代码如下
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace 任务一
{
    class Program
    {
        
        static void Main(string[] args)
        {
          string s;
            Console.WriteLine("请输入一个字符串");
            s= Console.ReadLine();
            Console.WriteLine(getstring(s));
            Console.ReadKey();
            }
        static string getstring(string s)
        {
            string[] a = new string[] { "a", "e", "i", "o", "u" };
           
            for (int i = 0; i < a.Length; i++)
            {
                if (s==a[i])
                {
                    Console.WriteLine("您输入了一个元音");
                }
              else
                {
                    Console.WriteLine("这不是一个元音");
                }

            }
            return null;
           
         
        }
        
    }
   
}

恩这个我明白但是我想得到数组中的元素再进行判断

结果是我想要的谢了啊呵呵