此类用于处理文件路径

using System;
using System.IO;

namespace PathTest
{
    class Program
    {
        static void Main(string[] args)
        {
            string s;
            Console.WriteLine("Path类的使用");

            string path1 = @"D:\path1";
            string path2 = @"path2";
            string file = @"test.txt";
            string filePath = @"D:\path\test.txt";

            Console.WriteLine("path1={0}", path1);
            Console.WriteLine("path2={0}", path2);
            Console.WriteLine("file={0}", file);
            Console.WriteLine("filePath={0}", filePath);
            Console.WriteLine();

            //更改扩展名
            s = Path.ChangeExtension(filePath, "bin");
            Console.WriteLine("ChangeExtension={0}", s);

            //合并路径
            s = Path.Combine(path1, path2);
            Console.WriteLine("Combine={0}", s);

            //获取目录名
            s = Path.GetDirectoryName(filePath);
            Console.WriteLine("GetDirectoryName={0}", s);

            //获取扩展名
            s = Path.GetExtension(filePath);
            Console.WriteLine("GetExtension={0}", s);

            //获取文件名
            s = Path.GetFileName(filePath);
            Console.WriteLine("GetFileName={0}", s);

            //获取不带扩展名的文件名
            s = Path.GetFileNameWithoutExtension(filePath);
            Console.WriteLine("GetFileNameWithoutExtension={0}", s);

            //获取路径的完全限定名
            s = Path.GetFullPath(path2);
            Console.WriteLine("GetFullPath={0}", s);

            //获取根目录
            s = Path.GetPathRoot(filePath);
            Console.WriteLine("GetPathRoot={0}", s);

            //返回随机文件名
            s = Path.GetRandomFileName();
            Console.WriteLine("GetRandomFileName={0}", s);

            //随机创建临时文件名
            s = Path.GetTempFileName();
            Console.WriteLine("GetTempFileName={0}", s);

            //返回当前系统临时文件夹路径
            s = Path.GetTempPath();
            Console.WriteLine("GetTempPath={0}", s);

            //路径是否包含文件扩展名
            bool b = Path.HasExtension(filePath);
            Console.WriteLine("HasExtension={0}", b);

            //判断是否为绝对路径
            b = Path.IsPathRooted(filePath);
            Console.WriteLine("IsPathRooted={0}", b);

            //获取不允许在文件名中使用的字符数组
            char[] chars = Path.GetInvalidFileNameChars();

            //获取不允许在路径中使用的字符数组
            chars = Path.GetInvalidPathChars();

            Console.Read();
        }
    }
}

运行效果