HelloWorldHtml.cs 
  1. //
  2. // This code is part of Document Solutions for PDF demos.
  3. // Copyright (c) MESCIUS inc. All rights reserved.
  4. //
  5. using System;
  6. using System.IO;
  7. using System.Drawing;
  8. using GrapeCity.Documents.Pdf;
  9. using GrapeCity.Documents.Text;
  10. using GrapeCity.Documents.Html;
  11.  
  12. namespace DsPdfWeb.Demos
  13. {
  14.     // This sample shows how to render an HTML string.
  15.     //
  16.     // Adding DsHtml to your projects:
  17.     // - Public classes and extension methods that enable rendering HTML
  18.     //   are provided by the GrapeCity.Documents.Html (DsHtml) package.
  19.     // - DsHtml supports Windows, macOS and Linux platforms.
  20.     //
  21.     // Dealing with errors when using DsHtml:
  22.     // - If DsHtml is not doing what you expect (e.g. rendering HTML to PDF
  23.     //   produces an invalid PDF), check the content of the string property
  24.     //   GcHtmlBrowser.ErrorLog after the call to SaveAsPdf returns,
  25.     //   it may explain why the error occurred.
  26.     //
  27.     // DsHtml uses a local copy of a Chromium-based browser.
  28.     // You can either rely on Google Chrome or Microsoft Edge browsers
  29.     // installed in the operating system, or download an instance of
  30.     // the Chromium browser to the application's local folder or some shared folder.
  31.     // If you know the custom path to an installed Chromium-based browser,
  32.     // use it instead of the above-mentioned options.
  33.     // The BrowserFetcher class can be used to install or fetch an already
  34.     // installed browser, you can then use the BrowserFetcher.GetDownloadedPath()
  35.     // to get the path to the browser. See the BrowserFetcher class for methods
  36.     // retrieving the path to Chrome or Edge executables and for other
  37.     // options and methods that help to download Chromium browser
  38.     // to a local folder if necessary.
  39.     //
  40.     // See the Util.NewHtmlBrowser() utility method used by this sample for a
  41.     // implementation example.
  42.     //
  43.     // The above notes apply to any project that uses DsHtml.
  44.     public class HelloWorldHtml
  45.     {
  46.         public int CreatePDF(Stream stream)
  47.         {
  48.             // HTML code that represents the content to render:
  49.             var html = "<!DOCTYPE html>" +
  50.                 "<html>" +
  51.                 "<head>" +
  52.                 "<style>" +
  53.                 "span.bold {" +
  54.                 "    font-weight: bold;" +
  55.                 "}" +
  56.                 "p.round {" +
  57.                 "    font: 36px arial, sans-serif;" +
  58.                 "    color: DarkSlateBlue;" +
  59.                 "    border: 4px solid SlateBlue;" +
  60.                 "    border-radius: 16px;" +
  61.                 "    padding: 3px 5px 3px 5px;" +
  62.                 "    text-shadow: 3px 2px LightSkyBlue;" +
  63.                 "}" +
  64.                 "p.note {" +
  65.                 "    font: 16px arial, sans-serif;" +
  66.                 "    color: DarkSlateBlue;" +
  67.                 "}" +
  68.                 "</style>" +
  69.                 "</head>" +
  70.                 "<body>" +
  71.                 "<p class='round'>Hello, World, from <span class='bold'>DsHtml</span>!</p>" +
  72.                 "<p class='note'>This demo shows how to use <strong>DsHtml</strong> to render HTML to PDF or images." +
  73.                 "Check out the source code of this demo for details on how to configure and use <strong>DsHtml</strong>.</p>" +
  74.                 "</body>";
  75.  
  76.             // Create a new PDF document, add a page, get graphics to draw on:
  77.             var doc = new GcPdfDocument();
  78.             var page = doc.NewPage();
  79.             var g = page.Graphics;
  80.  
  81.             try
  82.             {
  83.                 // Create an instance of GcHtmlBrowser that is used to render HTML:
  84.                 using var browser = Common.Util.NewHtmlBrowser();
  85.  
  86.                 // Render HTML.
  87.                 // The return value from DrawHtml() indicates whether anything has been rendered.
  88.                 // The output parameter 'size' returns the actual size of the rendered content.
  89.                 var ok = g.DrawHtml(browser, html, 72, 72,
  90.                     new HtmlToPdfFormat(false) { MaxPageWidth = 6.5f, MaxPageHeight = 9f },
  91.                     out SizeF size);
  92.  
  93.                 if (ok)
  94.                 {
  95.                     // If anything has been rendered, draw an extra border around the rendered content:
  96.                     var rc = new RectangleF(72 - 4, 72 - 4, size.Width + 8, size.Height + 8);
  97.                     g.DrawRoundRect(rc, 8, Color.PaleVioletRed);
  98.                 }
  99.                 else if (!string.IsNullOrEmpty(browser.ErrorLog))
  100.                 {
  101.                     // Optional diagnostics that may be useful when diagnosing browser errors.
  102.                     // Note that the error log may contain harmless information messages
  103.                     // even if there were no errors, so testing whether the error log is empty
  104.                     // should not be used as the error indicator.
  105.                     Common.Util.AddNote(browser.ErrorLog, page, 
  106.                         new RectangleF(72, 72 + size.Height + 36, page.Size.Width - 144, page.Size.Height - size.Height - 108));
  107.                 }
  108.             }
  109.             catch (Exception ex)
  110.             {
  111.                 throw new Exception($"Error:\n{ex.Message}");
  112.             }
  113.  
  114.             // Done:
  115.             doc.Save(stream);
  116.             return doc.Pages.Count;
  117.         }
  118.     }
  119. }
  120.