iTextSharp C# HTML to PDF Alternative for .NET Core

using IronPdf;

public class Program
{
    static void Main(string[] args)
    {
        // Create a new ChromePdfRenderer instance for rendering HTML to PDF
        ChromePdfRenderer renderer = new ChromePdfRenderer();

        // Render the specified HTML file as a PDF document
        PdfDocument pdf = renderer.RenderHtmlFileAsPdf("example.html");

        // Save the rendered PDF to the specified file path
        pdf.SaveAs("HtmlToPdf.pdf");
    }
}

Imports IronPdf

Public Class Program
	Shared Sub Main(ByVal args() As String)
		' Create a new ChromePdfRenderer instance for rendering HTML to PDF
		Dim renderer As New ChromePdfRenderer()

		' Render the specified HTML file as a PDF document
		Dim pdf As PdfDocument = renderer.RenderHtmlFileAsPdf("example.html")

		' Save the rendered PDF to the specified file path
		pdf.SaveAs("HtmlToPdf.pdf")
	End Sub
End Class

using IronPdf;

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

        // Render the specified URL as a PDF document
        PdfDocument pdf = renderer.RenderUrlAsPdf("https://www.apple.com");

        // Save the rendered PDF to the specified file path
        pdf.SaveAs("UrlToPdf.pdf");
    }
}

Imports IronPdf

Public Class Program
	Shared Sub Main(ByVal args() As String)
		' Create a new ChromePdfRenderer instance
		Dim renderer As New ChromePdfRenderer()

		' Render the specified URL as a PDF document
		Dim pdf As PdfDocument = renderer.RenderUrlAsPdf("https://www.apple.com")

		' Save the rendered PDF to the specified file path
		pdf.SaveAs("UrlToPdf.pdf")
	End Sub
End Class

using IronPdf;
using IronPdf.Signing;
using System.Security.Cryptography.X509Certificates;
using IronSoftware.Drawing;

public class Program
{
    static void Main(string[] args)
    {
        // Load the certificate used for signing the PDF
        X509Certificate2 cert = new X509Certificate2("IronSoftware.pfx", "your-password", X509KeyStorageFlags.Exportable);

        // Create a PdfSignature instance and set the signature image
        var sig = new PdfSignature(cert);
        sig.SignatureImage = new PdfSignatureImage("IronPdf.png", 0, new Rectangle(150, 100, 350, 250));

        // Sign the existing PDF file and save the signed version
        sig.SignPdfFile("product_report.pdf");
    }
}

Imports IronPdf
Imports IronPdf.Signing
Imports System.Security.Cryptography.X509Certificates
Imports IronSoftware.Drawing

Public Class Program
	Shared Sub Main(ByVal args() As String)
		' Load the certificate used for signing the PDF
		Dim cert As New X509Certificate2("IronSoftware.pfx", "your-password", X509KeyStorageFlags.Exportable)

		' Create a PdfSignature instance and set the signature image
		Dim sig = New PdfSignature(cert)
		sig.SignatureImage = New PdfSignatureImage("IronPdf.png", 0, New Rectangle(150, 100, 350, 250))

		' Sign the existing PDF file and save the signed version
		sig.SignPdfFile("product_report.pdf")
	End Sub
End Class

using iText.Html2pdf;
using System.IO;

public class Program
{
    static void Main(string[] args)
    {
        // Open the HTML file stream
        using (FileStream htmlSource = File.Open("example.html", FileMode.Open))
        // Create the output PDF file stream
        using (FileStream pdf = File.Open("HtmlToPdfOutput.pdf", FileMode.Create))
        {
            // Initialize ConverterProperties for HTML to PDF conversion
            ConverterProperties converterProperties = new ConverterProperties();

            // Convert the HTML source to a PDF document
            HtmlConverter.ConvertToPdf(htmlSource, pdf, converterProperties);

