C#遍历获取文件夹下所有文件

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace DataManageBLL
{
    public class FileHelper
    {
        ///// <summary>
        ///// 遍历获取文件夹下所有文件
        ///// </summary>
        ///// <param name="fileFolder">要搜索的文件夹</param>
        ///// <param name="allfiles">返回的文件列表</param>
        //public static void GetAllFiles(string fileFolder, ref List<string> allfiles)
        //{
        //    DirectoryInfo Dir = new DirectoryInfo(fileFolder);
        //    FileInfo[] files = Dir.GetFiles();
        //    foreach (var fileitem in files)
        //    {
        //        allfiles.Add(fileitem.FullName);
        //    }
        //    DirectoryInfo[] directorys = Dir.GetDirectories();
        //    foreach (var directoryitem in directorys)
        //    {
        //        GetAllFiles(directoryitem.FullName, ref allfiles);
        //    }
        //}

        /// <summary>
        /// 遍历获取文件夹下所有文件
        /// </summary>
        /// <param name="fileFolder">要搜索的文件夹</param>
        /// <param name="allfiles">返回的文件列表</param>
        public static void GetAllFiles(string fileFolder, ref List<string> allfiles, string ext = null, DateTime? startTime = null)
        {
            DateTime lastUploadDateTime = DateTime.MinValue;
            GetAllFiles(fileFolder, ref allfiles, ref lastUploadDateTime, ext, startTime);
        }

        public static void GetAllFilesByImgPath(string decPath, ref List<string> allfiles, ref List<DateTime> lastUploadTimeList, string ext = null, DateTime? startTime = null)
        {
            DirectoryInfo Dir = new DirectoryInfo(decPath);

            DirectoryInfo[] files = Dir.GetDirectories();
            if (files != null && files.Count() > 0)
            {
                if (!string.IsNullOrEmpty(ext))
                {
                    Regex regex = new Regex(ext);
                    files = files.Where(x => x.LastWriteTime > startTime).Where(x => regex.IsMatch(x.Name)).OrderBy(x => x.LastWriteTime).ToArray();
                }
                else
                    files = files.Where(x => x.LastWriteTime > startTime).OrderBy(x => x.LastWriteTime).ToArray();

                if (startTime.HasValue)
                {
                    foreach (var item in files)
                    {
                        allfiles.Add(item.FullName);
                        lastUploadTimeList.Add(item.LastWriteTime);
                    }
                }
            }
        }

        /// <summary>
        /// 遍历获取文件夹下所有文件
        /// </summary>
        /// <param name="fileFolder">要搜索的文件夹</param>
        /// <param name="allfiles">返回的文件列表</param>
        public static void GetAllFiles(string fileFolder, ref List<string> allfiles, ref DateTime lastUploadTime, string ext = null, DateTime? startTime = null)
        {
            DirectoryInfo Dir = new DirectoryInfo(fileFolder);

            FileInfo[] files = new FileInfo[] { };
            if (Dir.Exists)
                files = Dir.GetFiles();
            foreach (var fileitem in files)
            {
                if (startTime == null || (startTime != null && fileitem.LastWriteTime < startTime.Value))
                {
                    if (string.IsNullOrEmpty(ext))
                    {
                        allfiles.Add(fileitem.FullName);
                        if (lastUploadTime < fileitem.LastWriteTime)
                        {
                            lastUploadTime = fileitem.LastWriteTime;
                        }
                    }
                    else
                    {
                        string fileExt = Path.GetExtension(fileitem.FullName);
                        if (fileExt.ToLower() == ext.ToLower())
                        {
                            allfiles.Add(fileitem.FullName);
                            if (lastUploadTime < fileitem.LastWriteTime)
                            {
                                lastUploadTime = fileitem.LastWriteTime;
                            }
                        }
                    }
                }
            }
            DirectoryInfo[] directorys = Dir.GetDirectories();
            foreach (var directoryitem in directorys)
            {
                //if (startTime == null || (startTime != null && directoryitem.LastWriteTime < startTime.Value))
                GetAllFiles(directoryitem.FullName, ref allfiles, ref lastUploadTime, ext, startTime);
            }
        }

        /// <summary>
        /// 遍历获取文件夹下所有文件
        /// </summary>
        /// <param name="fileFolder">要搜索的文件夹</param>
        /// <param name="allfiles">返回的文件列表</param>
        public static void DeleteFiles(string fileFolder, ref List<string> allfiles, string ext = null, DateTime? startTime = null)
        {
            DateTime lastUploadDateTime = DateTime.MinValue;
            DeleteFilesDetail(fileFolder, ref allfiles, ref lastUploadDateTime, ext, startTime);
        }


