How to get the total page number in iText7 when adding that info to the document footer? - footer

Question

In iTextSharp, we can override the OnCloseDocument() event and add the Page # of #total on the footer of the document. However, the PdfDocument does not have this document close event anymore. Since we cannot determine the total number of pages while adding new pages, how can we determine this total number and put it on the footer while generating the document?
I've seen some suggestions with brute force method: after the PDF document is generated and before it's flushed, use PdfReader to read through it to get the total number before updating the footer. Is this the only way? Is there any better way of doing this?
Thanks.

Answer 1

That is one of the ways of doing it.
Another way of doing that is described in this code sample:
protected void manipulatePdf(String dest) throws Exception {
PdfDocument pdfDoc = new PdfDocument(new PdfReader(SRC), new PdfWriter(dest));
Document doc = new Document(pdfDoc);
int numberOfPages = pdfDoc.getNumberOfPages();
for (int i = 1; i <= numberOfPages; i++) {
// Write aligned text to the specified by parameters point
doc.showTextAligned(new Paragraph(String.format("page %s of %s", i, numberOfPages)),
559, 806, i, TextAlignment.RIGHT, VerticalAlignment.TOP, 0);
}
doc.close();
}
In that code sample you would add the footer after creating and flushing the PDF. This is a very simple and easy way of doing this request.

Answer 2

Another way of doing that is with IEventHandler.
PdfWriter writer = new PdfWriter(myMemoryStream);
pdf.AddEventHandler(PdfDocumentEvent.END_PAGE, new TextFooterEventHandler(document));
then :
public class TextFooterEventHandler : IEventHandler
{
protected Document doc;
public TextFooterEventHandler(Document doc)
{
this.doc = doc;
}
public void HandleEvent(Event currentEvent)
{
var docEvent = (PdfDocumentEvent)currentEvent;
var pageSize = docEvent.GetPage().GetPageSize();
var fonts = new FontHelper();
var font = fonts.Label();
int pageNum = docEvent.GetDocument().GetPageNumber(docEvent.GetPage());
float coordX = ((pageSize.GetLeft() + doc.GetLeftMargin())
+ (pageSize.GetRight() - doc.GetRightMargin())) / 2;
float footerY = doc.GetBottomMargin();
Canvas canvas = new Canvas(docEvent.GetPage(), pageSize);
canvas
.SetFont(font)
.SetFontSize(8)
.ShowTextAligned((("Page " + pageNum.ToString())), coordX + 250, footerY - 40, TextAlignment.CENTER)
.SetLineThrough()
.Close();
}
}