How to get file size of multiple file download - asp.net

Question

I am writing an ASP.NET web application.
I calculate the total size of my PDF file which is mentioned below. What does this return? When I download a 2KB file, it returns a size of 2KB, which is correct. But when I download 2 files each of size 2KB, then the total size it returns is 2.16KB. Is that correct? Should it return 4KB?
StringReader reader = new StringReader(content);
MemoryStream ms = new MemoryStream();
Document doc = new Document(PageSize.A4, 50, 50, 30, 30);
HTMLWorker parser = new HTMLWorker(doc);
PdfWriter.GetInstance(doc, ms);
doc.Open();
try
{
parser.Parse(reader);
}
catch (Exception ex)
{
Paragraph paragraph = new Paragraph("Error! " + ex.Message);
paragraph.SetAlignment("center");
Chunk text = paragraph.Chunks[0] as Chunk;
if (text != null)
{
//text.Font.Color = iTextSharp.text.BaseColor.RED;
}
doc.Add(paragraph);
}
finally
{
doc.SetMargins(10, 10, 10, 10);
doc.Close();
}
Byte[] buffer = ms.GetBuffer();
if (buffer != null)
{
Response.ContentType = "application/pdf";
Response.AppendHeader("content-disposition", "attachment;filename=FileName.pdf");
//Response.AddHeader("content-length", buffer.Length.ToString());
Response.BinaryWrite(buffer);
}

Answer 1

Sounds like you're opening two files into the same buffer and expecting them to be appended one to the other. Instead, the second is replacing the first.
Try all this stand-alone in a simple C# program. If it doesn't work there, it clearly won't work in an ASP page. OTOH, if it does work there, but not in ASP, then its an ASP issue, not a problem with iTextSharp.
PS: I thought doc.close would close the stream used by PdfWriter as well. Looking at the code, it will by default (protected boolean closeStream = true; from the java source). Something might have called setCloseStream(false) somewhere along the line.
PPS: Stacking two PDFs into the same binary stream is Not A Good Idea. You need to write them out as separate attachments... at which point this whole issue is moot.