        /// <summary>
        /// 遍历获取文件夹下所有文件
        /// </summary>
        /// <param name="fileFolder">要搜索的文件夹</param>
        /// <param name="allfiles">返回的文件列表</param>
        public static void DeleteFilesDetail(string fileFolder, ref List<string> allfiles, ref DateTime lastUploadTime, string ext = null, DateTime? startTime = null)
        {
            DirectoryInfo Dir = new DirectoryInfo(fileFolder);

            FileInfo[] files = new FileInfo[] { };
            if (Dir.Exists)
                files = Dir.GetFiles();
            foreach (var fileitem in files)
            {
                if (startTime == null || (startTime != null && fileitem.LastWriteTime < startTime.Value))
                {
                    try
                    {
                        File.Delete(fileitem.FullName);
                    }
                    catch (Exception ex)
                    {
                        continue;
                    }
                }
            }
            DirectoryInfo[] directorys = Dir.GetDirectories();
            foreach (var directoryitem in directorys)
            {
                //if (startTime == null || (startTime != null && directoryitem.LastWriteTime < startTime.Value))
                DeleteFilesDetail(directoryitem.FullName, ref allfiles, ref lastUploadTime, ext, startTime);
            }
        }


        public static void GetAllFilesByPath(string decPath, ref List<string> allfiles, ref List<DateTime> lastUploadTimeList, string ext = null, DateTime? startTime = null)
        {
            DirectoryInfo Dir = new DirectoryInfo(decPath);

            FileInfo[] files = Dir.GetFiles();

            if (files != null && files.Count() > 0)
            {
                files = files.Where(x => x.LastWriteTime > startTime).ToArray();
                if (startTime.HasValue)
                {
                    foreach (var item in files)
                    {
                        if (!string.IsNullOrEmpty(ext))
                        {
                            if (item.Extension.ToLower() == ext.ToLower())
                            {
                                allfiles.Add(item.FullName);
                                lastUploadTimeList.Add(item.LastWriteTime);
                            }
                        }
                        else if (string.IsNullOrEmpty(item.Extension))
                        {
                            allfiles.Add(item.FullName);
                            lastUploadTimeList.Add(item.LastWriteTime);
                        }
                    }
                }
            }

            DirectoryInfo[] fileDireS = Dir.GetDirectories();
            if (fileDireS != null && fileDireS.Count() > 0)
            {
                foreach (var item in fileDireS)
                {
                    GetAllFilesByPath(item.FullName, ref allfiles, ref lastUploadTimeList, ext, startTime);
                }
            }
        }

        /// <summary>
        /// 根据文件路径获取文件字节流
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        public static byte[] GetFileToBytes(string filePath)
        {
            System.IO.Stream sm = GetFile(filePath);
            byte[] buffer;
            if (sm != null)
            {
                buffer = new byte[sm.Length];
                sm.Read(buffer, 0, (int)sm.Length);
                sm.Close();

                return buffer;
            }
            return null;
        }

        /// <summary>
        /// 根据文件路径获取文件流
        /// </summary>
        /// <param name="filePath"></param>
        /// <returns></returns>
        public static Stream GetFile(string filePath)
        {
            if (File.Exists(filePath))
            {
                FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
                return fs;
            }
            return null;
        }

        /// <summary>
        /// 获取目录下的所有子目录
        /// </summary>
        /// <param name="fileFolder"></param>
        /// <returns></returns>
        public static List<string> GetAllDirectorys(string fileFolder, DateTime? startTime = null)
        {
            if (!Directory.Exists(fileFolder))
            {
                //路径不存在
                return null;
            }
            DirectoryInfo Dir = new DirectoryInfo(fileFolder);
            if (startTime == null)
                return Dir.GetDirectories().Select(i => i.FullName).ToList();
            else
                return Dir.GetDirectories().Where(i => i.CreationTime <= startTime).Select(i => i.FullName).ToList();
        }

        /// <summary>
        /// 获取文件的MD5哈希值
        /// </summary>
        /// <param name="filePath">文件名</param>
        /// <returns></returns>
        public static string GetFileMD5Hash(string filePath)
        {
            FileStream get_file = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read);
            MD5CryptoServiceProvider get_md5 = new MD5CryptoServiceProvider();
            byte[] hash_byte = get_md5.ComputeHash(get_file);
            get_file.Close();
            string result = BitConverter.ToString(hash_byte);
            return result.Replace("-", "");
        }

