前言

文件传输协议（File Transfer Protocol，FTP）是用于在网络上进行文件传输的一套标准协议，它工作在 OSI 模型的第七层， TCP 模型的第四层， 即应用层， 使用 TCP 传输而不是 UDP， 客户在和服务器建立连接前要经过一个“三次握手”的过程， 保证客户与服务器之间的连接是可靠的， 而且是面向连接， 为数据传输提供可靠保证。

FTP允许用户以文件操作的方式（如文件的增、删、改、查、传送等）与另一主机相互通信。然而， 用户并不真正登录到自己想要存取的计算机上面而成为完全用户， 可用FTP程序访问远程资源， 实现用户往返传输文件、目录管理以及访问电子邮件等等， 即使双方计算机可能配有不同的操作系统和文件存储方式。

一、FTP的花样操作

1.配置文件

public class FTPConfig
{
    /// <summary>
    /// 
    /// </summary>
    public FTPConfig()
    {
        IsUpload = false;
        FtpServerIP = "127.0.0.1";
        FtpRemotePath = "";
        FtpUserID = "ftpTest";
        FtpPassword = "a123456.";
    }

    /// <summary>
    /// 是否上传
    /// </summary>
    public bool IsUpload { get; set; }

    /// <summary>
    /// FTP的IP地址
    /// </summary>
    public string FtpServerIP { get; set; }

    /// <summary>
    /// 上传FTP目录
    /// </summary>
    public string FtpRemotePath { get; set; }

    /// <summary>
    /// 用户名
    /// </summary>
    public string FtpUserID { get; set; }

    /// <summary>
    /// 密码
    /// </summary>
    public string FtpPassword { get; set; }
}

2.FTP的操作封装类

public class FTPHelp
{
    private string ftpURI;
    private FTPConfig ftpConfig { get; set; }

    /// <summary>
    ///  连接FTP
    /// </summary>
    /// <param name="ftpConfig"></param>
    public FTPHelp(FTPConfig ftpConfig)
    {
        this.ftpConfig = ftpConfig;
        if (string.IsNullOrEmpty(this.ftpConfig.FtpRemotePath))
        {
            ftpURI = "ftp://" + this.ftpConfig.FtpServerIP + "/";
        }
        else
        {
            ftpURI = "ftp://" + this.ftpConfig.FtpServerIP + "/" + this.ftpConfig.FtpRemotePath + "/";
        }
    }
    
    /// <summary>
    /// 上传
    /// </summary>
    /// <param name="filename"></param>
    public void Upload(string filename)
    {
        if (ftpConfig.IsUpload)
        {
            FileInfo fileInfo = new FileInfo(filename);
            string uri = ftpURI + fileInfo.Name;
            FtpWebRequest reqFTP;

            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
            reqFTP.Credentials = new NetworkCredential(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            reqFTP.KeepAlive = false;
            reqFTP.Method = WebRequestMethods.Ftp.UploadFile;
            reqFTP.UseBinary = true;
            reqFTP.ContentLength = fileInfo.Length;

            int buffLength = 2048;
            byte[] buff = new byte[buffLength];
            int contentLen;
            using (FileStream fs = fileInfo.OpenRead())
            {
                using (Stream strm = reqFTP.GetRequestStream())
                {
                    try
                    {
                        contentLen = fs.Read(buff, 0, buffLength);
                        while (contentLen != 0)
                        {
                            strm.Write(buff, 0, contentLen);
                            contentLen = fs.Read(buff, 0, buffLength);
                        }
                        strm.Close();
                        fs.Close();
                    }
                    catch (Exception ex)
                    {
                        string errorMessage = "Upload Error --> " + ex.Message;
                        //logger.Error(errorMessage);
                        throw;
                    }
                }
            }
        }
        else
        {
            //logger.Debug("[UploadData] uploadConfig.IsUpload is false,abort to loaddata");
        }
    }

    /// <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(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
            Stream ftpStream = response.GetResponseStream();
            long cl = response.ContentLength;
            int bufferSize = 2048;
            int readCount;
            byte[] buffer = new byte[bufferSize];

            readCount = ftpStream.Read(buffer, 0, bufferSize);
            while (readCount > 0)
            {
                outputStream.Write(buffer, 0, readCount);
                readCount = ftpStream.Read(buffer, 0, bufferSize);
            }

            ftpStream.Close();
            outputStream.Close();
            response.Close();
        }
        catch (Exception ex)
        {
            string errorMessage = "Download Error --> " + ex.Message;
            //logger.Error(errorMessage);
            throw;
        }
    }

