使用.net FtpWebRequest 实现FTP常用功能 上传 下载 获取文件列表 移动 切换目录 改名 .

平时根本没时间搞FTP什么的，现在这个项目需要搞FTP，为什么呢，我给大家说下项目背景，我们的一个应用程序上需要上传图片，但是用户部署程序的服务器上不让上传任何东西，给了我们一个FTP账号和密码，让我们把图片保存到另一台所谓的文件服务器上面。

建立ftp通信，写入文件流，ok ，  但是显示的时候就麻烦了，不能直接写<img src = "ftp://121.131.131.1" />这样的代码啊，因为这样写的话，你浏览的时候还要登陆Ftp账户，每次都要弹出一个用户登陆框，So，决定显示图片的时候再把图片读出来放到内存里，然后输出到Response里面，把Response的ContentType设置成相对应的类型，比如 Image/gif   Image/jpeg  Image/png   Appliaction/pdf.

下面是一些常用的ftp操作文件的方法（摘抄于网络） 不过获取文件  和获取文件夹和文件 有问题，本人已重写过

using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using System.Net;
using System.Windows.Forms;
using System.Globalization;
namespace FtpTest1
{
    public class FtpWeb
    {
        string ftpServerIP;
        string ftpRemotePath;
        string ftpUserID;
        string ftpPassword;
        string ftpURI;
        /// <summary>
        /// 连接FTP
        /// </summary>
        /// <param name="FtpServerIP">FTP连接地址</param>
        /// <param name="FtpRemotePath">指定FTP连接成功后的当前目录, 如果不指定即默认为根目录</param>
        /// <param name="FtpUserID">用户名</param>
        /// <param name="FtpPassword">密码</param>
        public FtpWeb(string FtpServerIP, string FtpRemotePath, string FtpUserID, string FtpPassword)
        {
            ftpServerIP = FtpServerIP;
            ftpRemotePath = FtpRemotePath;
            ftpUserID = FtpUserID;
            ftpPassword = FtpPassword;
            ftpURI = "ftp://" + ftpServerIP + "/" + ftpRemotePath + "/";
        }
        /// <summary>
        /// 上传
        /// </summary>
        /// <param name="filename"></param>
        public void Upload(string filename)
        {
            FileInfo fileInf = new FileInfo(filename);
            string uri = ftpURI + fileInf.Name;
            FtpWebRequest reqFTP;
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
            reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
            reqFTP.KeepAlive = false;
            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
            reqFTP.UseBinary = true;
            reqFTP.ContentLength = fileInf.Length;
            int buffLength = ;
            byte[] buff = new byte[buffLength];
            int contentLen;
            FileStream fs = fileInf.OpenRead();
            try
            {
                Stream strm = reqFTP.GetRequestStream();
                contentLen = fs.Read(buff, , buffLength);
                while (contentLen != )
                {
                    strm.Write(buff, , contentLen);
                    contentLen = fs.Read(buff, , buffLength);
                }
                strm.Close();
                fs.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "Upload Error --> " + ex.Message);
            }
        }
        /// <summary>
        /// 下载
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="fileName"></param>
        public void Download(string filePath, string fileName)
        {
            FtpWebRequest reqFTP;
            try
            {
                FileStream outputStream = new FileStream(filePath + "//" + fileName, FileMode.Create);
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                long cl = response.ContentLength;
                int bufferSize = ;
                int readCount;
                byte[] buffer = new byte[bufferSize];
                readCount = ftpStream.Read(buffer, , bufferSize);
                while (readCount > )
                {
                    outputStream.Write(buffer, , readCount);
                    readCount = ftpStream.Read(buffer, , bufferSize);
                }
                ftpStream.Close();
                outputStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "Download Error --> " + ex.Message);
            }
        }
        /// <summary>
        /// 删除文件
        /// </summary>
        /// <param name="fileName"></param>
        public void Delete(string fileName)
        {
            try
            {
                string uri = ftpURI + fileName;
                FtpWebRequest reqFTP;
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                reqFTP.KeepAlive = false;
                reqFTP.Method = WebRequestMethods.Ftp.DeleteFile;
                string result = String.Empty;
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                long size = response.ContentLength;
                Stream datastream = response.GetResponseStream();
                StreamReader sr = new StreamReader(datastream);
                result = sr.ReadToEnd();
                sr.Close();
                datastream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "Delete Error --> " + ex.Message + "  文件名:" + fileName);
            }
        }
        /// <summary>
        /// 获取当前目录下明细(包含文件和文件夹)
        /// </summary>
        /// <returns></returns>
        public string[] GetFilesDetailList()
        {
            string[] downloadFiles;
            try
            {
                StringBuilder result = new StringBuilder();
                FtpWebRequest ftp;
                ftp = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI));
                ftp.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                ftp.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
                WebResponse response = ftp.GetResponse();
                StreamReader reader = new StreamReader(response.GetResponseStream());
                string line = reader.ReadLine();
                line = reader.ReadLine();
                line = reader.ReadLine();
                while (line != null)
                {
                    result.Append(line);
                    result.Append("/n");
                    line = reader.ReadLine();
                }
                result.Remove(result.ToString().LastIndexOf("/n"), );
                reader.Close();
                response.Close();
                return result.ToString().Split('/n');
            }
            catch (Exception ex)
            {
                downloadFiles = null;
                Insert_Standard_ErrorLog.Insert("FtpWeb", "GetFilesDetailList Error --> " + ex.Message);
                return downloadFiles;
            }
        }
         /// <summary>
        /// 获取FTP文件列表包括文件夹
        /// </summary>
        /// <returns></returns>
        private string[] GetAllList(string url,string userid,string password)
        {
            List<string> list = new List<string>();
            FtpWebRequest req = (FtpWebRequest)WebRequest.Create(new Uri(url));
            req.Credentials = new NetworkCredential(userid, password);
            req.Method = WebRequestMethods.Ftp.ListDirectory;
            req.UseBinary = true;
            req.UsePassive = true;
            try
            {
                using (FtpWebResponse res = (FtpWebResponse)req.GetResponse())
                {
                    using (StreamReader sr = new StreamReader(res.GetResponseStream()))
                    {
                        string s;
                        while ((s = sr.ReadLine()) != null)
                        {
                            list.Add(s);
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                throw (ex);
            }
            return list.ToArray();
        }
        /// <summary>
        /// 获取当前目录下文件列表 不包括文件夹
        /// </summary>
        /// <returns></returns>
        public string[] GetFileList(string url,string userid,string password)
        {

