FTP and file handling in C#

In this article I am going to discuss some helpful code snippets in C# to accomplish FTP File operations. I hope this will make your coding easier.

To connect to the FTP server we can use the FtpWebRequest C# object under the System.Net namespace.

Check whether file exists

private bool FtpDirectoryExists(string Directory, string Username, string Password)

        {

            //Directory = "ftp://" + FTPpath + "/" + Selectedfile;

            FtpWebRequest fwr = (FtpWebRequest)WebRequest.Create(Directory);

            FtpWebResponse fRes = default(FtpWebResponse);

            fwr.Credentials = new NetworkCredential(Username, Password);

            fwr.Method = WebRequestMethods.Ftp.GetFileSize;

            try

            {

                fRes = (FtpWebResponse)fwr.GetResponse();

                //no error occured then the file is exists 

                return true;

            }

            catch (WebException ex)

            {

                fRes = (FtpWebResponse)ex.Response;

                //Error occured then the file doesn't exists 

                if (FtpStatusCode.ActionNotTakenFileUnavailable == fRes.StatusCode)

                {

                    return false;

                }

                else

                {

                    //Any other errors you need to handle here 

                    return false;

                }

            }

        }

 Listing all file Names

public DataTable GetFTPFile(string Directory, string Username, string Password)

        {

            DataTable dtFtpFileDetails = new DataTable();

            dtFtpFileDetails.Columns.Add("FileName", typeof(string));

            try

            {

                //Get Directory Details

                FtpWebRequest ftpClientdir;

                ftpClientdir = (FtpWebRequest)FtpWebRequest.Create(Directory);

                ftpClientdir.Credentials = new NetworkCredential(Username, Password);

                ftpClientdir.Method = WebRequestMethods.Ftp.ListDirectoryDetails;

                WebResponse response = ftpClientdir.GetResponse();

                StreamReader reader = new StreamReader(response.GetResponseStream());

                //File names

                FtpWebRequest ftpClient;

                ftpClient = (FtpWebRequest)FtpWebRequest.Create(Directory);

                ftpClient.Credentials = new NetworkCredential(Username, Password);

                ftpClient.Method = WebRequestMethods.Ftp.ListDirectory;

                WebResponse response2 = ftpClient.GetResponse();

                StreamReader reader2 = new StreamReader(response2.GetResponseStream());

                //read file/directory names into arraylist

                string lsdirectory = reader2.ReadLine();

                ArrayList lsnames = new ArrayList();

                while (lsdirectory != null)

                {

                    lsnames.Add(lsdirectory);

                    lsdirectory = reader2.ReadLine();

                }

                //read through directory details response

                string line = reader.ReadLine();

                while (line != null)

                {

                    if (!line.StartsWith("d") && !line.EndsWith(".")) //"d" = dir don't need "." or ".." dirs

                    {

                        foreach (String chk in lsnames) //compare basic dir output to detail dir output to get dir name

                        {

                            if (line.EndsWith(chk))

                            {

                                DataRow dr = dtFtpFileDetails.NewRow();

                                dr["FileName"] = chk;

                                dtFtpFileDetails.Rows.Add(dr);

                            }

                        }

                    }

                    line = reader.ReadLine();

                }

                return dtFtpFileDetails;

            }

            catch (Exception)

            {

                return dtFtpFileDetails;

            }

        }

Download Files

public bool downloadfile(string Directory, string Username, string Password, string Localpath, string filename)

        {

            try

            {

                string localPath = Localpath + "\\";

                FtpWebRequest requestFileDownload = (FtpWebRequest)WebRequest.Create(Directory + "/" + filename);

                requestFileDownload.Credentials = new NetworkCredential(Username, Password);

                requestFileDownload.Method = WebRequestMethods.Ftp.DownloadFile;

                FtpWebResponse responseFileDownload = (FtpWebResponse)requestFileDownload.GetResponse();

                Stream responseStream = responseFileDownload.GetResponseStream();

                FileStream writeStream = new FileStream(localPath + filename, FileMode.Create);

                int Length = 2048;

                Byte[] buffer = new Byte[Length];

                int bytesRead = responseStream.Read(buffer, 0, Length);

                while (bytesRead > 0)

                {

                    writeStream.Write(buffer, 0, bytesRead);

                    bytesRead = responseStream.Read(buffer, 0, Length);

                }

                responseStream.Close();

                writeStream.Close();

                requestFileDownload = null;

                responseFileDownload = null;

                return true;

            }

            catch (Exception ex)

            {

             

                return false;

            }

        }

Upload File

        private bool UploadfiletoFTP(string LocalfilePath, string FileName, string Directory, string Username, string Password)

        {

            try

            {

                FtpWebRequest ftpClient = (FtpWebRequest)FtpWebRequest.Create(Directory + "/" + FileName);

                ftpClient.Credentials = new System.Net.NetworkCredential(Username, Password);

                ftpClient.Method = System.Net.WebRequestMethods.Ftp.UploadFile;

                ftpClient.UseBinary = true;

                ftpClient.KeepAlive = true;

                System.IO.FileInfo fi = new System.IO.FileInfo(LocalfilePath + "/" + FileName);

                ftpClient.ContentLength = fi.Length;

                byte[] buffer = new byte[4097];

                int bytes = 0;

                int total_bytes = (int)fi.Length;

                System.IO.FileStream fs = fi.OpenRead();

                System.IO.Stream rs = ftpClient.GetRequestStream();

                while (total_bytes > 0)

                {

                    bytes = fs.Read(buffer, 0, buffer.Length);

                    rs.Write(buffer, 0, bytes);

                    total_bytes = total_bytes - bytes;

                }

                //fs.Flush();

                fs.Close();

                rs.Close();

                FtpWebResponse uploadResponse = (FtpWebResponse)ftpClient.GetResponse();

                string value = uploadResponse.StatusDescription;

                uploadResponse.Close();

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

Delete File

        private bool DeleteFtpFile(string Directory, string Username, string Password, string Filename)

        {

            try

            {

                FtpWebRequest requestFileDelete = (FtpWebRequest)WebRequest.Create(Directory + "/" + Filename);

                requestFileDelete.Credentials = new NetworkCredential(Username, Password);

                requestFileDelete.Method = WebRequestMethods.Ftp.DeleteFile;

                FtpWebResponse responseFileDelete = (FtpWebResponse)requestFileDelete.GetResponse();

                return true;

            }

            catch (Exception ex)

            {

                return false;

            }

        }

References:
http://www.techrepublic.com/blog/how-do-i/how-do-i-use-c-to-upload-and-download-files-from-an-ftp-server/ 
http://khanrahim.wordpress.com/2010/09/03/file-download-upload-delete-in-ftp-location-using-c/