修改文件夹中的文件名

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

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

            DirectoryInfo dir = new DirectoryInfo(args[0]);
            bool test = dir.Exists;
            if (dir.Exists)
            {
                foreach (FileInfo file in dir.GetFiles())
                {
                    File.Move(args[0] + "\" + file.Name, args[0] + "\" + "accccc.txt");
                    break;
                }
            }
            else
            {
                Console.WriteLine("The directory {0} does not exist", args[0]);
            }

        }            
    }
}