This is a UWP class library to inject HTML into a RichTextBlock easily

Usage:

1. In a XAML file, declare the namespace:

xmlns:html="using:XAMLHtml" 

2. In RichTextBlock controls, set or databind the Html property:

<RichTextBlock html:Properties.Html="{Binding ...}"/>

or

<RichTextBlock>
    <html:Properties.Html>
        <![CDATA[
            <p>This is a list:</p>
            <ul>
                <li>Item 1</li>
                <li>Item 2</li>
                <li>Item 3</li>
            </ul>
		]]>
	</html:Properties.Html>
</RichTextBlock>

h1, h2 and h3 tag can apply a custom format with the following code:

HtmlProperties.H2SpanFactory = () => new Span
{
    FontSize = 13.71,
    FontWeight = FontWeights.Light
};

To set a max width/height of <img> tags:

HtmlProperties.ImageMaxPixelWidth = 500;
HtmlProperties.ImageMaxPixelHeight = 500;

All credits to https://blogs.msdn.microsoft.com/tess/2013/05/13/displaying-html-content-in-a-richtextblock/