            // Close the PDF file
            pdf.Close();
        }
    }
}

Imports iText.Html2pdf
Imports System.IO

Public Class Program
	Shared Sub Main(ByVal args() As String)
		' Open the HTML file stream
		Using htmlSource As FileStream = File.Open("example.html", FileMode.Open)
		' Create the output PDF file stream
		Using pdf As FileStream = File.Open("HtmlToPdfOutput.pdf", FileMode.Create)
			' Initialize ConverterProperties for HTML to PDF conversion
			Dim converterProperties As New ConverterProperties()

			' Convert the HTML source to a PDF document
			HtmlConverter.ConvertToPdf(htmlSource, pdf, converterProperties)

			' Close the PDF file
			pdf.Close()
		End Using
		End Using
	End Sub
End Class

using System;
using System.Net.Http;
using System.IO;
using iText.Html2pdf;

public class Program
{
    public static async System.Threading.Tasks.Task Main(string[] args)
    {
        string url = "https://www.apple.com";  // Replace with your target URL
        string outputPdfPath = "output.pdf";

        try
        {
            // Download HTML content from the URL
            using (HttpClient client = new HttpClient())
            {
                string htmlContent = await client.GetStringAsync(url);

                // Convert HTML to PDF
                using (FileStream pdfStream = new FileStream(outputPdfPath, FileMode.Create))
                {
                    ConverterProperties properties = new ConverterProperties();
                    HtmlConverter.ConvertToPdf(htmlContent, pdfStream, properties);
                }
            }

            Console.WriteLine("PDF created successfully: " + outputPdfPath);
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error: " + ex.Message);
        }
    }
}

Imports System
Imports System.Net.Http
Imports System.IO
Imports iText.Html2pdf

Public Class Program
	Public Shared Async Function Main(ByVal args() As String) As System.Threading.Tasks.Task
		Dim url As String = "https://www.apple.com" ' Replace with your target URL
		Dim outputPdfPath As String = "output.pdf"

		Try
			' Download HTML content from the URL
			Using client As New HttpClient()
				Dim htmlContent As String = Await client.GetStringAsync(url)

				' Convert HTML to PDF
				Using pdfStream As New FileStream(outputPdfPath, FileMode.Create)
					Dim properties As New ConverterProperties()
					HtmlConverter.ConvertToPdf(htmlContent, pdfStream, properties)
				End Using
			End Using

			Console.WriteLine("PDF created successfully: " & outputPdfPath)
		Catch ex As Exception
			Console.WriteLine("Error: " & ex.Message)
		End Try
	End Function
End Class

using System.Security.Cryptography.X509Certificates;
using iText.Kernel.Pdf;
using iText.Signatures;
using iText.Bouncycastle.Crypto;
using iText.Commons.Bouncycastle.Cert;
using iText.Commons.Bouncycastle.Crypto;
using Org.BouncyCastle.Pkcs;
using Org.BouncyCastle.Crypto;
using iText.Bouncycastle.X509;
using iText.Kernel.Crypto;
using System.IO;

public class Program
{
    static void Main(string[] args)
    {
        string inputPdf = "input.pdf";       // PDF to be signed
        string outputPdf = "signed_output.pdf";  // Signed PDF output
        string pfxFile = "IronSoftware.pfx";  // Path to your PFX certificate
        string password = "Passw0rd";   // Password for PFX file

        try
        {
            // Load your certificate
            Pkcs12Store ks = new Pkcs12StoreBuilder().Build();
            using (FileStream fs = new FileStream(pfxFile, FileMode.Open, FileAccess.Read))
            {
                ks.Load(fs, password.ToCharArray());
            }

            string alias = null;
            foreach (string al in ks.Aliases)
            {
                if (ks.IsKeyEntry(al))
                {
                    alias = al;
                    break;
                }
            }

            if (alias == null)
            {
                throw new Exception("Alias not found in the PFX file.");
            }

            ICipherParameters pk = ks.GetKey(alias).Key;
            X509CertificateEntry[] chain = ks.GetCertificateChain(alias);