            StringBuilder result = new StringBuilder();
            FtpWebRequest reqFTP;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(url));
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(userid, password);
                reqFTP.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
                WebResponse response = reqFTP.GetResponse();
                StreamReader reader = new StreamReader(response.GetResponseStream());
                string line = reader.ReadLine();
                    while (line != null)
                    {

                        if (line.IndexOf("<DIR>")==-)
                        {
                            result.Append(Regex.Match(line, @"[/S]+ [/S]+", RegexOptions.IgnoreCase).Value.Split(' ')[]);
                            result.Append("/n");
                        }
                        line = reader.ReadLine();
                    }
                result.Remove(result.ToString().LastIndexOf('/n'), );
                reader.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                throw (ex);
            }
            return result.ToString().Split('/n');
        }

        /// <summary>
        /// 判断当前目录下指定的子目录是否存在
        /// </summary>
        /// <param name="RemoteDirectoryName">指定的目录名</param>
        public bool DirectoryExist(string RemoteDirectoryName)
        {
            string[] dirList = GetDirectoryList();
            foreach (string str in dirList)
            {
                if (str.Trim() == RemoteDirectoryName.Trim())
                {
                    return true;
                }
            }
            return false;
        }
        /// <summary>
        /// 判断当前目录下指定的文件是否存在
        /// </summary>
        /// <param name="RemoteFileName">远程文件名</param>
        public bool FileExist(string RemoteFileName)
        {
            string[] fileList = GetFileList("*.*");
            foreach (string str in fileList)
            {
                if (str.Trim() == RemoteFileName.Trim())
                {
                    return true;
                }
            }
            return false;
        }
        /// <summary>
        /// 创建文件夹
        /// </summary>
        /// <param name="dirName"></param>
        public void MakeDir(string dirName)
        {
            FtpWebRequest reqFTP;
            try
            {
                // dirName = name of the directory to create.
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + dirName));
                reqFTP.Method = WebRequestMethods.Ftp.MakeDirectory;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                ftpStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "MakeDir Error --> " + ex.Message);
            }
        }
        /// <summary>
        /// 获取指定文件大小
        /// </summary>
        /// <param name="filename"></param>
        /// <returns></returns>
        public long GetFileSize(string filename)
        {
            FtpWebRequest reqFTP;
            long fileSize = ;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + filename));
                reqFTP.Method = WebRequestMethods.Ftp.GetFileSize;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                fileSize = response.ContentLength;
                ftpStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "GetFileSize Error --> " + ex.Message);
            }
            return fileSize;
        }
        /// <summary>
        /// 改名
        /// </summary>
        /// <param name="currentFilename"></param>
        /// <param name="newFilename"></param>
        public void ReName(string currentFilename, string newFilename)
        {
            FtpWebRequest reqFTP;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + currentFilename));
                reqFTP.Method = WebRequestMethods.Ftp.Rename;
                reqFTP.RenameTo = newFilename;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();
                ftpStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                Insert_Standard_ErrorLog.Insert("FtpWeb", "ReName Error --> " + ex.Message);
            }
        }
        /// <summary>
        /// 移动文件
        /// </summary>
        /// <param name="currentFilename"></param>
        /// <param name="newFilename"></param>
        public void MovieFile(string currentFilename, string newDirectory)
        {
            ReName(currentFilename, newDirectory);
        }
        /// <summary>
        /// 切换当前目录
        /// </summary>
        /// <param name="DirectoryName"></param>
        /// <param name="IsRoot">true 绝对路径   false 相对路径</param>
        public void GotoDirectory(string DirectoryName, bool IsRoot)
        {
            if (IsRoot)
            {
                ftpRemotePath = DirectoryName;
            }
            else
            {
                ftpRemotePath += DirectoryName + "/";
            }
            ftpURI = "ftp://" + ftpServerIP + "/" + ftpRemotePath + "/";
        }
    }
 

http://blog.csdn.net/gavin_luo/article/details/3906779