c# 第八章多态与案例

51 接口interface

csharp 复制代码

using System.Diagnostics;

interface IFlyable
{
    void Fly();
    int MaxALtitude { get; set; }
}

class Bird :IFlyable
{
    private int maxAltitude;

    public void Fly()
    {
        Console.WriteLine("鸟在飞");
    }

    public int MaxALtitude
    {
        get { return maxAltitude; }
        set { maxAltitude = value; }
    }
}

public class Aaaa
{
    public static void Main()
    {
        IFlyable bird = new Bird();
        bird.Fly();
    }
}

一个类可以实现多个接口

密封类 sealed与override 限制

使用sealed的类，不能被继承，可以被实例化，可以继承别的类

csharp 复制代码

using System.Diagnostics;

class BaseClass
{
    public virtual void Method()
    {
        Console.WriteLine("基类放发");
    }
}

class DerivedClass : BaseClass
{
    public sealed override void Method()
    {
        Console.WriteLine("派生类方法");
    }
} 

class FurtherDerivedClass : DerivedClass
{
    public override void Method()//错误
    {
        Console.WriteLine("进一步派生类方法");
    }
}

案例1

csharp 复制代码

using System.Diagnostics;
using System.Drawing;


namespace aaaa
{
    internal class Program
    {
        static void Main(string[] args)
        {
            IDrawable[] drawables = new IDrawable[]
            {
                new Circle("红色",10,20,5.0),
            };
        }

      
    }
}

csharp 复制代码

using System;
using System.Collections.Generic;
using System.Text;

namespace aaaa
{
    internal class Circle: Shape,IDrawable,ICalculable
    {
        private double radius;

        public Circle(string color, int x,int y,double radius):base (color,x,y)
        {
            this.radius = radius;
        }

        public void Draw()
        {
            Console.WriteLine($"绘制图形：颜色={Color}，半径={radius}");
        }

        public double GetArea()
        {
            return Math.PI * radius * radius;
        }

        public double GetPerimeter()
        {
            return 2 * Math.PI * radius;
        }

        public override void DisplayInfo()
        {
            base.DisplayInfo();
            Console.WriteLine($"类型：圆，半径：{radius}");
        }
    }
}

csharp 复制代码

using System;
using System.Collections.Generic;
using System.Text;

namespace aaaa
{
    abstract internal class Shape
    {
        public string Color { get; set; }
        public int X { get; set; }
        public int Y { get; set; }

        public Shape (string color,int x,int y)
        {
            Color = color;
            X = x;
            Y = y;
        }

        public virtual void DisplayInfo()
        {
            Console.WriteLine($"颜色：{Color},位置：（{X},{Y}）");
        }
    }
}

csharp 复制代码

using System;
using System.Collections.Generic;
using System.Text;

namespace aaaa
{
    internal interface ICalculable
    {
        double GetArea();
        double GetPerimeter();
    }
}

csharp 复制代码

using System;
using System.Collections.Generic;
using System.Text;

namespace aaaa
{
    internal interface IDrawable
    {
        void Draw();
    }
}

c# 第八章 多态与案例

51 接口interface

密封类 sealed与override 限制

案例1

c# 第八章多态与案例