简单迭代器的实现

例子1：

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

namespace test
{
　　//实现了IEnumerable接口，用于实现迭代
    public class DaysOfTheWeek : IEnumerable
    {
        string[] m_Days = { "Sun", "Mon", "Tue", "Wed", "Thur", "Fri", "Sat" };

 
　　　　//实现了迭代的函数
        public IEnumerator GetEnumerator()
        {
            for (int i = 0; i < m_Days.Length; i++)
            {
                yield return m_Days[i];
            }
        }
    }

    class TestDaysOfTheWeek
    {
        static void Main()
        {
            // Create an instance of the collection class
            DaysOfTheWeek week = new DaysOfTheWeek();

            // Iterate with foreach
            foreach (string day in week)
            {
                System.Console.Write(day + " ");
            }
        }
    }

}

 

例子2：

 

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

namespace ForeachTest
{
    public class Car
    {
        public  string CarType;
        public  int CarYear;
        public Car(string type,int year)
        {
            CarType = type;
            CarYear = year;
        }
    }
    public class Garage:IEnumerable
    {
        private Car[] CarArray = new Car[4];
        public Garage()
        {
            CarArray[0] = new Car("Rusty", 30);
            CarArray[1] = new Car("Clunker", 55);
            CarArray[2] = new Car("Zippy", 30);
            CarArray[3] = new Car("Fred", 30);
        }
        public IEnumerator GetEnumerator()
        {
            //return CarArray.GetEnumerator();

            yield return CarArray[0];
            yield return CarArray[1];
            yield return CarArray[2];
            yield return CarArray[3];
        }

    }
    class Program
    {
        static void Main(string[] args)
        {
            Garage garage = new Garage();
            foreach (Car car in garage)
            {
                Console.WriteLine("{0}---{1}",car.CarType,car.CarYear);
            }
        }
    }
}