSection(SolutionConfigurationPlatforms) = preSolution Debug|Any CPU = Debug|Any CPU @@ -105,6 +109,14 @@ Global {B9598C23-6AD4-44FB-B16B-6A0A80B8D9CD}.Debug|Any CPU.Build.0 = Debug|Any CPU {B9598C23-6AD4-44FB-B16B-6A0A80B8D9CD}.Release|Any CPU.ActiveCfg = Release|Any CPU {B9598C23-6AD4-44FB-B16B-6A0A80B8D9CD}.Release|Any CPU.Build.0 = Release|Any CPU + {4EF4F902-1A00-4518-B21C-E7B6264CAB03}.Debug|Any CPU.ActiveCfg = Debug|Any CPU + {4EF4F902-1A00-4518-B21C-E7B6264CAB03}.Debug|Any CPU.Build.0 = Debug|Any CPU + {4EF4F902-1A00-4518-B21C-E7B6264CAB03}.Release|Any CPU.ActiveCfg = Release|Any CPU + {4EF4F902-1A00-4518-B21C-E7B6264CAB03}.Release|Any CPU.Build.0 = Release|Any CPU + {7004726B-5B33-4B2A-ADDB-EF22DA593630}.Debug|Any CPU.ActiveCfg = Debug|Any CPU + {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 EndGlobalSection GlobalSection(SolutionProperties) = preSolution HideSolutionNode = FALSE diff --git a/C#核心/Lesson18_多态-抽象类和抽象方法/Lesson18_多态-抽象类和抽象方法.csproj b/C#核心/Lesson18_多态-抽象类和抽象方法/Lesson18_多态-抽象类和抽象方法.csproj new file mode 100644 index 0000000..b9b92b9 --- /dev/null +++ b/C#核心/Lesson18_多态-抽象类和抽象方法/Lesson18_多态-抽象类和抽象方法.csproj @@ -0,0 +1,11 @@ + + + + Exe + net8.0 + Lesson18_多态_抽象类和抽象方法 + enable + enable + + + diff --git a/C#核心/Lesson18_多态-抽象类和抽象方法/Program.cs b/C#核心/Lesson18_多态-抽象类和抽象方法/Program.cs new file mode 100644 index 0000000..492cc34 --- /dev/null +++ b/C#核心/Lesson18_多态-抽象类和抽象方法/Program.cs @@ -0,0 +1,77 @@ +namespace Lesson18_多态_抽象类和抽象方法 +{ + #region 知识点一 抽象类 + //概念 + //被抽象关键字abstract修饰的类 + //特点： + //1.不能被实例化的类 + //2.可以包含抽象方法 + //3.继承抽象类必须重写其抽象方法 + + abstract class Thing + { + //抽象类中封装的知识点都可以用 + public string name; + //可以在抽象类中写抽象函数 + } + class Water : Thing + { + + } + + #endregion + + #region 知识点二 抽象函数 + //又叫 纯 虚方法 + //用abstract关键字修饰的方法 + //特点： + //1.只能在抽象类中声明 + //2.没有方法体 + //3.不能是私有的 + //4.继承后必须实现 用override重写 + abstract class Fruit + { + public string name; + public abstract void Bad();//抽象方法 是一定不能有函数体的（大括号什么的）并且在子类中必须重写 + public virtual void Test()//虚方法可以不重写 + { + + } + } + class Apple : Fruit + { + public override void Bad() + { + Console.WriteLine(); + } + } + class SuperApple : Apple + { + public override void Bad() + { + base.Bad(); + } + public override void Test() + { + base.Test(); + } + } + #endregion + internal class Program + { + static void Main(string[] args) + { + //抽象类不能被实例化 + //Thing t = new Thing(); + + //遵循里氏替换原则 + Thing water = new Water(); + } + } + //总结： + //如何选择普通类和抽象类？ + //不希望被实例化的对象，比较笼统的对象 + //例如：水果，人，事情 + //或 父类中的行为不太需要被实现的，只希望子类区定义具体的规则的 + //可以选择抽象类 +} diff --git a/C#核心/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 b/C#核心/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 new file mode 100644 index 0000000..4ce73f5 --- /dev/null +++ b/C#核心/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 @@ -0,0 +1,11 @@ + + + + Exe + net8.0 + Lesson18_多态_抽象类和抽象方法练习 + enable + enable + + + diff --git a/C#核心/Lesson18_多态-抽象类和抽象方法练习/Program.cs b/C#核心/Lesson18_多态-抽象类和抽象方法练习/Program.cs new file mode 100644 index 0000000..479ba74 --- /dev/null +++ b/C#核心/Lesson18_多态-抽象类和抽象方法练习/Program.cs @@ -0,0 +1,111 @@ +using System.Drawing; + +namespace Lesson18_多态_抽象类和抽象方法练习 +{ + abstract class Animal + { + public abstract void Shout(); + } + class Human : Animal + { + public override void Shout() + { + Console.WriteLine("人叫"); + } + } + class Dog : Animal + { + public override void Shout() + { + Console.WriteLine("狗叫"); + } + } + class Cat : Animal + { + public override void Shout() + { + Console.WriteLine("猫叫"); + } + } + abstract class Graph + { + public abstract void Perimeter(); + public abstract void Area(); + } + class RectAngle : Graph + { + private int x, y; + public RectAngle(int x,int y) + { + this.x = x; + this.y = y; + } + public override void Area() + { + Console.WriteLine("面积为:"+x*y); + } + + public override void Perimeter() + { + Console.WriteLine("周长为"+(x+y)*2); + } + } + class Square : Graph + { + private int x; + public Square(int x) + { + this.x = x; + } + public override void Area() + { + Console.WriteLine("面积为:" + x * x); + } + + public override void Perimeter() + { + Console.WriteLine("周长为" + x * 4); + } + } + class Round : Graph + { + private double PI = 3.1415926; + int r; + public Round(int r) + { + this.r = r; + } + public override void Perimeter() + { + double perimeter = 2 * PI * r; + Console.WriteLine("圆的周长{0}", perimeter); + } + public override void Area() + { + double areas = PI * r * r; + Console.WriteLine("圆的面积{0}", areas); + } + } + internal class Program + { + static void Main(string[] args) + { + Animal human = new Human(); + human.Shout(); + Animal dog = new Dog(); + dog.Shout(); + Animal cat = new Cat(); + cat.Shout(); + + Graph rectangle = new RectAngle(2, 3); + rectangle.Perimeter(); + rectangle.Area(); + Graph square = new Square(2); + square.Perimeter(); + square.Area(); + Graph round = new Round(3); + round.Perimeter(); + round.Area(); + } + } +}