创建控制台应用程序，重载运算符+

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace OPeratorOvlApplication
{
    class Box
    {
        private double length;//长度
        private double breadth;//宽度
        private double height;//高度
        public double getVolume()
        {
            return length * breadth * height;

        }
        public void setLength(double len)
        {
            length = len;
        }
        public void setBreadth(double bre)
        {
            breadth = bre;

        }
        public void setHeigth(double hei)
        {
            height = hei;
        }
        public static Box operator+(Box b,Box c)//重载+运算符吧两个Box对象加起来
        {
            Box box = new Box();
            box.length = b.length + c.length;
            box.height = b.height + c.height;
            box.breadth = b.breadth + c.breadth;
            return box;
        }
    }
    class Program
    {
        static void Main(string[] args)
        {
            Box Box1 = new Box();//box1
            Box1.setLength(6.0);
            Box1.setBreadth(7.0);
            Box1.setHeigth(5.0);

            Box Box2 = new Box();//box2
            Box2.setLength(12.0);
            Box2.setBreadth(13.0);
            Box2.setHeigth(10.0);
            

            double volume = Box1.getVolume();
            Console.WriteLine("Box1体积:{0}",volume);
            volume = Box2.getVolume();
            Console.WriteLine("Box2体积:{0}", volume);

            Box Box3 = new Box();//box3
            Box3 = Box1 + Box2;
            volume = Box3.getVolume();
            Console.WriteLine("Box3体积:{0}", volume);
            Console.ReadKey();

        }
    }
}