Document Viewer API

We are pleased to announce the release of GroupDocs.Viewer for .NET 18.10. The latest version allows setting the list of the fonts that should be excluded from the output HTML to decrease the size of the output files. Furthermore, the inclusion of 5 improvements and 6 bug fixes have made the API more promising. Below is the list of new features, improvements, and fixes added in v18.10.

Features Introduced

Setting List of the Fonts to be Excluded

Adding fonts into HTML ensures that the text from the original document will appear similar in HTML, regardless of whether fonts are installed on the viewer’s device or not. At the same time, this improvement comes with the cost of the increased size of the output file.Therefore, GroupDocs.Viewer API provides a new setting - HtmlOptions.ExcludeFontsList, that prevents adding specific fonts (that are commonly available on most of the devices). The code sample below shows how to prevent adding fonts into output HTML.

// Setup GroupDocs.Viewer config
ViewerConfig config = new ViewerConfig();
config.StoragePath = @"C:\storage";
// Create html handler
ViewerHtmlHandler htmlHandler = new ViewerHtmlHandler(config);
string guid = "presentation.pptx";
HtmlOptions options = new HtmlOptions();
options.ExcludeFontsList.Add("Times New Roman");
List pages = htmlHandler.GetPages(guid, options);
foreach (PageHtml page in pages)
    Console.WriteLine("Page number: {0}", page.PageNumber);
    Console.WriteLine("Html content: {0}", page.HtmlContent);

For more details on this feature, please visit this documentation article.


We have included following improvements in version 18.10:

  • Prevent showing items beyond StartDate and EndDate options when rendering MS Project documents
  • Release internal resources for methods which accept URL
  • GetDocumentInfo method’s page number depending on the type of ViewerHandler
  • Prevent setting malicious values for HtmlResourcePrefix
  • Improve setting PageSize and TimeScale for MS Project documents by default

Bug Fixes

Following issues are fixed in version 18.10 of GroupDocs.Viewer for .NET.

  • “Specified watermark font not found” exception when calling GetPdfFile method
  • OutlookOptions.MaxItemsInFolder option not working properly for rendering into image and PDF
  • Incorrect rendering of PDF document into HTML
  • Duplicate link tag when rendering text documents with external resources
  • Exception when rendering PDF document as HTML
  • Images are missing when rendering PDF document into HTML or Image

Related Links and Resources

We have a few channels and resources for you to download, learn, try and get technical support on GroupDocs.Viewer.


As always, if you have any questions or suggestions, feel free to write on our forum.