IEnumerable接口与IEnumerator接口

通过一个例子来看
-------------------------------------------------------Student.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;
namespace ConsoleApplication6
{
public class Student:IEnumerable
{
//数组
public string[] s;
//索引器
public int i;
public Student(string[] str)//构造函数，初始化数组
{
s = str;
}
public IEnumerator GetEnumerator()//迭代器
{
return s.GetEnumerator();
}
}
}

-------------------------------------------------------StiAll.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Collections;
namespace ConsoleApplication6
{
public class StiAll:IEnumerator
{
//student对象
Student s;
//游标
int i = -1;
public StiAll(Student ss)//构造函数，初始化student对象
{
this.s = ss;
}

public object Current//获取当前的项（只读属性）
{
get { return s.s[i]; }
}
public bool MoveNext()//将游标的位置向前移动
{
if (i<s.s.Length-1)//如果在s数组的长度范围之内就返回true
{
i++;
return true;
}
else
{
return false;
}
}
public void Reset()//初始化游标
{
i = -1;
}
}
}

-------------------------------------------------------主程序

Student s = new Student(new string[] { "吕蒙", "周泰", "黄盖" });//实例化Student对象
//第一种方式遍历
foreach (var item in s)
{
Console.WriteLine(item);//输出吕蒙，周泰，黄盖
}
//第二种方式遍历
StiAll sa = new StiAll(s);
while (sa.MoveNext())
{
Console.WriteLine(sa.Current);//输出吕蒙，周泰，黄盖
}
Console.ReadKey();