Hi 

try the below link

https://stackoverflow.com/questions/71574403/add-header-and-footer-on-all-pdf-pages-using-itext7-pdfhtml https://stackoverflow.com/questions/64486650/itext-7-add-header-and-footer-in-html-to-pdf/64486858#64486858

Thanks

Vinay(Codemantra99.com)

Part -2 

Customization

• You can customize the header and footer text, font, size, and position by modifying the HeaderFooterEventHandler class.

• For example, you can add a logo or dynamic content (e.g., date/time) to the header or footer.

Explaination of the process as shown below:

Part -1 

To add a header and footer to a PDF generated using iText7, you can use the PdfPageEventHelper class. This class allows you to define custom behaviour for events like adding content to a page (e.g., headers and footers).

Updated Code with Header and Footer

using iText.Html2pdf;
using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas;
using iText.Kernel.Pdf.Xobject;
using iText.Layout;
using iText.Layout.Element;
using iText.Layout.Properties;
using iText.Kernel.Events;
using iText.Kernel.Geom;
using System;
using System.IO;
using System.Text;

public class PdfGenerator
{
    public byte[] GeneratePdf(string htmlString)
    {
        using (var memoryStream = new MemoryStream())
        {
            var writer = new PdfWriter(memoryStream);
            var pdf = new PdfDocument(writer);

            // Add header and footer using PdfPageEventHelper
            var eventHandler = new HeaderFooterEventHandler();
            pdf.AddEventHandler(PdfDocumentEvent.START_PAGE, eventHandler);

            var converterProperties = new ConverterProperties();
            string basePath = AppDomain.CurrentDomain.BaseDirectory;
            converterProperties.SetBaseUri(basePath);

            using (var htmlStream = new MemoryStream(Encoding.UTF8.GetBytes(htmlString)))
            {
                HtmlConverter.ConvertToPdf(htmlStream, pdf, converterProperties);
            }

            return memoryStream.ToArray();
        }
    }

    // Custom event handler for header and footer
    private class HeaderFooterEventHandler : IEventHandler
    {
        public void HandleEvent(Event @event)
        {
            PdfDocumentEvent docEvent = (PdfDocumentEvent)@event;
            PdfDocument pdf = docEvent.GetDocument();
            PdfPage page = docEvent.GetPage();
            PdfCanvas canvas = new PdfCanvas(page.NewContentStreamBefore(), page.GetResources(), pdf);

            Rectangle pageSize = page.GetPageSize();
            float x = pageSize.GetX() + 20; // Left margin
            float y = pageSize.GetTop() - 20; // Top margin
            float footerY = pageSize.GetBottom() + 20; // Bottom margin

            // Add header
            canvas.BeginText()
                  .SetFontAndSize(iText.Kernel.Font.PdfFontFactory.CreateFont(), 12)
                  .MoveText(x, y)
                  .ShowText("This is the Header")
                  .EndText();

            // Add footer
            canvas.BeginText()
                  .SetFontAndSize(iText.Kernel.Font.PdfFontFactory.CreateFont(), 10)
                  .MoveText(x, footerY)
                  .ShowText("Page " + pdf.GetPageNumber(page))
                  .EndText();

            canvas.Release();
        }
    }
}

Explanation of the Code

1. HeaderFooterEventHandler Class:

   • This class implements the IEventHandler interface to handle page events.

   • The HandleEvent method is triggered for each page, allowing you to add custom content (header and footer).

2. Header:

   • The header is added at the top of each page using canvas.BeginText() and ShowText().

   • The position is set using x and y coordinates.

3. Footer:

   • The footer is added at the bottom of each page.

   • The page number is dynamically added using pdf.GetPageNumber(page).

4. Adding the Event Handler:

   • The HeaderFooterEventHandler is registered using pdf.AddEventHandler().

   • It listens for the START_PAGE event to add the header and footer before the page content is written.

5. Generating the PDF:

   • The HtmlConverter.ConvertToPdf() method converts the HTML to PDF.

   • The header and footer are automatically added to each page.

Sample code:

class Program
{
    static void Main(string[] args)
    {
        string htmlContent = "
Hello, World!
This is a sample PDF.
";
        var pdfGenerator = new PdfGenerator();
        byte[] pdfBytes = pdfGenerator.GeneratePdf(htmlContent);

        // Save the PDF to a file
        File.WriteAllBytes("output.pdf", pdfBytes);
        Console.WriteLine("PDF generated successfully!");
    }
}

Output

• The generated PDF will have a header ("This is the Header") at the top of each page.

• The footer will display the page number (e.g., "Page 1", "Page 2", etc.) at the bottom of each page.