--- title: "How to: Use System Fonts Keys" ms.date: "03/30/2017" helpviewer_keywords: - "resource keys [WPF], SystemFonts class" ms.assetid: 036ebea7-5677-4f60-8ba4-56c9f9d9b8bd --- # How to: Use System Fonts Keys System resources expose a number of system metrics as resources to help developers create visuals that are consistent with system settings. is a class that contains both system font values and system font resources that bind to the values—for example, and . System font metrics can be used as either static or dynamic resources. Use a dynamic resource if you want the font metric to update automatically while the application runs; otherwise use a static resource. > [!NOTE] > Dynamic resources have the keyword *Key* appended to the property name. The following example shows how to access and use system font dynamic resources to style or customize a button. This [!INCLUDE[TLA2#tla_xaml](../../../includes/tla2sharptla-xaml-md.md)] example creates a button style that assigns values to a button. ## Example [!code-xaml[SystemRes_snip#FontDynamicResources](~/samples/snippets/csharp/VS_Snippets_Wpf/SystemRes_snip/CSharp/MyApp.xaml#fontdynamicresources)] ## See also - [Paint an Area with a System Brush](../graphics-multimedia/how-to-paint-an-area-with-a-system-brush.md) - [Use SystemParameters](how-to-use-systemparameters.md) - [Use SystemFonts](how-to-use-systemfonts.md)