MVC FileStreamResult is not downloading file with custom file name

Question

The pdf downloads fine but with a random name - 9619012021194536.pdf
I'm trying to set a custom name but it is not working. The downloaded file still has a random name instead of the custom name being set in code.

public ActionResult Appointment(int id)
        {
            Stream stream = null;
            string fileName = "";

            try
            {
                stream = GenerateAppointmentReport(id);
                fileName = id + "_" + DateTime.Now.ToString("ddMMyyyyHHmmss") + ".pdf";                    
            }
            catch (Exception ex)
            {
                
            }

            return new FileStreamResult(stream, MimeMapping.GetMimeMapping(fileName))
            { FileDownloadName = fileName };
        }

Answer 1

You can use this code:

public ActionResult Appointment(int id)
{
  Stream stream = null;
  string fileName = "";

  try
  {
     stream = GenerateAppointmentReport(id);
     fileName = id + "_" + DateTime.Now.ToString("ddMMyyyyHHmmss") + ".pdf";                    
  }
  catch (Exception ex)
  {
                    
  }
  return new FileStreamResult(stream, "binary") { FileDownloadName = fileName };
}

I used this code and the file was downloaded with the specific name I mentioned.