3-Heights™ PDF Toolbox – Entwicklerkomponente für die PDF Verarbeitung

using System.IO;
using PdfTools;
using PdfTools.Pdf;

namespace PdfToolboxSamples
{
    class AddPageNumbersSample
    {
        /// <summary>
        /// Copies a PDF document to a new document and adds a page number to each page
        /// </summary>
        /// <param name="inFilePath">Path to input PDF document</param>
        /// <param name="outFilePath">Path to resulting PDF document</param>
        public static void AddPageNumbers(string inFilePath, string outFilePath)
        {
            // 1. Initialize input and output documents
            using (Stream outFs = new FileStream(outFilePath, FileMode.Create, FileAccess.ReadWrite))
            using (Document outDoc = Document.Create(outFs, Conformance.Unknown, null))
            using (Stream inFs = new FileStream(inFilePath, FileMode.Open, FileAccess.Read))
            using (Document inDoc = Document.Open(inFs, null))
            {
                // 2. Copy metadata and output intent from input to output document
                outDoc.Metadata = outDoc.CopyMetadata(inDoc.Metadata);
                if (inDoc.OutputIntent != null) outDoc.OutputIntent = outDoc.CopyColorSpace(inDoc.OutputIntent);

                // Initialize page number
                int pageNumber = 1;

                // Create embedded font in output document
                using (Font font = outDoc.CreateSystemFont("Arial", "Bold", true))
                {
                    // 3. Loop through all pages of input document
                    foreach (Page inPage in inDoc.Pages)
                    {
                        // 4. Copy page from input to output document
                        using (Page outPage = outDoc.CopyPage(inPage, CopyOption.CopyLinks | CopyOption.CopyAnnotations | CopyOption.CopyFormFields | CopyOption.CopyOutlines))
                        {
                            // 5. Stamp page number on current page of output document and increase page number
                            AddPageNumberToPage(outDoc, outPage, font, pageNumber++);

                            // 6. Add page to output document
                            outDoc.Pages.Add(outPage);
                        }
                    }
                }
            }
        }

        /// <summary>
        /// Stamps a number to the bottom center of a page in the following format: "Page {pageNumber}"
        /// </summary>
        /// <param name="document">Document that contains page</param>
        /// <param name="page">Page onto which the number will be stamped</param>
        /// <param name="font">Font to use</param>
        /// <param name="number">Number to stamp onto the page</param>
        private static void AddPageNumberToPage(Document document, Page page, Font font, int number)
        {
            // Generate string to be stamped as page number
            string stampString = "Page " + number;

            // Create content generator for appending content to or transforming output page
            using (ContentGenerator contentGenerator = new ContentGenerator(page.Content, false))
            {
                // Create text object
                using (Text text = document.CreateText())
                {
                    // Create text generator with the given font, size and position
                    using (TextGenerator textGenerator = new TextGenerator(text, font, 10, null))
                    {
                        // Calculate position for centering text at bottom of page
                        double x = (page.Size.Width / 2) - (textGenerator.GetWidth(stampString) / 2);
                        double y = 8;

                        // Position the text
                        textGenerator.MoveTo(new Point { X = x, Y = y });

                        // Add page number string
                        textGenerator.Show(stampString);
                    }

                    // Paint the positioned text
                    contentGenerator.PaintText(text);
                }
            }
        }
    }
}