The WPF RichTextBox control, a WYSIWYG rich text editor, provides all the common word-processing features including editing text, formatting contents, resizing images and tables, finding and replacing text, spell checking, adding comments, printing, and importing and exporting Word documents. Here Mudassar Ahmed Khan has explained with example and attached sample code, how to use and integrate the ASP.Net AJAX Control Toolkit HtmlEditorExtender Rich Text Editor in a website. TAGs: ASP.Net, Rich Text Editor, AJAX Control Toolkit, HtmlEditorExtender Description. This sample used Code mirror plugins helps to highlight the HTML content and when changes happens in code view, the same has been reflected in preview mode. The editor's toolbar contains commands to format the content. The toolbar consists of: Lists - NumberFormat list and BulletFormat list types. Rich Text is a field type that enables authors to create rich text content, similar to traditional "What you see is what you get" (wysiwyg) editors. The key difference here is that the Contentful Rich Text Field (RTF) response is returned as pure JSON rather than HTML. It offers common text formatting options such as paragraphs, lists and Method 1: Adding SfRichTextEditor reference from nuget.org. Syncfusion Xamarin components are available in nuget.org. To add Rich Text Editor to your project, open the NuGet package manager in Visual Studio, search for Syncfusion.Xamarin.SfRichTextEditor and then install it. NOTE.