using System;
using System.Collections;
class App{
    public static void Main()
    {
         foreach (int number in SomeNumbers())
         {
             Console.WriteLine(number.ToString() + " ");
         }

        //Console.WriteLine(SomeNumbers().MoveNext());
        // Output: 3 5 8
        
 
// Console.ReadKey();
    }

    public static IEnumerable SomeNumbers()
    {
        yield return 3;
        yield return 5;
        yield return 8;
    }
}

C# 叠代器