This documentation is archived and is not being maintained.

How to: Use SystemFonts

This example shows how to use the static resources of the SystemFonts class in order to style or customize a button.

System resources expose several system-determined values as both resources and properties in order to help you create visuals that are consistent with system settings. SystemFonts is a class that contains both system font values as static properties, and properties that reference resource keys that can be used to access those values dynamically at run time. For example, CaptionFontFamily is a SystemFonts value, and CaptionFontFamilyKey is a corresponding resource key.

In XAML, you can use the members of SystemFonts as either static properties or dynamic resource references (with the static property value as the key). Use a dynamic resource reference if you want the font metric to automatically update while the application runs; otherwise, use a static value reference.


The resource keys have the suffix "Key" appended to the property name.

The following example shows how to access and use the properties of SystemFonts as static values in order to style or customize a button. This markup example assigns SystemFonts values to a button.

<Button Margin="10, 10, 5, 5" Grid.Column="0" Grid.Row="3"      
     FontSize="{x:Static SystemFonts.IconFontSize}"
     FontWeight="{x:Static SystemFonts.MessageFontWeight}"
     FontFamily="{x:Static SystemFonts.CaptionFontFamily}">

To use the values of SystemFonts in code, you do not have to use either a static value or a dynamic resource reference. Instead, use the non-key properties of the SystemFonts class. Although the non-key properties are apparently defined as static properties, the run-time behavior of WPF as hosted by the system will reevaluate the properties in real time and will properly account for user-driven changes to system values. The following example shows how to specify the font settings of a button.

Dim btn As New Button()
btn.Content = "SystemFonts"
btn.Background = SystemColors.ControlDarkDarkBrush
btn.FontSize = SystemFonts.IconFontSize
btn.FontWeight = SystemFonts.MessageFontWeight
btn.FontFamily = SystemFonts.CaptionFontFamily