Csharp/C#核心/Lesson18_多态-抽象类和抽象方法练习/Program.cs

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();
        }
    }
}