using System;
using System.Collections;
using System.IO;
using Microsoft.Office.Interop.PowerPoint;
using Microsoft.Office.Core;
using System.Windows.Forms;
using System.Threading;

namespace test
{
  public class Persons : System.Collections.IEnumerable
  {
    #region IEnumerable 成员

    public System.Collections.IEnumerator GetEnumerator()
    {
      yield return "1";
      Thread.Sleep(5000);
      yield return "2";
      Thread.Sleep(5000);
      yield return "3";
      Thread.Sleep(5000);
      yield return "4";
      Thread.Sleep(5000);
      yield return "5";
      Thread.Sleep(5000);
      yield return "6";
    }

    #endregion
  }

  class program
  {
    static void Main()
    {
      Persons arrPersons = new Persons();
      foreach (string s in arrPersons)
      {
        System.Console.WriteLine(s);
      }

      System.Console.ReadLine();
    }
  }  
}