        /// <summary>
        /// 获取某个流的MD5值
        /// 注：流必须先seek(0,begin)
        /// </summary>
        /// <param name="stream"></param>
        /// <returns></returns>
        public static string GetStreamMD5Hash(Stream stream)
        {
            MD5CryptoServiceProvider get_md5 = new MD5CryptoServiceProvider();
            byte[] hash_byte = get_md5.ComputeHash(stream);
            string result = BitConverter.ToString(hash_byte);
            return result.Replace("-", "");
        }

        /// <summary>
        /// 删除文件
        /// </summary>
        /// <param name="filePath"></param>
        public static void FileDelete(string filePath)
        {
            if (File.Exists(filePath))
            {
                File.Delete(filePath);
            }
        }

        /// <summary>
        /// 移动文件（多个）
        /// </summary>
        /// <param name="srcFileFullPathes">源文件（数组）</param>       
        /// <param name="destFileSubPathes">目标文件（数组）</param>        
        /// <param name="isOverwrite">是否覆盖</param>
        /// <returns>
        /// 拷贝后文件的全路径
        /// </returns>
        public static void Move(string[] srcFileFullPathes, string[] destFileFullPathes, bool isOverwrite)
        {
            //参数检查
            if (srcFileFullPathes.Length != destFileFullPathes.Length)
            {
                throw new Exception("[源文件个数]与[目标文件个数]不匹配！");
            }
            //检查目标路径是否存在，不存在就创建
            for (int i = 0; i < destFileFullPathes.Length; i++)
            {
                //路径相同不检查目录
                if (string.Compare(srcFileFullPathes[i], destFileFullPathes[i]) == 0)
                {
                    continue;
                }
                //检查目标文件目录
                CheckDirectory(destFileFullPathes[i]);
            }
            try
            {
                for (int i = 0; i < srcFileFullPathes.Length; i++)
                {
                    //路径相同不移动
                    if (string.Compare(srcFileFullPathes[i], destFileFullPathes[i]) == 0) continue;

                    if (!File.Exists(destFileFullPathes[i]))
                    {
                        //移动文件
                        File.Move(srcFileFullPathes[i], destFileFullPathes[i]);
                    }
                    else if (isOverwrite)
                    { //覆盖
                        File.Delete(destFileFullPathes[i]);

                        File.Move(srcFileFullPathes[i], destFileFullPathes[i]);
                    }
                }
            }
            catch (Exception ex)
            {
                throw;
            }
        }

        /// <summary>
        /// 检查目录是否存在，不存在就创建目录
        /// </summary>
        /// <param name="filePath"></param>
        public static void CheckDirectory(string filePath)
        {
            string directory = filePath.Substring(0, filePath.LastIndexOf(@"\"));
            if (!Directory.Exists(directory))
            {
                try
                {
                    Directory.CreateDirectory(directory);
                }
                catch (Exception ex)
                {
                    throw;
                }
            }

        }

        /// <summary>
        /// 将A文件夹里面的文件和文件夹移动到B文件夹
        /// </summary>
        /// <param name="sourcedirectory"></param>
        /// <param name="destinationdirectory"></param>
        public static void FolderMoveToNewFolder(string sourcedirectory, string destinationdirectory)
        {
            try
            {
                DirectoryInfo nowFolder = new DirectoryInfo(sourcedirectory);
                destinationdirectory = Path.Combine(destinationdirectory, nowFolder.Name);

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

                string[] fileList = Directory.GetFileSystemEntries(sourcedirectory);
                foreach (string file in fileList)
                {
                    if (Directory.Exists(destinationdirectory))
                    {
                        //Directory.Move(file, destinationdirectory);
                        DirectoryInfo folder = new DirectoryInfo(file);
                        string strCreateFileName = destinationdirectory + "\\" + folder.Name;
                        if (!Directory.Exists(strCreateFileName))
                            folder.MoveTo(strCreateFileName);
                        else
                            folder.Delete();
                    }
                    else
                        Directory.Move(sourcedirectory, destinationdirectory);



                    if (File.Exists(file))
                    {
                        File.Move(file, destinationdirectory);
                        //FileInfo fi = new FileInfo(file);
                        //fi.MoveTo(newFolderPath);
                    }
                }
            }
            catch (Exception ex)
            {
            }
        }
    }
}

我一般使用“GetAllFiles”，“DeleteFiles”方法。可以自行决定用哪一个方法