【转载】C#工具类：FTP操作辅助类FTPHelper

FTP是一个8位的客户端-服务器协议，能操作任何类型的文件而不需要进一步处理，就像MIME或Unicode一样。可以通过C#中的FtpWebRequest类、NetworkCredential类、WebRequestMethods类来实现一个FTP操作的相关辅助类FTPHelper。

先来看MSDN关于上述几个类的定义以及解释：

FtpWebRequest类：实现文件传输协议 (FTP) 客户端。若要获取的实例FtpWebRequest，使用Create方法。 此外可以使用WebClient类来上传和下载信息从 FTP 服务器。 使用任一种方法，当您指定使用 FTP 方案的网络资源 (例如， "ftp://contoso.com")FtpWebRequest类提供了能够以编程方式与 FTP 服务器进行交互。

NetworkCredential类：为基于密码的身份验证方案（如基本、摘要式、NTLM 和 Kerberos 身份验证）提供凭据。

WebRequestMethods类：WebRequestMethods.Ftp、WebRequestMethods.File 和 WebRequestMethods.Http 类的容器类。 无法继承此类。

封装好的FTPHelper帮助类如下，包含连接FTP服务器、上传文件到FTP服务器、下载FTP服务器文件、删除FTP服务器文件、获取当前目录下明细等几个常用方法。具体实现如下：

 public class FTPHelper
    {
        #region 字段
        string ftpURI;
        string ftpUserID;
        string ftpServerIP;
        string ftpPassword;
        string ftpRemotePath;
        #endregion
        /// <summary>
        /// 连接FTP服务器
        /// </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 FTPHelper(string FtpServerIP, string FtpRemotePath, string FtpUserID, string FtpPassword)
        {
            ftpServerIP = FtpServerIP;
            ftpRemotePath = FtpRemotePath;
            ftpUserID = FtpUserID;
            ftpPassword = FtpPassword;
            ftpURI = "ftp://" + ftpServerIP + "/" + ftpRemotePath + "/";
        }
        /// <summary>
        /// 上传
        /// </summary>
        public void Upload(string filename)
        {
            FileInfo fileInf = new FileInfo(filename);
            FtpWebRequest reqFTP;
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileInf.Name));
            reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
            reqFTP.KeepAlive = false;
            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)
            {
                throw new Exception(ex.Message);
            }
        }
        /// <summary>
        /// 下载
        /// </summary>
        public void Download(string filePath, string fileName)
        {
            try
            {
                FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);
                FtpWebRequest reqFTP;
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
                reqFTP.UseBinary = true;
                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)
            {
                throw new Exception(ex.Message);
            }
        }
        /// <summary>
        /// 删除文件
        /// </summary>
        public void Delete(string fileName)
        {
            try
            {
                FtpWebRequest reqFTP;
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + fileName));
                reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
                reqFTP.Method = WebRequestMethods.Ftp.DeleteFile;
                reqFTP.KeepAlive = false;
                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)
            {
                throw new Exception(ex.Message);
            }
        }
        /// <summary>
        /// 获取当前目录下明细(包含文件和文件夹)
        /// </summary>
        public string[] GetFilesDetailList()
        {
            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)
            {
                throw new Exception(ex.Message);
            }
        }
        /// <summary>
        /// 获取FTP文件列表(包括文件夹)
        /// </summary>
        private string[] GetAllList(string url)
        {
            List<string> list = new List<string>();
            FtpWebRequest req = (FtpWebRequest)WebRequest.Create(new Uri(url));
            req.Credentials = new NetworkCredential(ftpPassword, ftpPassword);
            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>
        public string[] GetFileList(string url)
        {
            StringBuilder result = new StringBuilder();
            FtpWebRequest reqFTP;
            try
            {
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(url));
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpPassword, ftpPassword);
                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>
        public void MakeDir(string dirName)
        {
            FtpWebRequest reqFTP;
            try
            {
                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)
            { }
        }
        /// <summary>
        /// 获取指定文件大小
        /// </summary>
        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)
            { }
            return fileSize;
        }
        /// <summary>
        /// 更改文件名
        /// </summary>
        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)
            { }
        }
        /// <summary>
        /// 移动文件
        /// </summary>
        public void MovieFile(string currentFilename, string newDirectory)
        {
            ReName(currentFilename, newDirectory);
        }
        /// <summary>
        /// 切换当前目录
        /// </summary>
        /// <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 + "/";
        }
    }

备注：此文章转载自C#工具类：FTP操作辅助类FTPHelper_IT技术小趣屋。

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