[作业10-11]1.编写一个类立方体Cub，让其实现IEnumarable接口，细节是令其可以遍历迭代长宽高，并做一个客户代码验证。

Cub.cs代码:

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

namespace ConsoleApplication1
{

    public class Cub : IEnumerable       //声明立方体Cub类继承IEnumerable接口！
    {
        int length;   //声明长度！
        int width;     //声明宽度！
        int height;    //声明高度！

        public void cub(int length, int width, int height)   //声明构造函数，并用长宽高签名！
        {
            this.length = length;
            this.width = width;
            this.height = height;
        }

        #region IEnumerable 成员

        public IEnumerator GetEnumerator()
        {
            return new CubEnumerator(this);   //返回当前枚举对象！
        }

        #endregion
        public int this[uint i]    //索引器！
        {
            get
            {
                switch (i)
                {
                    case 0:
                        return length;
                    case 1:
                        return width;
                    case 2:
                        return height;
                    default:
                        throw new IndexOutOfRangeException(
                           "Attempt to retrieve Vector element" + i);
                }
            }
            set
            {
                switch (i)
                {
                    case 0:
                        length = value;
                        break;
                    case 1:
                        width = value;
                        break;
                    case 2:
                        height = value;
                        break;
                    default:
                        throw new IndexOutOfRangeException(
                           "Attempt to set Vector element" + i);
                }
            }
        }

    }

 

    #region enumerator class
    public class CubEnumerator : IEnumerator       //声明CubEnumerator类，并继承接口IEnumerator！
    {
        Cub theCub;      // Cub object that this enumerato refers to
        int location;   // which element of theCub the enumerator is currently referring to

        public CubEnumerator(Cub theCub)
        {
            this.theCub = theCub;
            location = -1;
        }

        public bool MoveNext()
        {
            ++location;
            return (location > 2) ? false : true;
        }

        public object Current
        {
            get
            {
                if (location < 0 || location > 2)
                    throw new InvalidOperationException(
                       "The enumerator is either before the first element or " +
                       "after the last element of the Vector");
                return theCub[(uint)location];
            }
        }

        public void Reset()
        {
            location = -1;
        }
    }
    #endregion
}

Program.cs代码：

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            Cub c = new Cub();       //实例化一个Cub类！
            c.cub(2, 3, 4);          //初始化长、宽、高的值！
        
            foreach (int temp in c)   //迭代集合c！
            {
                foreach (int next in c)    //迭代集合c!
                {
                    Console.Write("  " + next);
                }
                Console.WriteLine(temp);
            }
        }
    }
}