GetEnumerator()；yield

 1 publicclass List
 2 {
 3     public static IEnumerable Power(int number（2）, int exponent（8）)//使用yield return 使得返回值是一个迭代器类型
 4     {
 5         int counter =0;
 6         int result =1;
 7         while (counter++< exponent)
 8         {
 9             result = result * number;
10             yield return result;
11         }
12     }
13 
14 staticvoid Main()
15     {
16         foreach (int i in Power(2, 8))
17         {
18             Console.Write("{0} ", i);
19         }
20     }
21 }

/*
输出：
Output:
2 4 8 16 32 64 128 256       //
*/

 1  class Program
 2  {
 3  staticvoid Main(string[] args)
 4      {
 5  foreach (var item in Person.Run())
 6          {
 7              Console.WriteLine(item);
 8          }
 9      }
10 }
11 class Person
12 {
13 public static IEnumerable<int> Run()
14     {
15          List<int> list = new List<int>();
16 foreach (var item in list)
17         {
18 yieldreturn item;
19         }
20    }
21  }