C#输入字母+数字的字符串 统计数字出现的位置

using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Collections;



namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            Console.WriteLine("输入由字母和数字组成的字符串：");
            String x = Console.ReadLine();
            char[] chars = x.ToCharArray();
            int int_Indexof = 0;
            Array.ForEach(chars, z =>
            {
                if (Char.IsDigit(z))
                {
                    Console.WriteLine("数字:" + z + ",位置:" + int_Indexof);
                }

                int_Indexof++;
            });
        }
    }