C# FTP简单帮助类

最近做的项目需要用到FTP传输文件，所以写这么一个帮助类，功能比较简单，可以实现基本的上传和下载，包括递归下载文件夹，代码如下：

public class FtpAccess : IDisposable
{
    #region 私有变量
    /// <summary>
    /// Ftp请求对象
    /// </summary>
    private FtpWebRequest _request = null;

    /// <summary>
    /// Ftp响应对象
    /// </summary>
    private FtpWebResponse _response = null;

    /// <summary>
    /// 是否需要删除临时文件
    /// </summary>
    private bool _isDeleteTempFile = false;

    /// <summary>
    /// 异步上传时临时生成的文件
    /// </summary>
    private string _uploadTempFile = "";

    #endregion

    #region 公共属性

    ///<summary>
    /// Ftp服务器地址:wifi.ttoocc.com/
    /// </summary>
    public string ServerUri { get; set; }

    /// <summary>
    /// Ftp服务器登录用户
    /// </summary>
    public string UserName { get; set; }

    /// <summary>
    /// Ftp服务器登录密码
    /// </summary>
    public string Password { get; set; }

    #endregion

    #region 构造函数
    public FtpAccess() { }
    /// <summary>
    /// 实例化FTP帮助类
    /// </summary>
    /// <param name="serverUri">FTP服务器地址（IP或域名）</param>
    /// <param name="userName">FTP用户名</param>
    /// <param name="password">FTP密码</param>
    public FtpAccess(string serverUri, string userName, string password)
    {
        ServerUri = serverUri;
        UserName = userName;
        Password = password;
    }
    #endregion

    #region 实现接口
    public void Dispose()
    {
        if (_request != null)
        {
            _request.Abort();
            _request = null;
        }
        if (_response != null)
        {
            _response.Close();
            _response = null;
        }
    }
    #endregion

    #region 事件
    /// <summary>
    /// 上传文件
    /// </summary>
    /// <param name="fileLocalPath">需要上传的文件</param>
    /// <param name="remoteDir">目标路径</param>
    /// <param name="newFileName">新的文件名</param>
    public bool UploadFile(string fileLocalPath, string remoteDir, string newFileName)
    {
        FileInfo file = new FileInfo(fileLocalPath);
        if (remoteDir.Trim() == "")
        {
            return false;
        }
        string URI = "FTP://" + ServerUri + "/" + remoteDir + "/" + newFileName;
        _request = null;
        if (!FtpIsExistsDir(remoteDir))
        {
            CreateDir(remoteDir);
        }
        if (FtpIsExistsFile(remoteDir + "/" + newFileName))
        {
            _request = GetRequest(URI);
            _request.KeepAlive = false;
            _request.Method = System.Net.WebRequestMethods.Ftp.DeleteFile; //删除
            _request.GetResponse();
        }
        //URI = "FTP://" + hostname + "/" + targetDir + "/" + newFileName;
        _request = null;
        _request = GetRequest(URI);
        _request.UseBinary = true;
        _request.UsePassive = true;
        _request.KeepAlive = false;
        _request.Method = System.Net.WebRequestMethods.Ftp.UploadFile;
        //指定文件传输的数据类型

        //告诉ftp文件大小
        _request.ContentLength = file.Length;
        //缓冲大小设置为2KB
        int BufferSize = 2048, lastBufferSize, count;
        //计算包个数
        count = (int)file.Length / BufferSize + 1;
        //计算最后一个包大小
        lastBufferSize = (int)file.Length % BufferSize;
        byte[] content = new byte[BufferSize];
        int dataRead;
        //打开一个文件流 (System.IO.FileStream) 去读上传的文件
        using (FileStream fs = file.OpenRead())
        {
            try
            {
                //把上传的文件写入流
                using (Stream rs = _request.GetRequestStream())
                {
                    while (count > 1)
                    {
                        dataRead = fs.Read(content, 0, BufferSize);
                        rs.Write(content, 0, BufferSize);
                        count--;
                    }
                    content = new byte[lastBufferSize];
                    dataRead = fs.Read(content, 0, lastBufferSize);
                    rs.Write(content, 0, lastBufferSize);
                    rs.Close();
                    rs.Dispose();
                    fs.Close();
                    fs.Dispose();
                    return true;
                }
            }
            catch (Exception)
            {
                return false;
            }
            finally
            {
                fs.Close();
                fs.Dispose();
            }
        }

