Thao tác với đường dẫn Path và DriveInfo trong C#

using System;
using System.IO;

namespace MinhHoangBlog
{
	class Program
	{
		static void Main(string[] args)
		{
			string goodFileName = @"D:\MinhHoangBlog\minhhn.com\myFile.txt";
			string badFileName = @"D:\MinhHoangBlog\minhhn.com\";
			string result;

			result = Path.ChangeExtension(goodFileName, ".old");
			// output "D:\MinhHoangBlog\minhhn.com\myFile.old"

			result = Path.ChangeExtension(goodFileName, "");
			// output "D:\MinhHoangBlog\minhhn.com\myFile."

			result = Path.ChangeExtension(badFileName, ".old");
			// output "D:\MinhHoangBlog\minhhn.com\.old"

			result = Path.GetDirectoryName(goodFileName);
			// output "D:\\MinhHoangBlog\\minhhn.com"

			result = Path.GetExtension(goodFileName);
			// output ".txt"

			result = Path.GetFileName(goodFileName);
			// output "myFile.txt"

			result = Path.GetFileNameWithoutExtension(goodFileName);
			// output "myFile"

			result = Path.GetFullPath(goodFileName);
			// output "D:\\MinhHoangBlog\\minhhn.com\\myFile.txt"

			result = Path.GetPathRoot(goodFileName);
			// output "D:\\"

			result = Path.GetTempFileName();
			// output "C:\\Users\\pc\\AppData\\Local\\Temp\\tmpE185.tmp"

			result = Path.GetTempPath();
			// output "C:\\Users\\pc\\AppData\\Local\\Temp\\"

			string fileName = @"C:\mydir\myfile.ext";
			string uncPath = @"\\myPc\mydir\myfile";
			string relativePath = @"mydir\sudir\";
			bool isFlg;

			isFlg = Path.HasExtension(fileName);
			// output "true"

			isFlg = Path.HasExtension(uncPath);
			// output "false"

			isFlg = Path.IsPathRooted(fileName);
			// output "true"

			isFlg = Path.IsPathRooted(uncPath);
			// output "true"

			isFlg = Path.IsPathRooted(relativePath);
			// output "false"

			// Get current working directory (..\bin\Debug)
			string workingDirectory = Environment.CurrentDirectory;

			// Get the current PROJECT directory
			string projectDirectory = Directory.GetParent(workingDirectory).Parent.FullName;

			// Create specific path file
			string csvPath = string.Format(@"{0}\CsvFile\Sample.csv", projectDirectory);

			// Remove the last character if it's DirectorySeparatorChar
			result = badFileName.TrimEnd(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
			// badFileName "D:\\MinhHoangBlog\\minhhn.com\\"
			// output "D:\\MinhHoangBlog\\minhhn.com"

			Console.ReadKey();
		}
	}
}