如何使用C#在PDF中添加页码

using IronPdf;

class Program
{
    static void Main(string[] args)
    {
        // Create a new HtmlToPdf renderer instance
        var renderer = new HtmlToPdf();

        // Define the HTML content with a header
        string header = "<h1>Hello IronPDF!</h1>";

        // Render the HTML as a PDF document
        PdfDocument pdf = renderer.RenderHtmlAsPdf(header);

        // Define the HTML footer with page numbers
        HtmlHeaderFooter htmlFooter = new HtmlHeaderFooter()
        {
            HtmlFragment = "<center><i>{page} of {total-pages}</i></center>"
        };

        // Add footer to the PDF
        pdf.AddHtmlFooters(htmlFooter);

        // Save the PDF document to a file
        pdf.SaveAs("output.pdf");
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main(ByVal args() As String)
		' Create a new HtmlToPdf renderer instance
		Dim renderer = New HtmlToPdf()

		' Define the HTML content with a header
		Dim header As String = "<h1>Hello IronPDF!</h1>"

		' Render the HTML as a PDF document
		Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(header)

		' Define the HTML footer with page numbers
		Dim htmlFooter As New HtmlHeaderFooter() With {.HtmlFragment = "<center><i>{page} of {total-pages}</i></center>"}

		' Add footer to the PDF
		pdf.AddHtmlFooters(htmlFooter)

		' Save the PDF document to a file
		pdf.SaveAs("output.pdf")
	End Sub
End Class

using System.IO;
using iTextSharp.text;
using iTextSharp.text.pdf;

namespace ConsoleApp1
{
    internal class Program
    {
        static void Main(string[] args)
        {
            // Create a new PDF document
            Document doc = new Document();
            PdfWriter writer = PdfWriter.GetInstance(doc, new FileStream("output.pdf", FileMode.Create));

            // Open the document to add content
            doc.Open();
            doc.Add(new Paragraph("Hello, world!"));

            // Attach page number event to PDF writer
            writer.PageEvent = new PageNumberEventHandler();

            // Close the document
            doc.Close();
        }
    }

    public class PageNumberEventHandler : PdfPageEventHelper
    {
        public override void OnOpenDocument(PdfWriter writer, Document document)
        {
            base.OnOpenDocument(writer, document);
        }

        public override void OnEndPage(PdfWriter writer, Document document)
        {
            base.OnEndPage(writer, document);

            // Create a table to hold the page number
            PdfPTable table = new PdfPTable(1);
            table.TotalWidth = 300f;
            table.HorizontalAlignment = Element.ALIGN_CENTER;

            PdfPCell cell = new PdfPCell(new Phrase($"Page {writer.PageNumber}"));
            cell.Border = 0;
            table.AddCell(cell);

            // Write the table at the bottom of the page
            table.WriteSelectedRows(0, -1, 150f, document.Bottom, writer.DirectContent);
        }

        public override void OnCloseDocument(PdfWriter writer, Document document)
        {
            base.OnCloseDocument(writer, document);
        }
    }
}

Imports System.IO
Imports iTextSharp.text
Imports iTextSharp.text.pdf

Namespace ConsoleApp1
	Friend Class Program
		Shared Sub Main(ByVal args() As String)
			' Create a new PDF document
			Dim doc As New Document()
			Dim writer As PdfWriter = PdfWriter.GetInstance(doc, New FileStream("output.pdf", FileMode.Create))

			' Open the document to add content
			doc.Open()
			doc.Add(New Paragraph("Hello, world!"))

			' Attach page number event to PDF writer
			writer.PageEvent = New PageNumberEventHandler()

			' Close the document
			doc.Close()
		End Sub
	End Class

	Public Class PageNumberEventHandler
		Inherits PdfPageEventHelper

		Public Overrides Sub OnOpenDocument(ByVal writer As PdfWriter, ByVal document As Document)
			MyBase.OnOpenDocument(writer, document)
		End Sub

		Public Overrides Sub OnEndPage(ByVal writer As PdfWriter, ByVal document As Document)
			MyBase.OnEndPage(writer, document)

			' Create a table to hold the page number
			Dim table As New PdfPTable(1)
			table.TotalWidth = 300F
			table.HorizontalAlignment = Element.ALIGN_CENTER

			Dim cell As New PdfPCell(New Phrase($"Page {writer.PageNumber}"))
			cell.Border = 0
			table.AddCell(cell)

			' Write the table at the bottom of the page
			table.WriteSelectedRows(0, -1, 150F, document.Bottom, writer.DirectContent)
		End Sub

		Public Overrides Sub OnCloseDocument(ByVal writer As PdfWriter, ByVal document As Document)
			MyBase.OnCloseDocument(writer, document)
		End Sub
	End Class
End Namespace