using System;
using System.IO;
class Program
{
    static void Main(string[] args)
    {
        //獲取當(dāng)前運(yùn)行程序的目錄
        string fileDir = Environment.CurrentDirectory;
        Console.WriteLine("當(dāng)前程序目錄：" + fileDir);
        //一個(gè)文件目錄
        string filePath = "C:\\JiYF\\BenXH\\BenXHCMS.xml";
        Console.WriteLine("該文件的目錄：" + filePath);
        string str = "獲取文件的全路徑：" + Path.GetFullPath(filePath);   //-->C:\JiYF\BenXH\BenXHCMS.xml
        Console.WriteLine(str);
        str = "獲取文件所在的目錄：" + Path.GetDirectoryName(filePath); //-->C:\JiYF\BenXH
        Console.WriteLine(str);
        str = "獲取文件的名稱含有后綴：" + Path.GetFileName(filePath);  //-->BenXHCMS.xml
        Console.WriteLine(str);
        str = "獲取文件的名稱沒(méi)有后綴：" + Path.GetFileNameWithoutExtension(filePath); //-->BenXHCMS
        Console.WriteLine(str);
        str = "獲取路徑的后綴擴(kuò)展名稱：" + Path.GetExtension(filePath); //-->.xml
        Console.WriteLine(str);
        str = "獲取路徑的根目錄：" + Path.GetPathRoot(filePath); //-->C:\
        Console.WriteLine(str);
        Console.ReadKey();
    }
}

using System;
using System.IO;
using Microsoft.VisualBasic.Devices;
namespace ChangeSuffix
{
    class Program
    {
        static public string path = @"E:\files";
        static void Main(string[] args)
        {
            Computer myComputer = new Computer();
            DirectoryInfo dir = new DirectoryInfo(path);
            FileInfo[] files = dir.GetFiles();
            foreach (var file in files)
            {
                string newName = file.Name.Replace(".xlsx", ".txt");      //.xlsx修改成.txt
                if(newName != file.Name)
                    myComputer.FileSystem.RenameFile(file.FullName, newName);
            }
            Console.ReadLine();
        }
    }
}