Hi hcpizzi Thanks for the answer, but I still have an question. In my first post, I show this action: <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Defaults.xaml" /> </ResourceDiction...

Hi, I try to use several resource libraries <ResourceDictionary.MergedDictionaries> <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.Wpf;component/Themes/MaterialDesignTheme.Light.xaml" /> <ResourceDictionary Source="pack://application:,,,/MaterialDesignThemes.W...