Question

My intent is to override phone theme. By default page markup has following code:

<phone:PhoneApplicationPage 
FontFamily="{StaticResource PhoneFontFamilyNormal}"
FontSize="{StaticResource PhoneFontSizeNormal}"
Foreground="{StaticResource PhoneForegroundBrush}"

I replace it with a style reference:

<phone:PhoneApplicationPage 
Style="{StaticResource stylePage}"    

Style is defined in app resources like this:

<Application.Resources>
    <Style x:Key="stylePage" TargetType="phone:PhoneApplicationPage">
        <Setter Property="Background" Value="White" />
        <Setter Property="Foreground" Value="DeepSkyBlue" />
        <Setter Property="FontFamily" Value="Arial" />
    </Style>
</Application.Resources>

But background is still black, and font is white. Debugger shows that the values were applied.
If I set VisualRoot Grid’s background, it’s applied, but I want to set fontfamily and foreground values to be used by all my controls by default. Is it possible?

Answer 1

According to this msdn article – only the following properties are inherited in the visual tree in Silverlight: FontFamily, FontSize, FontStretch, FontStyle, FontWeight, and Foreground. Normally – dependency properties are not inherited in Silverlight (they often are in WPF). This is likely why these are not mentioned in the Silverlight MSDN article on dependency property value precedence, but the WPF version of the article mentions inherited value as lower priority than the local value or style setters. Your solution in fact works to some degree, but by default – most controls have font properties set by their style – Buttons by their default style, TextBlocks in page templates use PhoneTextNormalStyle or PhoneTextTitle1Style. If you remove the XML attributes setting the style of your TextBlocks – your application-wide font properties will apply to the TextBlocks.

Background dependency property unfortunately is not inherited, so your background will remain as is.

Your application-wide properties will not work on controls more complex than TextBlocks – like Buttons, since the default style of Buttons and other controls defines the style of TextBlocks explicitly using appropriate system styles.

I would say you should create your own resource dictionaries with styles of your controls and apply these to your controls manually, otherwise – you would need to write some code to automatically replace these properties at run time.