C# 自定义类型实现foreach 迭代

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;
namespace Foreach
{
    class Program
    {
        static void Main(string[] args)
        {
            person[] persons = new person[]{
                new person("aaa",20),
                new person("bbb",21),
                new person("ccc",22),
            };

            People peopleList = new People(persons);
            foreach (var item in peopleList)
            {
               
                Console.WriteLine(item);
            }
            Console.ReadLine();
            //person p = new person("aaa", 12);  //调用了重写的函数方法
            //Console.WriteLine(p.ToString());
        }
    }
    public class person
    {
        string Name;
        int Age;
        public person(string name,int age)
        {
            Name = name;
            this.Age = age;
        }
        public override string ToString()
            //重写ToString()方法
        {
            return "Name:" + this.Name + "\tAge:" + this.Age;
        }

    }

    public class PeopleEnum : System.Collections.IEnumerator
    {
        private person[] _people;    //要控制的people
        int postion = -1;
        public PeopleEnum(person[] list)
        {
            _people = list;
        }
        public object Current
        {
            //get { throw new NotImplementedException(); }
            get {
                return _people[postion];
            }
        }

        public bool MoveNext()
        {
            //throw new NotImplementedException();
            postion++;
            return (postion < _people.Length);
        }

        public void Reset()
        {
            //throw new NotImplementedException();
            postion = -1;
        }
    }
    public class People : IEnumerable
    {
        private person[] _people;
        public People(person[] pArray)
        {
            _people = new person[pArray.Length];
            for (int i = 0; i < pArray.Length; i++)
            {
                _people[i] = pArray[i];
            }
        }
        public IEnumerator GetEnumerator()
        {
            //throw new NotImplementedException();
            return new PeopleEnum(_people);
        }
    }
}