//如果文件夹路径不存在则创建文件夹
if (!Directory.Exists(path))
    Directory.CreateDirectory(path);

        public void createdir(string fullpath)
        {
            if (!File.Exists(fullpath))
            {
                string dirpath = fullpath.Substring(0, fullpath.LastIndexOf('\\'));
                //string[] pathes = dirpath.Split('\\');
                string[] pathes = fullpath.Split('\\');
                if (pathes.Length > 1)
                {
                    string path = pathes[0];
                    for (int i = 1; i < pathes.Length; i++)
                    {
                        path += "\\" + pathes[i];
                        //如果文件夹路径不存在则创建文件夹
                        if (!Directory.Exists(path))
                            Directory.CreateDirectory(path);
                    }
                }
            }
        }

Directory.Delete(path, true)

            var list = new string []{ };
            string path = @"D:\公司SVN";
            //获取路径下所有文件
            list = Directory.GetFiles(path);
            //获取路径下所有文件夹
            list = Directory.GetDirectories(path);
            //获取路径下所有文件+文件夹
            list = Directory.GetFileSystemEntries(path);
            //获取路径下所有文件（包含子集文件）
            list = Directory.GetFiles(path, "*.*", SearchOption.AllDirectories);
            //获取路径下所有文件夹（包含子集文件夹）
            list = Directory.GetDirectories(path, "*.*", SearchOption.AllDirectories);
            //获取路径下所有文件+文件夹（包含子集文件+子集文件夹）
            list = Directory.GetFileSystemEntries(path, "*.*", SearchOption.AllDirectories);

  private static void DirectoryCopy(string sourceDirName, string destDirName)
        {
            DirectoryInfo dir = new DirectoryInfo(sourceDirName);
            DirectoryInfo[] dirs = dir.GetDirectories();

            if (!Directory.Exists(destDirName))
                Directory.CreateDirectory(destDirName);


            foreach (FileInfo file in dir.GetFiles())
                file.CopyTo(Path.Combine(destDirName, file.Name), true);

            foreach (DirectoryInfo subdir in dirs)
                DirectoryCopy(subdir.FullName, Path.Combine(destDirName, subdir.Name));

        }

Install-Package  Microsoft.VisualBasic

string sourcePath = @"D:\test";
string targetPath = @"D:\test_new";
//true：目录中具有相同的文件则覆盖
Microsoft.VisualBasic.FileIO.FileSystem.CopyDirectory(sourcePath, targetPath,true);

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

            //获取当前运行程序的目录
            string fileDir = Environment.CurrentDirectory;
            Console.WriteLine("当前程序目录："+fileDir);

            //一个文件目录
            string filePath = "C:\\JiYF\\BenXH\\BenXHCMS.xml";
            Console.WriteLine("该文件的目录："+filePath);

            string str = "获取文件的全路径：" + Path.GetFullPath(filePath);   //-->C:\JiYF\BenXH\BenXHCMS.xml
            Console.WriteLine(str);
            str = "获取文件所在的目录：" + Path.GetDirectoryName(filePath); //-->C:\JiYF\BenXH
            Console.WriteLine(str);
            str = "获取文件的名称含有后缀：" + Path.GetFileName(filePath);  //-->BenXHCMS.xml
            Console.WriteLine(str);
            str = "获取文件的名称没有后缀：" + Path.GetFileNameWithoutExtension(filePath); //-->BenXHCMS
            Console.WriteLine(str);
            str = "获取路径的后缀扩展名称：" + Path.GetExtension(filePath); //-->.xml
            Console.WriteLine(str);
            str = "获取路径的根目录：" + Path.GetPathRoot(filePath); //-->C:\
            Console.WriteLine(str);
            Console.ReadKey();

        }
    }

            //path是完整路径，要包含文件的后缀名
            string path = @"C:\1.txt";
            //判断文件是否存在，不存在就创建
            if (!File.Exists(path))
            {

                //创建一个 UTF-8 编码text文件
                File.CreateText(path);


                //创建一个文件
                //File.Create(path);
            }

using System.IO;

namespace ConsoleApp2
{
    class Program
    {
        static void Main(string[] args)
        {
            //写入文本，不是追加，是清空在写入
            string path = @"C:\1.txt";
            string[] lines = { "First line", "Second line", "Third line" };
            File.WriteAllLines(path, lines);
            File.WriteAllText(path, "AAAAAAAAAAAAAAAA");

            //追加写入文本
            using (StreamWriter sw = new StreamWriter(path, true))
            {
                sw.WriteLine("Fourth line");
            }
            using (StreamWriter sw = File.AppendText(path))
            {
                sw.Write(12345);
            }

        }
    }
}

        public Stream FileToStream(string fileFullName)
        {
            using (FileStream fs = new FileStream(fileFullName, FileMode.OpenOrCreate))
            {
                byte[] bytes = new byte[fs.Length];
                fs.Read(bytes, 0, bytes.Length);
                fs.Close();
                return new MemoryStream(bytes);
            }
        }

        public void WriteFile(string fileFullName, byte[] bytes)
        {
            if (bytes == null)
                return;
            using (FileStream fs = new FileStream(fileFullName, FileMode.OpenOrCreate))
            {
                fs.Write(bytes, 0, bytes.Length);
                fs.Close();
            }

            #region 第二种
            /*
                using (MemoryStream m = new MemoryStream(bytes))
                using (FileStream fs = new FileStream(fileFullName, FileMode.OpenOrCreate))
                {
                    m.WriteTo(fs);
                }
             */
            #endregion

        }

        /// <summary>
        /// 将 Stream 转成 byte[]
        /// </summary>
        /// <param name="bytes"></param>
        /// <returns></returns>
        public byte[] StreamToBytes(Stream stream)
        {
            byte[] bytes = new byte[stream.Length];
            stream.Read(bytes, 0, bytes.Length);
            stream.Seek(0, SeekOrigin.Begin);
            stream.Flush();
            stream.Close();
            return bytes;

        }

        /// <summary>
        /// 将 byte[] 转成 Stream
        /// </summary>
        /// <param name="bytes"></param>
        /// <returns></returns>
        public Stream BytesToStream(byte[] bytes)
        {
            return new MemoryStream(bytes);
        }