            // Convert BouncyCastle certificates to iText certificates
            var itextCertChain = new IX509Certificate[chain.Length];
            for (int i = 0; i < chain.Length; i++)
            {
                itextCertChain[i] = new X509CertificateBC(chain[i].Certificate);
            }

            // Create output PDF with signed content
            using (PdfReader reader = new PdfReader(inputPdf))
            using (FileStream os = new FileStream(outputPdf, FileMode.Create, FileAccess.Write))
            {
                PdfSigner signer = new PdfSigner(reader, os, new StampingProperties().UseAppendMode());

                // Set up the external signature (private key + digest algorithm)
                IPrivateKey iTextPrivateKey = new PrivateKeyBC(pk);
                IExternalSignature pks = new PrivateKeySignature(iTextPrivateKey, DigestAlgorithms.SHA256);
                IExternalDigest digest = new BouncyCastleDigest();

                // Perform the signing (detached signature)
                signer.SignDetached(digest, pks, itextCertChain, null, null, null, 0, PdfSigner.CryptoStandard.CMS);
            }

            Console.WriteLine($"PDF digitally signed successfully: {outputPdf}");
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error signing PDF: {ex.Message}");
        }
    }
}

Imports System.Security.Cryptography.X509Certificates
Imports iText.Kernel.Pdf
Imports iText.Signatures
Imports iText.Bouncycastle.Crypto
Imports iText.Commons.Bouncycastle.Cert
Imports iText.Commons.Bouncycastle.Crypto
Imports Org.BouncyCastle.Pkcs
Imports Org.BouncyCastle.Crypto
Imports iText.Bouncycastle.X509
Imports iText.Kernel.Crypto
Imports System.IO

Public Class Program
	Shared Sub Main(ByVal args() As String)
		Dim inputPdf As String = "input.pdf" ' PDF to be signed
		Dim outputPdf As String = "signed_output.pdf" ' Signed PDF output
		Dim pfxFile As String = "IronSoftware.pfx" ' Path to your PFX certificate
		Dim password As String = "Passw0rd" ' Password for PFX file

		Try
			' Load your certificate
			Dim ks As Pkcs12Store = (New Pkcs12StoreBuilder()).Build()
			Using fs As New FileStream(pfxFile, FileMode.Open, FileAccess.Read)
				ks.Load(fs, password.ToCharArray())
			End Using

			Dim [alias] As String = Nothing
			For Each al As String In ks.Aliases
				If ks.IsKeyEntry(al) Then
					[alias] = al
					Exit For
				End If
			Next al

			If [alias] Is Nothing Then
				Throw New Exception("Alias not found in the PFX file.")
			End If

			Dim pk As ICipherParameters = ks.GetKey([alias]).Key
			Dim chain() As X509CertificateEntry = ks.GetCertificateChain([alias])

			' Convert BouncyCastle certificates to iText certificates
			Dim itextCertChain = New IX509Certificate(chain.Length - 1){}
			For i As Integer = 0 To chain.Length - 1
				itextCertChain(i) = New X509CertificateBC(chain(i).Certificate)
			Next i

			' Create output PDF with signed content
			Using reader As New PdfReader(inputPdf)
			Using os As New FileStream(outputPdf, FileMode.Create, FileAccess.Write)
				Dim signer As New PdfSigner(reader, os, (New StampingProperties()).UseAppendMode())

				' Set up the external signature (private key + digest algorithm)
				Dim iTextPrivateKey As IPrivateKey = New PrivateKeyBC(pk)
				Dim pks As IExternalSignature = New PrivateKeySignature(iTextPrivateKey, DigestAlgorithms.SHA256)
				Dim digest As IExternalDigest = New BouncyCastleDigest()

				' Perform the signing (detached signature)
				signer.SignDetached(digest, pks, itextCertChain, Nothing, Nothing, Nothing, 0, PdfSigner.CryptoStandard.CMS)
			End Using
			End Using

			Console.WriteLine($"PDF digitally signed successfully: {outputPdf}")
		Catch ex As Exception
			Console.WriteLine($"Error signing PDF: {ex.Message}")
		End Try
	End Sub
End Class