c# ftp读取下载

/// <summary>
    /// ftp辅助类
    /// </summary>
    public class ftpHelper
    {
        #region
        /// <summary>
        /// FTP获取文件列表
        /// </summary>
        /// <param name="ftpServerIP"></param>
        /// <param name="ftpUserID"></param>
        /// <param name="ftpPassword"></param>
        /// <returns></returns>
        public static string[] FTPGetFileList(string ftpServerIP, string ftpUserID, string ftpPassword)
        {
            //响应结果
            StringBuilder result = new StringBuilder();

            //FTP请求
            FtpWebRequest ftpRequest = null;

            //FTP响应
            WebResponse ftpResponse = null;

            //FTP响应流
            StreamReader ftpResponsStream = null;

            try
            {
                //生成FTP请求
                ftpRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/"));

                //设置文件传输类型
                ftpRequest.UseBinary = true;

                //FTP登录
                ftpRequest.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

                //设置FTP方法
                ftpRequest.Method = WebRequestMethods.Ftp.ListDirectory;

                //生成FTP响应
                ftpResponse = ftpRequest.GetResponse();

                //FTP响应流
                ftpResponsStream = new StreamReader(ftpResponse.GetResponseStream());

                string line = ftpResponsStream.ReadLine();

                while (line != null)
                {
                    result.Append(line);
                    result.Append("\n");
                    line = ftpResponsStream.ReadLine();
                }

                //去掉结果列表中最后一个换行
                result.Remove(result.ToString().LastIndexOf('\n'), 1);

                //返回结果
                return result.ToString().Split('\n');
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return (null);
            }
            finally
            {
                if (ftpResponsStream != null)
                {
                    ftpResponsStream.Close();
                }

                if (ftpResponse != null)
                {
                    ftpResponse.Close();
                }
            }
        }

        #endregion

        #region FTP下载文件

        /// <summary>
        /// FTP下载文件
        /// </summary>
        /// <param name="ftpServerIP">FTP服务器IP</param>
        /// <param name="ftpUserID">FTP登录帐号</param>
        /// <param name="ftpPassword">FTP登录密码</param>
        /// <param name="saveFilePath">保存文件路径</param>
        /// <param name="saveFileName">保存文件名</param>
        /// <param name="downloadFileName">下载文件名</param>
        public static void FTPDownloadFile(string ftpServerIP, string ftpUserID, string ftpPassword,
            string saveFilePath, string saveFileName, string downloadFileName)
        {
            //定义FTP请求对象
            FtpWebRequest ftpRequest = null;
            //定义FTP响应对象
            FtpWebResponse ftpResponse = null;

            //存储流
            FileStream saveStream = null;
            //FTP数据流
            Stream ftpStream = null;

            try
            {
                //生成下载文件
                saveStream = new FileStream(saveFilePath + "\\" + saveFileName, FileMode.Create);

                //生成FTP请求对象
                ftpRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + downloadFileName));

                //设置下载文件方法
                ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;

                //设置文件传输类型
                ftpRequest.UseBinary = true;

                //设置登录FTP帐号和密码
                ftpRequest.Credentials = new NetworkCredential(ftpUserID, ftpPassword);

                //生成FTP响应对象
                ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();

                //获取FTP响应流对象
                ftpStream = ftpResponse.GetResponseStream();

                //响应数据长度
                long cl = ftpResponse.ContentLength;

                int bufferSize = 2048;

                int readCount;

                byte[] buffer = new byte[bufferSize];

                //接收FTP文件流
                readCount = ftpStream.Read(buffer, 0, bufferSize);

                while (readCount > 0)
                {
                    saveStream.Write(buffer, 0, readCount);

                    readCount = ftpStream.Read(buffer, 0, bufferSize);
                }

            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
            finally
            {
                if (ftpStream != null)
                {
                    ftpStream.Close();
                }
               
                if (saveStream != null)
                {
                    saveStream.Close();
                }

                if (ftpResponse != null)
                {
                    ftpResponse.Close();
                }
            }
        }

        #endregion
    }