Silverlight 4 - Mousewheel stops scrolling ScrollViewer when over contained RichTextBox

Question

I have a Silverlight 4 out-of-browser application with a ScrollViewer that has several RichTextBoxes inside. The RichTextBoxes are only used for displaying text, and are never edited and never scroll.

However when the mouse is hovering over a RichTextBox the mousewheel event seems to not reach the ScrollViewer. Is there any way to overcome this limitation?

Answer 1

The reason a readonly RichTextBox doesn't scroll is because the default template for RichTextBox uses a ScrollViewer instead of a ContentControl. So to solve the problem, you need to create your own template for RichTextBox.

What I did was to create a copy of the RichTextBox template in Blend, and strip it down for the readonly case. This removes about 90% of the template. The following style/template remains:

<Style TargetType="c:RichTextBlock">
    <Setter Property="IsReadOnly" Value="True" />
    <Setter Property="Background" Value="Transparent"/>
    <Setter Property="Template">
        <Setter.Value>
            <ControlTemplate>
                <Grid x:Name="RootElement">
                    <Border x:Name="Border" CornerRadius="0"
                            BorderBrush="{TemplateBinding BorderBrush}"
                            BorderThickness="{TemplateBinding BorderThickness}"
                            Background="{TemplateBinding Background}"
                            Padding="{TemplateBinding Padding}"
                        >
                        <ContentControl x:Name="ContentElement" IsTabStop="False" />
                    </Border>
                </Grid>
            </ControlTemplate>
        </Setter.Value>
    </Setter>
</Style>

Use this style/template for your readonly RichTextBox'es, and you should be good to go.

Goood luck,
Jim McCurdy
Face to Face Software and YinYangMoney