    /// <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(ftpConfig.FtpUserID, ftpConfig.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)
        {
            string errorMessage = "Delete Error --> " + ex.Message + "  文件名:" + fileName;
            //logger.Error(errorMessage);
            throw;
        }
    }

    /// <summary>
    /// 删除文件夹
    /// </summary>
    /// <param name="folderName"></param>
    public void RemoveDirectory(string folderName)
    {
        try
        {
            string uri = ftpURI + folderName;
            FtpWebRequest reqFTP;
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));

            reqFTP.Credentials = new NetworkCredential(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            reqFTP.KeepAlive = false;
            reqFTP.Method = WebRequestMethods.Ftp.RemoveDirectory;

            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)
        {
            string errorMessage = "Delete Error --> " + ex.Message + "  文件名:" + folderName;
            //logger.Error(errorMessage);
            throw;
        }
    }

    /// <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(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            ftp.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
            WebResponse response = ftp.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default);

            string line = reader.ReadLine();

            while (line != null)
            {
                result.Append(line);
                result.Append("\n");
                line = reader.ReadLine();
            }
            result.Remove(result.ToString().LastIndexOf("\n"), 1);
            reader.Close();
            response.Close();
            return result.ToString().Split('\n');
        }
        catch (Exception ex)
        {
            downloadFiles = null;
            //logger.Error(ex);
            return downloadFiles;
        }
    }

    /// <summary>
    /// 获取当前目录下文件列表(仅文件)
    /// </summary>
    /// <returns></returns>
    public string[] GetFileList(string mask)
    {
        string[] downloadFiles;
        StringBuilder result = new StringBuilder();
        FtpWebRequest reqFTP;
        try
        {
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI));
            reqFTP.UseBinary = true;
            reqFTP.Credentials = new NetworkCredential(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            reqFTP.Method = WebRequestMethods.Ftp.ListDirectory;
            WebResponse response = reqFTP.GetResponse();
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.Default);

            string line = reader.ReadLine();
            while (line != null)
            {
                if (mask.Trim() != string.Empty && mask.Trim() != "*.*")
                {
                    string mask_ = mask.Substring(0, mask.IndexOf("*"));
                    if (line.Substring(0, mask_.Length) == mask_)
                    {
                        result.Append(line);
                        result.Append("\n");
                    }
                }
                else
                {
                    result.Append(line);
                    result.Append("\n");
                }
                line = reader.ReadLine();
            }
            result.Remove(result.ToString().LastIndexOf('\n'), 1);
            reader.Close();
            response.Close();
            return result.ToString().Split('\n');
        }
        catch (Exception ex)
        {
            downloadFiles = null;
            if (ex.Message.Trim() != "远程服务器返回错误: (550) 文件不可用(例如，未找到文件，无法访问文件)。")
            {
                string errorMessage = "GetFileList Error --> " + ex.Message.ToString();
                //logger.Error(errorMessage);
            }
            return downloadFiles;
        }
    }

    /// <summary>
    /// 获取当前目录下所有的文件夹列表(仅文件夹)
    /// </summary>
    /// <returns></returns>
    public string[] GetDirectoryList()
    {
        string[] drectory = GetFilesDetailList();
        string m = string.Empty;
        foreach (string str in drectory)
        {
            int dirPos = str.IndexOf("<DIR>");
            if (dirPos > 0)
            {
                /*判断 Windows 风格*/
                m += str.Substring(dirPos + 5).Trim() + "\n";
            }
            else if (str.Trim().Substring(0, 1).ToUpper() == "D")
            {
                /*判断 Unix 风格*/
                string dir = str.Substring(49).Trim();
                if (dir != "." && dir != "..")
                {
                    m += dir + "\n";
                }
            }
        }

        char[] n = new char[] { '\n' };
        return m.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()
    {
        if (!string.IsNullOrEmpty(ftpConfig.FtpRemotePath))
        {
            FtpWebRequest reqFTP;
            try
            {
                // dirName = name of the directory to create.
                reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI));
                reqFTP.Method = WebRequestMethods.Ftp.MakeDirectory;
                reqFTP.UseBinary = true;
                reqFTP.Credentials = new NetworkCredential(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
                FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
                Stream ftpStream = response.GetResponseStream();

                ftpStream.Close();
                response.Close();
            }
            catch (Exception ex)
            {
                string errorMesasge = "MakeDir Error --> " + ex.Message;
                //logger.Error(errorMesasge);
                throw;
            }
        }
    }

