C# How to upload large files to ftp site

Question

I am developing an windows application for backup(Files and sql server database). Now i need to upload these files(.rar files) to my ftp site. For uploading i use this code.

Code

string file = "D:\\RP-3160-driver.zip";
//opening the file for read.
string uploadFileName = "", uploadUrl = "";
uploadFileName = new FileInfo(file).Name;
uploadUrl = "ftp://ftp.Sitename.com/tempFiles/";
FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read);
try
{
   long FileSize = new FileInfo(file).Length; // File size of file being uploaded.

   Byte[] buffer = new Byte[FileSize];
   fs.Read(buffer, 0, buffer.Length);
   fs.Close();
   fs = null;

   string ftpUrl = string.Format("{0}/{1}", uploadUrl, uploadFileName);
   FtpWebRequest requestObj = FtpWebRequest.Create(ftpUrl) as FtpWebRequest;
   requestObj.Method = WebRequestMethods.Ftp.UploadFile;
   requestObj.Credentials = new NetworkCredential("usernam", "password");
   Stream requestStream = requestObj.GetRequestStream();
   requestStream.Write(buffer, 0, buffer.Length);
   requestStream.Flush();
   requestStream.Close();
   requestObj = null;
   MessageBox.Show("File upload/transfer Successed.", "Successed", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
catch (Exception ex)
{
   if (fs != null)
   {
      fs.Close();
   }
   MessageBox.Show("File upload/transfer Failed.\r\nError Message:\r\n" + ex.Message, "Successed", MessageBoxButtons.OK, MessageBoxIcon.Information);
}

This code uploads only those files which has size < 5 Mb. But i need to upload larger then 500Mb to 1Gb files. So can any one help me.

Have you determine the reason your code is not working. What exactly happens when your program stops uploading the file? — Security Hound, Apr 17 '13 at 16:06

score 9 · Accepted Answer · edited Jan 07 '20 at 16:33

For larger files you may choose to read the file stream and write it to the output stream as you read it.

FileStream fs = null;
Stream rs = null;

try 
{
    string file = "D:\\RP-3160-driver.zip";
    string uploadFileName = new FileInfo(file).Name;
    string uploadUrl = "ftp://ftp.Sitename.com/tempFiles/";
    fs = new FileStream(file, FileMode.Open, FileAccess.Read);

    string ftpUrl = string.Format("{0}/{1}", uploadUrl, uploadFileName);
    FtpWebRequest requestObj = FtpWebRequest.Create(ftpUrl) as FtpWebRequest;
    requestObj.Method = WebRequestMethods.Ftp.UploadFile;
    requestObj.Credentials = new NetworkCredential("usernam", "password");
    rs = requestObj.GetRequestStream();

    byte[] buffer = new byte[8092];
    int read = 0;
    while ((read = fs.Read(buffer, 0, buffer.Length)) != 0)
    {
       rs.Write(buffer, 0, read);
    }
    rs.Flush();
}
catch (Exception exception) 
{

    MessageBox.Show("File upload/transfer Failed.\r\nError Message:\r\n" + exception.Message, "Succeeded", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
finally 
{
    if (fs != null)
    {
        fs.Close();
        fs.Dispose();
    }

    if (rs != null)
    {
        rs.Close();
        rs.Dispose();
    }
}

I have used same code for transfer but application throw "Unable to write data to the transport connection: An existing connection was forcibly closed by the remote host." Upload data size is: -310MB — Abhay.Patil, Sep 27 '19 at 10:50
@Abhay.Patil Probably there is a setting in the FTP server-side that restricts the upload of files that are bigger than 310MB. Are you using IIS to set up an FTP server? — Nithin B, Jun 14 '20 at 04:45

score 4 · Answer 2 · answered Apr 17 '13 at 11:58

4

Stream class has a nice Method CopyTo.

You don't need to read and write from/to streams. Just use fs.CopyTo(requestStream);

With this method, you don't have to declare large arrays like new Byte[FileSize];

answered Apr 17 '13 at 11:58

I4V

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Man you are the angel in my life! Seriusly thank you! – khaosdoctor Apr 13 '15 at 18:19
I was worried about setting the FtpWebRequest.ContentLength Property, but apparently the value [is ignored by the FtpWebRequest class](https://msdn.microsoft.com/en-us/library/system.net.ftpwebrequest.contentlength(v=vs.110).aspx) – mcdon Jul 24 '18 at 20:39

C# How to upload large files to ftp site

Code

2 Answers2

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