To do that, all you have to do is change the Expander
's template to use Surface controls instead of the regular controls.
The Expander
's default template can be found at http://msdn.microsoft.com/en-us/library/ms753296.aspx.
All you need to change is the ToggleButton:
<ToggleButton OverridesDefaultStyle="True"
Template="{StaticResource ExpanderToggleButton}"
IsChecked="{Binding IsExpanded, Mode=TwoWay,
RelativeSource={RelativeSource TemplatedParent}}">
changes to
<s:SurfaceToggleButton OverridesDefaultStyle="True"
Template="{StaticResource ExpanderToggleButton}"
IsChecked="{Binding IsExpanded, Mode=TwoWay,
RelativeSource={RelativeSource TemplatedParent}}">
(closing tags omitted)
This assumes s
is bound to the Surface XML Namespace:
xmlns:s="http://schemas.microsoft.com/surface/2008"