C#，抽象类和抽象方法，关于多态的应用

Question

有一种立体图形叫直棱柱，直棱柱的上下底面可以是圆形、三角形、四边形等。

（1）创建一个直棱柱抽象类RightPrism（构造方法为Shape类和double型高），以及抽象方法（计算体积GetVolume，计算侧面积GetLateralArea ）。

（2）发挥面向对象的思想，封装出圆柱体（Cylinder）、三棱柱（TrianglarPrism）、正方体(Cube)、长方体(Cuboid)对应的类。

（3）创建各个形状的实例，在控制台中打印出各种形状的侧面积(LateralArea)和体积（Volume）。

Answer 1

 

using System;

namespace RightPrism
{
    public abstract class Shape
    {
        public abstract double GetArea();
        public abstract double GetCircumference();
    }
    public class Circle : Shape
    {
        public double x { get; set; }
        public override double GetArea()
        {
            return Math.Round(Math.PI * Math.Pow(x, 2), 4);
        }
        public override double GetCircumference()
        {
            return Math.Round(2 * x * Math.PI, 4);
        }
    }
    public class Rectangle : Shape
    {
        public double x { get; set; }
        public double y { get; set; }
        public Rectangle(double x, double y)
        {
            this.x = x; this.y = y;
        }
        public override double GetArea()
        {
            return x * y;
        }
        public override double GetCircumference()
        {
            return (x + y) * 2;
        }
    }
    public class Square : Rectangle { public Square(double x) : base(x, x) { } }

    public class Triangle : Shape
    {
        public double x { get; set; }
        public double y { get; set; }
        public double z { get; set; }
        public Triangle(double x, double y, double z)
        {
            if (x + y > z && x + z > y && y + z > x)
            {
                this.x = x; this.y = y; this.z = z;
            }
            else Console.WriteLine(x + "," + y + "," + z + "无法构成三角形！");
        }
        public override double GetArea()
        {
            double p = (x + y + z) / 2;
            return Math.Round(Math.Sqrt((p * (p - x) * (p - y) * (p - z))), 4);//保留4位小数，保留位数改这里
        }
        public override double GetCircumference()
        {
            return x + y + z;
        }
    }

    public abstract class RightPrism
    {
        public abstract double GetVolume();
        public abstract double GetLateralArea();
        public Shape p { get; set; }
        public double height { get; set; }
        public RightPrism(Shape p, double height)
        {
            this.p = p;
            this.height = height;
        }
    }
    public class Cylinder : RightPrism
    {
        public Cylinder(Shape p, double height) : base(p, height) { }
        public override double GetLateralArea() { return Math.Round(p.GetCircumference() * height, 4); }
        public override double GetVolume() { return Math.Round(p.GetArea() * height, 4); }
    }
    public class TrianglarPrism : RightPrism
    {
        public TrianglarPrism(Shape p, double height) : base(p, height) { }
        public override double GetLateralArea() { return Math.Round(p.GetCircumference() * height, 4); }
        public override double GetVolume() { return Math.Round(p.GetArea() * height, 4); }
    }
    public class Cube : RightPrism
    {
        public Cube(Shape p, double height) : base(p, height) { }
        public override double GetLateralArea() { return Math.Round(p.GetCircumference() * height, 4); }
        public override double GetVolume() { return Math.Round(p.GetArea() * height, 4); }
    }
    public class Cuboid : RightPrism
    {
        public Cuboid(Shape p, double height) : base(p, height) { }
        public override double GetLateralArea() { return Math.Round(p.GetCircumference() * height, 4); }
        public override double GetVolume() { return Math.Round(p.GetArea() * height, 4); }
    }

    class Program
    {
        static void Main(string[] args)
        {
            RightPrism o = new Cylinder(new Circle { x = 5 }, 5);
            Console.WriteLine(String.Format("圆柱体：{0,-15}{1}", "侧面积：" + o.GetLateralArea(), "体积：" + o.GetVolume())); 
            o = new TrianglarPrism(new Triangle (3,4,5), 5);
            Console.WriteLine(String.Format("三棱柱：{0,-15}{1}", "侧面积：" + o.GetLateralArea(), "体积：" + o.GetVolume()));
            o = new Cube(new Square(3), 5);
            Console.WriteLine(String.Format("正方体：{0,-15}{1}", "侧面积：" + o.GetLateralArea(), "体积：" + o.GetVolume()));
            o = new Cube(new Rectangle(3,4), 5);
            Console.WriteLine(String.Format("长方体：{0,-15}{1}", "侧面积：" + o.GetLateralArea(), "体积：" + o.GetVolume()));
            Console.ReadKey();
        }
    }
    
}