public class FtpWeb
{
    string ftpRemotePath;
    string ftpUserID;
    string ftpPassword;
    string ftpURI;
    string ftpServerIP;
     
    /// 

    /// 连接FTP
    /// 
    /// FTP连接地址
    /// 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
    /// 用户名
    /// 密码
    public FtpWeb(string FtpServerIP, string FtpUserID, string FtpPassword)
    {
        ftpServerIP = FtpServerIP;
        ftpUserID = FtpUserID;
        ftpPassword = FtpPassword;
        ftpURI = FtpServerIP + "/";
    }
     
    /// 

    /// 上传
    /// 
    /// 
    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 = 2048;
        byte[] buff = new byte[buffLength];
        int contentLen;
        FileStream fs = fileInf.OpenRead();
        try
        {
            Stream strm = reqFTP.GetRequestStream();
            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)
        {
            throw ex;
        }
    }
    /// 

    /// 上传
    /// 
    /// 
    public void Upload2(string ftpuri, string filename)
    {
        FileInfo fileInf = new FileInfo(filename);
        string uri = ftpuri;
        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 = 2048;
        byte[] buff = new byte[buffLength];
        int contentLen;
        FileStream fs = fileInf.OpenRead();
        try
        {
            Stream strm = reqFTP.GetRequestStream();
            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)
        {
            throw ex;
        }
    }
    /// 

    /// 下载
    /// 
    /// 
    /// 
    public void Download(string filePath, string ftpUri, string fileName)
    {
        FtpWebRequest reqFTP;
        try
        {
            FileStream outputStream = new FileStream(filePath + "\\" + fileName, FileMode.Create);
     
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpUri));
            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 = 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)
        {
            throw ex;
        }
    }
     
     
    /// 

    /// 删除文件
    /// 
    /// 
    public void Delete(string fileName)
    {
        try
        {
            string uri = 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)
        {
            throw ex;
        }
    }
     
    /// 

    /// 删除文件夹
    /// 
    /// 
    public void RemoveDirectory(string folderName)
    {
        try
        {
            string uri = ftpURI + folderName;
            FtpWebRequest reqFTP;
            reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
     
            reqFTP.Credentials = new NetworkCredential(ftpUserID, 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)
        {
            throw ex;
        }
    }
     
    /// 

    /// 获取当前目录下明细(包含文件和文件夹)
    /// 
    /// 
    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(), 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;
            throw ex;
        }
    }
     
    /// 

    /// 获取当前目录下文件列表(仅文件)
    /// 
    /// 
    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(ftpUserID, 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;
            throw ex;
        }
    }
     
    /// 

    /// 获取当前目录下所有的文件夹列表(仅文件夹)
    /// 
    /// 
    public string[] GetDirectoryList()
    {
        string[] drectory = GetFilesDetailList();
        string m = string.Empty;
        foreach (string str in drectory)
        {
            int dirPos = str.IndexOf("");
            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(54).Trim();
                if (dir != "." && dir != "..")
                {
                    m += dir + "\n";
                }
            }
        }
     
        char[] n = new char[] { '\n' };
        return m.Split(n);
    }
     
    /// 

    /// 判断当前目录下指定的子目录是否存在
    /// 
    /// 指定的目录名
    public bool DirectoryExist(string RemoteDirectoryName)
    {
        try
        {
            string[] dirList = GetDirectoryList();
     
            foreach (string str in dirList)
            {
                if (str.Trim() == RemoteDirectoryName.Trim())
                {
                    return true;
                }
            }
            return false;
        }
        catch
        {
            return false;
        }
     
    }
     
    /// 

    /// 判断当前目录下指定的文件是否存在
    /// 
    /// 远程文件名
    public bool FileExist(string RemoteFileName)
    {
        string[] fileList = GetFileList("*.*");
        foreach (string str in fileList)
        {
            if (str.Trim() == RemoteFileName.Trim())
            {
                return true;
            }
        }
        return false;
    }
     
    /// 

    /// 创建文件夹
    /// 
    /// 
    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)
        {
            throw ex;
        }
    }
     
    /// 

    /// 获取指定文件大小
    /// 
    /// 
    /// 
    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(ftpUserID, ftpPassword);
            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
            Stream ftpStream = response.GetResponseStream();
            fileSize = response.ContentLength;
     
            ftpStream.Close();
            response.Close();
        }
        catch (Exception ex)
        {
            throw ex;
        }
        return fileSize;
    }
     
    /// 

    /// 改名
    /// 
    /// 
    /// 
    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)
        {
            throw ex;
        }
    }
     
    /// 

    /// 移动文件
    /// 
    /// 
    /// 
    public void MovieFile(string currentFilename, string newDirectory)
    {
        ReName(currentFilename, newDirectory);
    }
     
    /// 

    /// 切换当前目录
    /// 
    /// 
    /// true 绝对路径   false 相对路径
    public void GotoDirectory(string DirectoryName, bool IsRoot)
    {
        if (IsRoot)
        {
            ftpRemotePath = DirectoryName;
        }
        else
        {
            ftpRemotePath += DirectoryName + "/";
        }
        ftpURI = "ftp://" + ftpServerIP + "/" + ftpRemotePath + "/";
    }
}

网站题目：C#FTP操作类
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