Converting byte[] to pdf, rotating 180 degrees, back to byte[] and to response.outputstream - arrays

Question

I am trying to rotate a pdf document 180 degrees. Stored as a byte[] initially, it should be returned to the same, so that I can write it to the outputstream to our customers. This is my working code without rotation:
if (pdfurl == null)
return View(errorview);
var response = Response;
var getbyteresult = WebService.GetPDFAsByteArray(pdfurl);
MemoryStream ms = new MemoryStream(getbyteresult);
response.Clear();
response.ContentType = "application/pdf";
response.AddHeader("content-disposition",
"attachment;filename=label.pdf");
response.Buffer = true;
ms.WriteTo(response.OutputStream);
response.End();
return View("~/Views/Order/pdf.cshtml");
I've tried several libraries (itext, freesharp, spire), none of correctly manipulates and outputs.
Thanks in advance,
Rasmus Edvardsen
EDIT: The language is C#, and it's an MVC web application.
EDIT2: John's answer solved my problem - I also had an outdated verison of itextsharp, so that answers why most other solutions I tried failed the same way.
Never meant to come off as arrogant or anything, but I realise that's how it came out. Sorry and thanks.

Answer 1

Looking at your sample code it seems to me that you are using C# so here's a spoon feed for you.
Using iTextSharp:
private byte[] RotatePDF(byte[] pdfBytes, int rotation)
{
byte[] renderedBytes = null;
using (MemoryStream ms = new MemoryStream())
{
Document document = new Document();
PdfCopy pdf = new PdfCopy(document, ms);
PdfReader pdfReader = null;
PdfStamper stamper = null;
try
{
document.Open();
pdfReader = new PdfReader(pdfBytes);
stamper = new PdfStamper(pdfReader, ms);
for (int i = 1; i <= pdfReader.NumberOfPages; i++)
{
PdfDictionary pageDict = pdfReader.GetPageN(i);
PdfNumber pdfRotation = pageDict.GetAsNumber(PdfName.ROTATE);
if (pdfRotation != null)
{
rotation += pdfRotation.IntValue;
rotation %= 360;
}
pageDict.Put(PdfName.ROTATE, new PdfNumber(rotation));
}
pdf.AddDocument(pdfReader);
pdfReader.Close();
}
catch (Exception)
{
renderedBytes = null;
}
finally
{
if (pdfReader != null)
{
pdfReader.Close();
}
if (document != null)
{
document.Close();
}
}
renderedBytes = ms.ToArray();
return renderedBytes;
}
}
Usage:
var getbyteresult = WebService.GetPDFAsByteArray(pdfurl);
getbyteresult = RotatePDF(getbyteresult, 180); // 90 180 270 360