Adding page numbers to pdf using iTextSharp on second pass is not working - itext

Question

So as the title says I am trying to add page numbers to an existing pdf document, I have researched this problem and come up with a few tutorials/examples.
Here is the simplest example i can find
My code Compiles and runs successfully however the changes are not reflected in the pdf
my code
byte[] bytes = File.ReadAllBytes(filePath + ".pdf");
PdfReader pdfReader = new PdfReader(bytes);
using (MemoryStream ms = new MemoryStream())
{
using (PdfStamper stamper = new PdfStamper(pdfReader, ms,'\0',true))
{
int n = pdfReader.NumberOfPages;
for (int i = 1; i <= n; i++)
{
creatPageCountFooter(i + 1, n).WriteSelectedRows(0, -1, 34, 803, stamper.GetOverContent(i));
//ColumnText.ShowTextAligned(stamper.GetUnderContent(i), Element.ALIGN_RIGHT, new Phrase(i.ToString(), blackFont), 568f, 15f, 0);
}
ms.ToArray();
}
pdfReader.Close();
}
File.WriteAllBytes(filePath + ".pdf", bytes);
the function "creatPageCountFooter"
/**
* Create a header table with page X of Y
* #param count the page number
* #param Total the total number of pages
* #return a table that can be used as header
*/
protected PdfPTable creatPageCountFooter(int count,int Total)
{
PdfPTable pageCount = new PdfPTable(3);
pageCount.TotalWidth=250;
BaseFont bfTimes = BaseFont.CreateFont(BaseFont.TIMES_ROMAN, BaseFont.CP1252, false);
iTextSharp.text.Font times = new iTextSharp.text.Font(bfTimes, 6);
PdfPCell Cell = new PdfPCell(new Phrase(DateTime.Now.ToString("dd MMM yyyy"), times));
Cell.HorizontalAlignment = Element.ALIGN_RIGHT;
Cell.Border = 0;
pageCount.AddCell(Cell);
Cell = new PdfPCell(new Phrase(count.ToString() +" / "+ Total.ToString(), times));
Cell.HorizontalAlignment = Element.ALIGN_MIDDLE;
Cell.Border = 0;
pageCount.AddCell(Cell);
Cell = new PdfPCell(new Phrase("Company name " + DateTime.Now.ToString("yyyy"), times));
Cell.HorizontalAlignment = Element.ALIGN_MIDDLE;
Cell.Border = 0;
pageCount.AddCell(Cell);
return pageCount;
}
As a further note I have checked that this code actually runs and I have tried writing the file over the existing document or creating a new document and both times the changes don't reflect.
I will provide further details if required.

Answer 1

Your code writes the byte[] bytes to a file:
File.WriteAllBytes(filePath + ".pdf", bytes);
But the only code in which that variable is set, is the initial
byte[] bytes = File.ReadAllBytes(filePath + ".pdf");
Thus, it is not surprising that the changes are not reflected in the pdf result file because you simply write the original bytes unchanged.
I assume you meant to set bytes to the contents of the memory stream in this line
ms.ToArray();
but forgot the bytes =. Unfortunately, though, that array retrieval call happens too early, it is still inside the using PdfStamper block:
using (PdfStamper stamper = new PdfStamper(pdfReader, ms,'\0',true))
{
...
ms.ToArray();
}
Just like in the sample you refer to, the array has to be retrieved outside that using block, so that it is retrieved after the PdfStamper implicitly gets closed during disposal. Thus:
using (PdfStamper stamper = new PdfStamper(pdfReader, ms,'\0',true))
{
...
}
bytes = ms.ToArray();