Excel file corrupts while uploading and downloading from FTP server

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HI ,

There are TWO Excel Files in my Program which I am trying to upload to a FTP server and then later Download it  and its getting uploaded and downloaded with no error but when i try to open the file i get error message its corrupted or not in correct format i.e

"file format or extension not valid. Verify that the file has not been corrupted and that the file extension matches the format of the file."

the code i am using for upload is as follows :

What I have tried:

C#

private void FtpUploadFile(string filename)
        {
            string user_name = "username";
            string password = "password";
            
            // Get the object used to communicate with the server.
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://ftp.ftpsite.com/excel.xlsx");
            request.Method = WebRequestMethods.Ftp.UploadFile;

            // Get network credentials.
            request.Credentials = new NetworkCredential(user_name, password);

            // Read the file's contents into a byte array.
            byte[] bytes = System.IO.File.ReadAllBytes(filename);

            // Write the bytes into the request stream.
            request.ContentLength = bytes.Length;
            using (Stream request_stream = request.GetRequestStream())
            {
                request_stream.Write(bytes, 0, bytes.Length);
                request_stream.Close();
            }
        }

        private void btnupload_Click(object sender, EventArgs e)
        {
            try
            {
                this.Cursor = Cursors.WaitCursor;
                lblStatus.Text = "Working...";
                Application.DoEvents();

                FtpUploadFile(txtFile.Text);

                lblStatus.Text = "Done";
            }
            catch (Exception ex)
            {
                lblStatus.Text = "Error";
                MessageBox.Show(ex.Message);
            }
            finally
            {
                this.Cursor = Cursors.Default;
            }

            
        }

Help please.

Posted 28-Feb-17 18:50pm

Nazneen s

Updated 28-Feb-17 20:33pm

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Comments

Garth J Lancaster 1-Mar-17 0:54am

I'm not sure how to (or if you can do it with) FtpWebRequest, but, I'd be looking at if you're transferring in Text or Binary mode to start with (it should be Binary)

Nazneen s 1-Mar-17 1:02am

did not quite get you there @garth

Garth J Lancaster 1-Mar-17 1:17am

see this https://msdn.microsoft.com/en-us/library/system.net.ftpwebrequest.usebinary(v=vs.110).aspx

Nazneen s 1-Mar-17 1:54am

still not working garth i tried

request.Method = WebRequestMethods.Ftp.UploadFile;
request.UsePassive = true;
request.KeepAlive = false;(and true both)
request.UseBinary = true;

Garth J Lancaster 1-Mar-17 2:03am

I take it you've checked the obvious,

a) file size in bytes before ftp = file size in bytes after
b) maybe generate a hash of the file on each 'side' and compare

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Nazneen s · Accepted Answer · 2017-02-28T20:33:00

i myself came up with the solution just declare all the variables at start ad paste this :

FtpWebRequest ftpClient = (FtpWebRequest)FtpWebRequest.Create(ftpurl + "/" + filename);
            ftpClient.Credentials = new System.Net.NetworkCredential(ftpusername, ftppassword);
            ftpClient.Method = System.Net.WebRequestMethods.Ftp.UploadFile;
            ftpClient.UseBinary = true;
            ftpClient.KeepAlive = true;
            System.IO.FileInfo fi = new System.IO.FileInfo(fileurl);
            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();

Thanks for the help.