NumberBox does not respect ThemeManager theme

[dostjh]

I implemented NumberBox in my application that is set up to work in Dark Mode. However, NumberBox did not respect the theme.

Specifying ThemeManager.RequestedTheme on the control itself can be used as a workaround.

Bug
<ui:NumberBox Header="Clients to start" Value="{Binding NumberOfClientsToStart, Mode=TwoWay}" InputScope="Number" SpinButtonPlacementMode="Inline" Text="Clients to start"/>

Workaround
<ui:NumberBox Header="Clients to start" Value="{Binding NumberOfClientsToStart, Mode=TwoWay}" InputScope="Number" SpinButtonPlacementMode="Inline" Text="Clients to start" ui:ThemeManager.RequestedTheme="Dark"/>

[TomHedwig]

I met the same problem. @dostjh
Additionally, VS would prompt a binding error like that:

Severity	Count	Data Context	Binding Path	Target	Target Type	Description
Error	1	null	Fill	GeometryDrawing.Brush	Brush	Cannot find governing FrameworkElement or FrameworkContentElement for target element.

[dostjh]

This appears to also happen for TextBlock elements.