The HiQPdfClient.HtmlToPdf class can be used to quickly create and save a PDF document to a file, to a stream or in a memory buffer but it will convert only one HTML document to a PDF document. Sometimes it is necessary to add multiple HTML documents to the same PDF document and eventualy overlapping the HTML content in multiple layers. This is possible with HiQPdf software using In Place HTML to PDF Object. The HTML objects are added to a PDF document which can be created by one of the methods described in PDF Documents topic.
A very interesting feature producing very special effects is that the content from a HTML document which doesn't have a background color or image will not have a background when converted to PDF. This makes possible to overlap multiple HTML documents in PDF while leaving visible the content underneath them.
In this demo you can see how to layout and overlay multiple HTML objects in the same PDF document. The HTML from URL 1 is laid out at the beginning of the PDF document and the URL 2 is laid out immediately after first HTML or on a new page if 'Layout on New Page' option is on. If the second HTML is laid out on a new page then there is the option to change the orientation of the new pages. The HTML code from the text box is finally overlaid in the first page of the PDF document at the given location.
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Microsoft.AspNetCore.Mvc; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Hosting; using HiQPdfClient; namespace HiQPdf_Demo.Controllers { public class ConvertManyHtmlToPdfController : Controller { IFormCollection m_formCollection; IWebHostEnvironment m_hostingEnvironment; public ConvertManyHtmlToPdfController(IWebHostEnvironment hostingEnvironment) { m_hostingEnvironment = hostingEnvironment; } // GET: ConvertManyHtmlToPdf public ActionResult Index() { return View(); } [HttpPost] public ActionResult ConvertToPdf(IFormCollection collection) { m_formCollection = collection; string serverIP = collection["textBoxServerIP"]; uint serverPort = uint.Parse(collection["textBoxServerPort"]); string serverPassword = collection["textBoxServerPassword"]; // create an empty PDF document PdfDocument document = new PdfDocument(serverIP, serverPort); // use server password if necessary if (serverPassword.Length > 0) document.ServerPassword = serverPassword; // set a demo serial number document.SerialNumber = "YCgJMTAE-BiwJAhIB-EhlWTlBA-UEBRQFBA-U1FOUVJO-WVlZWQ=="; // add a page to document PdfPage page1 = document.AddPage(PdfPageSize.A4, new PdfMargins(5), PdfPageOrientation.Portrait); try { // set the document header and footer before adding any objects to document SetHeader(document); SetFooter(document); // layout the HTML from URL 1 PdfHtml html1 = new PdfHtml(collection["textBoxUrl1"]); html1.WaitBeforeConvert = 2; page1.Layout(html1); if (collection["checkBoxNewPage"].Count > 0) { // URL 2 is laid out on a new page with the selected orientation PdfPage page2 = document.AddPage(PdfPageSize.A4, new PdfMargins(5), GetSelectedPageOrientation()); // layout the HTML from URL 2 PdfHtml html2 = new PdfHtml(collection["textBoxUrl2"]); html2.WaitBeforeConvert = 2; page2.Layout(html2); } else { // URL 2 is laid out immediately after URL 1 // using the document realtive flow layout PdfHtml html2 = new PdfHtml(collection["textBoxUrl2"]); html2.WaitBeforeConvert = 2; document.Layout(html2); } // write the PDF document to a memory buffer byte[] pdfBuffer = document.WriteToMemory(); FileResult fileResult = new FileContentResult(pdfBuffer, "application/pdf"); fileResult.FileDownloadName = "ConvertManyHtmlToPdf.pdf"; return fileResult; } finally { document.Close(); } } private void SetHeader(PdfDocument document) { if (m_formCollection["checkBoxAddHeader"].Count == 0) return; // create the document header document.CreateHeaderCanvas(50); // add PDF objects to the header canvas string headerImageFile = m_hostingEnvironment.WebRootPath + "/DemoFiles/Images/HiQPdfLogo.png"; PdfImage logoHeaderImage = new PdfImage(5, 5, 40, headerImageFile); document.Header.Layout(logoHeaderImage); // layout HTML in header PdfHtml headerHtml = new PdfHtml(50, 5, @"<span style=""color:Navy; font-family:Times New Roman; font-style:italic""> Quickly Create High Quality PDFs with </span><a href=""http://www.hiqpdf.com"">HiQPdf</a>", null); headerHtml.FitDestHeight = true; headerHtml.FontEmbedding = true; document.Header.Layout(headerHtml); PdfPage startPage = document.Pages[0]; float headerWidth = startPage.Size.Width - startPage.Margins.Left - startPage.Margins.Right; float headerHeight = document.Header.Height; // create a border for header PdfRectangle borderRectangle = new PdfRectangle(1, 1, headerWidth - 2, headerHeight - 2); borderRectangle.LineStyle.LineWidth = 0.5f; borderRectangle.ForeColor = PdfColor.Navy; document.Header.Layout(borderRectangle); } private void SetFooter(PdfDocument document) { if (m_formCollection["checkBoxAddFooter"].Count == 0) return; //create the document footer document.CreateFooterCanvas(50); // layout HTML in footer PdfHtml footerHtml = new PdfHtml(5, 5, @"<span style=""color:Navy; font-family:Times New Roman; font-style:italic""> Quickly Create High Quality PDFs with </span><a href=""http://www.hiqpdf.com"">HiQPdf</a>", null); footerHtml.FitDestHeight = true; footerHtml.FontEmbedding = true; document.Footer.Layout(footerHtml); PdfPage startPage = document.Pages[0]; float footerWidth = startPage.Size.Width - startPage.Margins.Left - startPage.Margins.Right; float footerHeight = document.Footer.Height; // add page numbering PdfFont pageNumberingFont = new PdfFont("Times New Roman", 8, true); PdfText pageNumberingText = new PdfText(5, footerHeight - 12, "Page {CrtPage} of {PageCount}", pageNumberingFont); pageNumberingText.HorizontalAlign = PdfTextHAlign.Center; pageNumberingText.EmbedSystemFont = true; pageNumberingText.ForeColor = PdfColor.DarkGreen; document.Footer.Layout(pageNumberingText); string footerImageFile =m_hostingEnvironment.WebRootPath + "/DemoFiles/Images/HiQPdfLogo.png"; PdfImage logoFooterImage = new PdfImage(footerWidth - 40 - 5, 5, 40, footerImageFile); document.Footer.Layout(logoFooterImage); // create a border for footer PdfRectangle borderRectangle = new PdfRectangle(1, 1, footerWidth - 2, footerHeight - 2); borderRectangle.LineStyle.LineWidth = 0.5f; borderRectangle.ForeColor = PdfColor.DarkGreen; document.Footer.Layout(borderRectangle); } private PdfPageOrientation GetSelectedPageOrientation() { return m_formCollection["dropDownListPageOrientations"] == "Portrait" ? PdfPageOrientation.Portrait : PdfPageOrientation.Landscape; } } }