ThemeMode style not applying to TextBlock in a Page

[safreed-msft]

Description

I'm trying out the new fluent ui theming in .NET 9 but hit an issue where the theme styles aren't inherited by pages. (update: Seems to only be for TextBlocks?)

Reproduction Steps

1. Create new WPF project with .NET 9
2. Set ThemeMode="Dark" in App.xaml
3. Create a Page with just a TextBlock
4. In MainWindow.xaml, add a Frame and navigate to the created Page

Expected behavior

Page's textblock is styled appropriately (light foreground color since background is dark)

Actual behavior

Text foreground is dark

Regression?

No response

Known Workarounds

No response

Impact

No response

Configuration

No response

Other information

No response

[dipeshmsft]

Hey @safreed-msft, yes this is a known issue with Page, one simple workaround for this is to add the Foreground="{DynamicResource TextFillColorPrimaryBrush}" as an attribute of Page tag.

[safreed-msft]

Thanks for the confirmation @dipeshmsft! I'm looking forward to these issues being resolved to bring a much-needed good default theme to WPF!

[dipeshmsft]

@safreed-msft, this is more of a limitation of implicit styles. Implicit styles are not loaded for derived types. We did some workarounds for Window and put it in WPF for now. But this was difficult to do for Page, hence we left it this way. The real solution will be that we load the Fluent styles in default style and we are working on that now.

Given this, if you are okay, can I go ahead and close this issue.

[safreed-msft]

I see, thanks for the explanation. Yes this issue can be closed.