Enviar un fichero por FTP usando C# para .NET

sendFtp.cs

string ftpServerIP = "ftp.example.com";
string ftpUserName = "username";
string ftpPassword = "password";
string filename = Server.MapPath("example.txt");
		
FileInfo objFile = new FileInfo(filename);

FtpWebRequest objFTPRequest;

// Create FtpWebRequest object 
objFTPRequest = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://" + ftpServerIP + "/" + objFile.Name));

// Set Credintials
objFTPRequest.Credentials = new NetworkCredential(ftpUserName, ftpPassword);

// By default KeepAlive is true, where the control connection is 
// not closed after a command is executed.
objFTPRequest.KeepAlive = false;

// Set the data transfer type.
objFTPRequest.UseBinary = true;

// Set content length
objFTPRequest.ContentLength = objFile.Length;

// Set request method
objFTPRequest.Method = WebRequestMethods.Ftp.UploadFile;

// Set buffer size
int intBufferLength = 16 * 1024;
byte[] objBuffer = new byte[intBufferLength];

// Opens a file to read
FileStream objFileStream = objFile.OpenRead();
		
try
{
  // Get Stream of the file
  Stream objStream = objFTPRequest.GetRequestStream();
		
  int len = 0;
		
  while ((len = objFileStream.Read(objBuffer, 0, intBufferLength)) != 0)
  {
    // Write file Content 
    objStream.Write(objBuffer, 0, len);
    
  }
		
  objStream.Close();
  objFileStream.Close();
  
} catch (Exception ex) {

  throw ex;
  
}