    }

    /// <summary>
    /// 下载文件
    /// </summary>
    /// <param name="localDir">下载至本地路径</param>
    /// <param name="ftpDir">ftp目标文件路径</param>
    /// <param name="ftpFile">从ftp要下载的文件名</param>
    public void DownloadFile(string localDir, string ftpDir, string ftpFile)
    {
        string URI = "FTP://" + ServerUri + "/" + ftpDir + "/" + ftpFile;
        string tmpname = Guid.NewGuid().ToString();
        string localfile = localDir + @"\" + tmpname;
        if (!Directory.Exists(localDir))
            Directory.CreateDirectory(localDir);
        _request = GetRequest(URI);
        _request.Method = System.Net.WebRequestMethods.Ftp.DownloadFile;
        _request.UseBinary = true;
        _request.UsePassive = false;
        using (FtpWebResponse response = (FtpWebResponse)_request.GetResponse())
        {
            using (Stream responseStream = response.GetResponseStream())
            {
                using (FileStream fs = new FileStream(localfile, FileMode.CreateNew))
                {
                    try
                    {
                        byte[] buffer = new byte[2048];
                        int read = 0;
                        do
                        {
                            read = responseStream.Read(buffer, 0, buffer.Length);
                            fs.Write(buffer, 0, read);
                        } while (read != 0);
                        responseStream.Close();
                        fs.Flush();
                        fs.Close();
                    }
                    catch (Exception)
                    {
                        fs.Close();
                        File.Delete(localfile);
                        throw;
                    }
                }
                responseStream.Close();
            }
            response.Close();
        }

        try
        {
            File.Delete(localDir + @"\" + ftpFile);
            File.Move(localfile, localDir + @"\" + ftpFile);
        }
        catch (Exception ex)
        {
            File.Delete(localfile);
            throw ex;
        }
        _request = null;
    }
    /// <summary>
    /// 从FTP上下载文件夹及其内容（递归）
    /// </summary>
    /// <param name="localDir"></param>
    /// <param name="ftpDir"></param>
    /// <returns></returns>
    public bool DownloadDirectory(string localDir, string ftpDir)
    {
        var list = GetDirectoriesListInfo(ftpDir);
        foreach (var item in list)
        {
            if (item.Groups[1].Value == "d")
            {
                DownloadDirectory(localDir + @"\" + item.Groups[6].Value, ftpDir + "/" + item.Groups[6].Value);
            }
            else
            {
                var file = new FileInfo(localDir + @"\" + item.Groups[6].Value);
                if (file.Exists)
                {
                    var ftpDateTime = GetLastModified(ftpDir + @"\" + item.Groups[6].Value);
                    var localDataTime = file.LastWriteTime;
                    if (ftpDateTime <= localDataTime)//若本地文件比FTP文件新，则不用下载该文件
                        continue;
                }
                DownloadFile(localDir, ftpDir, item.Groups[6].Value);
            }
        }
        return true;
    }
    /// <summary>
    /// 搜索远程文件
    /// </summary>
    /// <param name="targetDir">远程文件夹(不能以"/"结尾) e.q. "aaa/bbb/ccc"</param>
    /// <returns></returns>
    public List<string> GetDirectoriesList(string targetDir)
    {
        var lastDirName = targetDir.Substring(targetDir.LastIndexOf(&#39;/&#39;) + 1);
        List<string> result = new List<string>();
        try
        {
            string URI = "FTP://" + ServerUri + "/" + targetDir;
            _request = GetRequest(URI);
            _request.Method = System.Net.WebRequestMethods.Ftp.ListDirectory;
            _request.UsePassive = true;
            _request.UseBinary = true;

            string str = GetStringResponse(_request);
            str = str.Replace(lastDirName + "/", null);
            if (str != string.Empty)
                result.AddRange(str.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
            return result;
        }
        catch { return null; }
    }
    public List<string> GetDirectoriesList(string targetDir, string searchKey)
    {
        var lastDirName = targetDir.Substring(targetDir.LastIndexOf(&#39;/&#39;) + 1);
        List<string> result = new List<string>();
        try
        {
            string URI = "FTP://" + ServerUri + "/" + targetDir;
            _request = GetRequest(URI);
            _request.Method = System.Net.WebRequestMethods.Ftp.ListDirectory;
            _request.UsePassive = true;
            _request.UseBinary = true;

            string str = GetStringResponse(_request);
            str = str.Replace(lastDirName + "/", null);
            if (str != string.Empty)
                result.AddRange(str.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
            return result.Where(m => m.Contains(searchKey)).ToList();
        }
        catch { return null; }
    }
    /// <summary>
    /// 获取FTP指定目录下文件及文件夹列表
    /// </summary>
    /// <param name="targetDir"></param>
    /// <returns></returns>
    public List<Match> GetDirectoriesListInfo(string targetDir)
    {
        var lastDirName = targetDir.Substring(targetDir.LastIndexOf(&#39;/&#39;) + 1);
        List<Match> result = new List<Match>();
        try
        {
            string URI = "FTP://" + ServerUri + "/" + targetDir;
            _request = GetRequest(URI);
            _request.Method = System.Net.WebRequestMethods.Ftp.ListDirectoryDetails;
            _request.UsePassive = true;
            _request.UseBinary = true;

            string str = GetStringResponse(_request);
            List<string> strs = new List<string>();
            if (str != string.Empty)
                strs.AddRange(str.Split(new string[] { Environment.NewLine }, StringSplitOptions.RemoveEmptyEntries));
            Regex regex = new Regex(@"^([d-])([rwxt-]{3}){3}\s+\d{1,}\s+.*?(\d{1,})\s+(\w+\s+\d{1,2}\s+(?:\d{4})?)(\d{1,2}:\d{2})?\s+(.+?)\s?$", RegexOptions.Compiled | RegexOptions.Multiline | RegexOptions.IgnoreCase | RegexOptions.IgnorePatternWhitespace);
            foreach (var item in strs)
            {
                Match match = regex.Match(item);
                result.Add(match);
            }
            return result;
        }
        catch { return null; }
    }

