关键字yiel的使用方法

在迭代器块中用于向枚举数对象提供值或发出迭代结束信号。它的形式为下列之一：

 

yield return <expression>;
yield break;

using System;
using System.Collections;
public class List
{
    public static IEnumerable Power(int number, int exponent)
    {
        int counter = 0;
        int result = 1;
        while (counter++ < exponent)
        {
            result = result * number;
            yield return result;
        }
    }

    static void Main()
    {
        // Display powers of 2 up to the exponent 8:
        foreach (int i in Power(2, 8))
        {
            Console.Write("{0} ", i);
        }
    }
}