FtpWebRequest error: 550 Size not allowed in ASCII mode

Question

User-926160538 posted

Hi I have following problem while get File Size from the FTP path after file upload in specific FTP connection not all .

Exception Message : "The remote server returned an error: (550) File unavailable (e.g., file not found, no access)."

Inner Exception is : FtpWebRequest error: 550 Size not allowed in ASCII mode.

I have used following code to fetch FTP File size.

if (objFtpState.StatusDescription.Contains("Transfer complete"))
{
      req = (FtpWebRequest)FtpWebRequest.Create(txtUrl.Text + FileName);
      req.Credentials = new NetworkCredential(txtUser.Text, txtFTPPassword.Text);
      req.Method = WebRequestMethods.Ftp.GetFileSize();
  try
  {
       wresponse = (FtpWebResponse)req.GetResponse();
  }
  catch (WebException ex)
 {
   FtpWebResponse response = (FtpWebResponse)ex.Response;
       if (response.StatusCode == FtpStatusCode.ActionNotTakenFileUnavailable)
       {
            lblMsg.Text = "File not found in the FTP folder. Please contact administrator";
            lblMsg.ForeColor = Color.Red;
       }
  }

}

After changing piece of code from   req.Method = WebRequestMethods.Ftp.GetFileSize();  to  req.UseBinary = true; req.Method = WebRequestMethods.Ftp.DownloadFile; working without exception.

1.What configuration required in FTP connection to work existing code. ?

2.How it's working when download file ?

Please give me your valuable solution.

Answer 1

User36583972 posted

Hi Pandiyan,

1.What configuration required in FTP connection to work existing code. ?

2.How it's working when download file ?

You can ask the server how big the file is so you can keep track of the download percentage later on. Here are the two C# lines to modify this time:

FtpWebRequest request = FtpWebRequest.Create([FTPAddress]) as FtpWebRequest;
request.Method = WebRequestMethods.Ftp.ListDirectory;

if your FTP address like: ftp://myserver.com/myfile.txt, you can ask the FTP server for the filesize:

int dataLength = (int)request.GetResponse().ContentLength;

For more detailed : C# Download File FTP

The following links for your reference.

How to: Download files with FTP:
https://docs.microsoft.com/en-us/dotnet/framework/network-programming/how-to-download-files-with-ftp

Download File From FTP With Sub-Directories Using C#:
https://www.c-sharpcorner.com/blogs/download-file-from-ftp-with-subdirectories-using-c-sharp

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Best Regards,

Yong Lu