Adding page numbers to an existing PDF

JAVA

/*
    This file is part of the iText (R) project.
    Copyright (c) 1998-2023 Apryse Group NV
    Authors: Apryse Software.

    For more information, please contact iText Software at this address:
    [email protected]
 */
package com.itextpdf.samples.sandbox.stamper;

import com.itextpdf.kernel.pdf.PdfDocument;
import com.itextpdf.kernel.pdf.PdfReader;
import com.itextpdf.kernel.pdf.PdfWriter;
import com.itextpdf.layout.Document;
import com.itextpdf.layout.element.Paragraph;
import com.itextpdf.layout.properties.TextAlignment;
import com.itextpdf.layout.properties.VerticalAlignment;

import java.io.File;

public class StampPageXofY {
    public static final String DEST = "./target/sandbox/stamper/stamp_page_x_of_y.pdf";
    public static final String SRC = "./src/main/resources/pdfs/nameddestinations.pdf";

    public static void main(String[] args) throws Exception {
        File file = new File(DEST);
        file.getParentFile().mkdirs();

        new StampPageXofY().manipulatePdf(DEST);
    }

    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();
    }
}

C#

using System;
using System.IO;
using iText.Kernel.Pdf;
using iText.Layout;
using iText.Layout.Element;
using iText.Layout.Properties;

namespace iText.Samples.Sandbox.Stamper 
{
    public class StampPageXofY 
    {
        public static readonly String DEST = "results/sandbox/stamper/stamp_page_x_of_y.pdf";
        public static readonly String SRC = "../../../resources/pdfs/nameddestinations.pdf";

        public static void Main(String[] args) 
        {
            FileInfo file = new FileInfo(DEST);
            file.Directory.Create();
            
            new StampPageXofY().ManipulatePdf(DEST);
        }

        protected void ManipulatePdf(String dest) 
        {
            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("page " + i + " of " + numberOfPages),
                        559, 806, i, TextAlignment.RIGHT, VerticalAlignment.TOP, 0);
            }
            
            doc.Close();
        }
    }
}