HelloWorldHtml.cs 
  1. //
  2. // This code is part of Document Solutions for Imaging 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.Drawing;
  9. using GrapeCity.Documents.Imaging;
  10. using GrapeCity.Documents.Text;
  11. using GrapeCity.Documents.Html;
  12.  
  13. namespace DsImagingWeb.Demos
  14. {
  15.     // This sample shows how to render a hard-coded HTML string.
  16.     //
  17.     // Adding DsHtml to your projects:
  18.     // - Public classes and extension methods that enable rendering HTML
  19.     //   are provided by the GrapeCity.Documents.Html (DsHtml) package.
  20.     // - DsHtml supports Windows, macOS and Linux platforms.
  21.     //
  22.     // Dealing with errors when using DsHtml:
  23.     // - If DsHtml is not doing what you expect (e.g. rendering HTML to PDF
  24.     //   produces an invalid PDF), check the content of the string property
  25.     //   DsHtmlBrowser.ErrorLog after the call to SaveAsPdf returns,
  26.     //   it may explain why the error occurred.
  27.     //
  28.     // DsHtml uses a local copy of a Chromium-based browser.
  29.     // You can either rely on Google Chrome or Microsoft Edge browsers
  30.     // installed in the operating system, or download an instance of
  31.     // Chromium browser to the application's local folder or some shared folder.
  32.     // If you know the custom path to an installed Chromium-based browser,
  33.     // use it instead of the above-mentioned options.
  34.     // The BrowserFetcher class can be used to install or fetch an already
  35.     // installed browser, you can then use the BrowserFetcher.GetDownloadedPath()
  36.     // to get the path to the browser. See the BrowserFetcher class for methods
  37.     // retrieving the path to Chrome or Edge executables and for other
  38.     // options and methods that help to download Chromium browser
  39.     // to a local folder if necessary.
  40.     //
  41.     // See the Util.NewHtmlBrowser() utility method used by this sample for a
  42.     // implementation example.
  43.     //
  44.     // The above notes apply to any project that uses DsHtml.
  45.     public class HelloWorldHtml
  46.     {
  47.         public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)
  48.         {
  49.             // HTML code that represents the content to render:
  50.             var html = "<!DOCTYPE html>" +
  51.                 "<html>" +
  52.                 "<head>" +
  53.                 "<style>" +
  54.                 "span.bold {" +
  55.                     "font-weight: bold;" +
  56.                 "}" +
  57.                 "p.round {" +
  58.                     "font: 36px arial, sans-serif;" +
  59.                     "color: DarkSlateBlue;" +
  60.                     "border: 4px solid SlateBlue;" +
  61.                     "border-radius: 16px;" +
  62.                     "padding: 3px 5px 3px 5px;" +
  63.                     "text-shadow: 3px 2px LightSkyBlue;" +
  64.                 "}" +
  65.                 "</style>" +
  66.                 "</head>" +
  67.                 "<body>" +
  68.                 "<p class='round'>Hello, World, from <span class='bold'>DsHtml</span>!</p>" +
  69.                 "</body>" +
  70.                 "</html>";
  71.  
  72.             var margin = dpi;
  73.             var bmp = new GcBitmap(pixelSize.Width, pixelSize.Height, true, dpi, dpi);
  74.             using (var g = bmp.CreateGraphics(Color.White))
  75.             {
  76.                 // Create an instance of GcHtmlBrowser that is used to render HTML:
  77.                 using var browser = Common.Util.NewHtmlBrowser();
  78.  
  79.                 // Render HTML.
  80.                 // The return value from DrawHtml() indicates whether anything has been rendered.
  81.                 // The output parameter 'size' returns the actual size of the rendered content.
  82.                 var ok = g.DrawHtml(browser, html,
  83.                     margin, margin,
  84.                     new HtmlToImageFormat(true)
  85.                     {
  86.                         WindowSize = new Size((int)(pixelSize.Height - margin * 2), (int)(pixelSize.Width - margin * 2))
  87.                     },
  88.                     out SizeF size);
  89.  
  90.                 // If anything has been rendered, draw an extra border around the rendered content:
  91.                 if (ok)
  92.                 {
  93.                     var rc = new RectangleF(margin - 4, margin - 4, size.Width + 8, size.Height + 8);
  94.                     g.DrawRoundRect(rc, 8, Color.PaleVioletRed);
  95.                 }
  96.                 else if (!string.IsNullOrEmpty(browser.ErrorLog))
  97.                 {
  98.                     // Optional diagnostics that may be useful when diagnosing browser errors.
  99.                     // Note that the error log may contain harmless information messages
  100.                     // even if there were no errors, so testing whether the error log is empty
  101.                     // should not be used as the error indicator.
  102.                     Common.Util.AddNote(browser.ErrorLog, g,
  103.                         new RectangleF(margin, margin + size.Height + 36, bmp.PixelWidth - margin * 2, bmp.PixelHeight - size.Height - margin * 2));
  104.                 }
  105.             }
  106.             return bmp;
  107.         }
  108.     }
  109. }
  110.