    /// <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 = 0;
        try
        {
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpURI + filename));
            reqFTP.Method = WebRequestMethods.Ftp.GetFileSize;
            reqFTP.UseBinary = true;
            reqFTP.Credentials = new NetworkCredential(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
            Stream ftpStream = response.GetResponseStream();
            fileSize = response.ContentLength;

            ftpStream.Close();
            response.Close();
        }
        catch (Exception ex)
        {
            string errorMesasge = "GetFileSize Error --> " + ex.Message;
            //logger.Error(errorMesasge);
            throw;
        }
        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(ftpConfig.FtpUserID, ftpConfig.FtpPassword);
            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
            Stream ftpStream = response.GetResponseStream();

            ftpStream.Close();
            response.Close();
        }
        catch (Exception ex)
        {
            string errorMesasge = "ReName Error --> " + ex.Message;
            //logger.Error(errorMesasge);
            throw;
        }
    }

    /// <summary>
    /// 移动文件
    /// </summary>
    /// <param name="currentFilename"></param>
    /// <param name="newDirectory"></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)
        {
            ftpConfig.FtpRemotePath = DirectoryName;
        }
        else
        {
            ftpConfig.FtpRemotePath += DirectoryName + "/";
        }
        ftpURI = "ftp://" + ftpConfig.FtpServerIP + "/" + ftpConfig.FtpRemotePath + "/";
    }

    /// <summary>
    /// 删除订单目录
    /// </summary>
    /// <param name="ftpConfig"></param>
    /// <param name="folderToDelete"></param>
    public static void DeleteOrderDirectory(FTPConfig ftpConfig, string folderToDelete)
    {
        try
        {
            if (!string.IsNullOrEmpty(ftpConfig.FtpServerIP) &&
                !string.IsNullOrEmpty(folderToDelete) &&
                !string.IsNullOrEmpty(ftpConfig.FtpUserID) &&
                !string.IsNullOrEmpty(ftpConfig.FtpPassword))
            {
                FTPTestViewModel fw = new FTPTestViewModel(ftpConfig);
                //进入订单目录
                fw.GotoDirectory(folderToDelete, true);
                //获取规格目录
                string[] folders = fw.GetDirectoryList();
                foreach (string folder in folders)
                {
                    if (!string.IsNullOrEmpty(folder) || folder != "")
                    {
                        //进入订单目录
                        string subFolder = folderToDelete + "/" + folder;
                        fw.GotoDirectory(subFolder, true);
                        //获取文件列表
                        string[] files = fw.GetFileList("*.*");
                        if (files != null)
                        {
                            //删除文件
                            foreach (string file in files)
                            {
                                fw.Delete(file);
                            }
                        }
                        //删除冲印规格文件夹
                        fw.GotoDirectory(folderToDelete, true);
                        fw.RemoveDirectory(folder);
                    }
                }

                //删除订单文件夹
                string parentFolder = folderToDelete.Remove(folderToDelete.LastIndexOf('/'));
                string orderFolder = folderToDelete.Substring(folderToDelete.LastIndexOf('/') + 1);
                fw.GotoDirectory(parentFolder, true);
                fw.RemoveDirectory(orderFolder);
            }
            else
            {
                throw new Exception("FTP 及路径不能为空！");
            }
        }
        catch (Exception ex)
        {
            throw new Exception("删除订单时发生错误，错误信息为：" + ex.Message);
        }
    }
}

3.使用

public void Upload()
{
    ftpConfig.IsUpload = true;
    Upload(@"D:\temp.png");
    MessageBox.Show("上传完成!!!");
}

public void Download()
{
    Download(@"D:\", "temp.png");
    MessageBox.Show("下载完成!!!");
}

public void Delete()
{
    Delete("temp.png");
    MessageBox.Show("删除完成!!!");
}