Theme support in Windows Presentation Foundation
Neil Kronlage provided this answer:
The WPF theme engine will switch styles automatically for you if you place them in separate
ResourceDictionaryXAML files compiled in your application.
The files need to be named
for example, these are the themes that Microsoft produces:
The case for classic is slightly different:
Windows Presentation Foundation does not provide an event when the theme changes. If you need to go beyond what is provided by styles in a resource dictionary, you will need to listen to the WM_THEMECHANGE message in a window hook.