Controls created with XamlReader.Parse don't inherit styles

Question

In my application the user can type in HTML, which then gets converted to XAML. I then parse the XAML using the XamlReader.Parse method and add it to a FlowDocument.

For example, let's suppose I have the XAML for a paragraph stored in a string, and then I parse it and add it to a FlowDocument like so:

var xaml = @"<Paragraph Style=""{DynamicResource Big}"" xmlns=""http://schemas.microsoft.com/winfx/2006/xaml/presentation"">My paragraph</Paragraph>";
var paragraph = (Paragraph)XamlReader.Parse(xaml);
MyDocument.Blocks.Add(paragraph);

Notice that the paragraph has a Style specified. That Style is defined in the FlowDocument's Resources.

<RichTextBox>
    <FlowDocument x:Name="MyDocument">
        <FlowDocument.Resources>
            <Style TargetType="{x:Type Paragraph}">
                <Setter Property="Foreground"
                        Value="Red" />
            </Style>

            <Style TargetType="{x:Type Paragraph}"
                   BasedOn="{StaticResource {x:Type Paragraph}}"
                   x:Key="Big">
                <Setter Property="FontSize"
                        Value="24" />
            </Style>
        </FlowDocument.Resources>
    </FlowDocument>
</RichTextBox>

You can see that I've defined two styles. The first is an implicit style, and the second extends the first using the BasedOn attribute. When I dynamically add the Paragraph to the FlowDocument it does pick up the 'Big' Style. However, there's a caveat, it does not pick up the Red Foreground color of the implicit style. How can I make it pick up both?

This only seems to be a problem when I parse the XAML. If I just instantiate a new Paragraph object and add it to the FlowDocument, it does indeed pick up both styles.

Controls created with XamlReader.Parse don't inherit styles

0 Answers0