    /// <summary>
    /// 获取文件或文件夹的最后修改时间
    /// </summary>
    /// <param name="path">路径</param>
    /// <returns></returns>
    private DateTime GetLastModified(string path)
    {
        try
        {
            string uri = "ftp://" + ServerUri + "/" + path;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.GetDateTimestamp;
            _response = (FtpWebResponse)_request.GetResponse();
            return _response.LastModified;
        }
        catch (Exception)
        {
            return DateTime.MinValue;
        }
    }

    /// <summary>
    /// 在ftp服务器上创建目录
    /// </summary>
    /// <param name="dirName">目录名称</param>
    /// <returns></returns>
    public bool CreateDir(string dirName)
    {
        try
        {
            string uri = "ftp://" + ServerUri + "/" + dirName;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.MakeDirectory;
            _response = (FtpWebResponse)_request.GetResponse();
            _response.Close();
            return true;
        }
        catch (Exception)
        {
            return false;
        }
    }

    /// <summary>
    /// 删除目录
    /// </summary>
    /// <param name="dirName">删除的目录名称</param>
    public bool DelDir(string dirName)
    {
        try
        {
            string uri = "ftp://" + ServerUri + "/" + dirName;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.RemoveDirectory;
            _response = (FtpWebResponse)_request.GetResponse();
            _response.Close();
            return true;
        }
        catch (Exception)
        {
            return false;
        }
    }

    /// <summary>
    /// 文件重命名
    /// </summary>
    /// <param name="currentFilename">当前目录名称</param>
    /// <param name="newFilename">重命名目录名称</param>
    public bool Rename(string currentFilename, string newFilename)
    {
        try
        {
            FileInfo fileInf = new FileInfo(currentFilename);
            string uri = "ftp://" + ServerUri + "/" + fileInf.Name;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.Rename;
            _request.RenameTo = newFilename;
            _response = (FtpWebResponse)_request.GetResponse();
            _response.Close();
            return true;
        }
        catch (Exception)
        {
            return false;
        }
    }

    /// <summary>
    /// 判断ftp服务器上该目录是否存在
    /// </summary>
    /// <param name="dirName"></param>
    /// <param name="ftpHostIP"></param>
    /// <param name="username"></param>
    /// <param name="password"></param>
    /// <returns></returns>
    public bool FtpIsExistsDir(string dirName)
    {
        bool flag = true;
        try
        {
            string uri = "ftp://" + ServerUri + "/" + dirName;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.ListDirectory;
            _response = (FtpWebResponse)_request.GetResponse();
            _response.Close();
        }
        catch (Exception)
        {
            flag = false;
        }
        return flag;
    }

    /// <summary>
    /// 检测文件是否存在
    /// </summary>
    /// <param name="fileFullName"></param>
    /// <param name="ftpHostIP"></param>
    /// <param name="username"></param>
    /// <param name="password"></param>
    /// <returns></returns>
    public bool FtpIsExistsFile(string fileFullName)
    {
        bool flag = true;
        try
        {
            string uri = "ftp://" + ServerUri + "/" + fileFullName;
            _request = GetRequest(uri);
            _request.Method = WebRequestMethods.Ftp.GetFileSize;
            _response = (FtpWebResponse)_request.GetResponse();
            _response.Close();
        }
        catch (Exception)
        {
            flag = false;
        }
        return flag;
    }
    private FtpWebRequest GetRequest(string URI)
    {
        //根据服务器信息FtpWebRequest创建类的对象
        FtpWebRequest result = (FtpWebRequest)FtpWebRequest.Create(URI);
        //提供身份验证信息
        result.Credentials = new System.Net.NetworkCredential(UserName, Password);
        //设置请求完成之后是否保持到FTP服务器的控制连接，默认值为true
        result.KeepAlive = false;
        return result;
    }

    private string GetStringResponse(FtpWebRequest ftp)
    {
        //Get the result, streaming to a string
        string result = "";
        using (FtpWebResponse response = (FtpWebResponse)ftp.GetResponse())
        {
            long size = response.ContentLength;
            using (Stream datastream = response.GetResponseStream())
            {
                using (StreamReader sr = new StreamReader(datastream, System.Text.Encoding.UTF8))
                {
                    result = sr.ReadToEnd();
                    sr.Close();
                }
                datastream.Close();
            }
            response.Close();
        }
        return result;
    }
    #endregion
}