How do I base a style on the default style in Windows Universal apps (Win10)? - xaml

Question

In WPF, if you want to base a style on the default style of a control, you would say:
<Style TargetType="customControls:ResponsiveGridView" BasedOn="{StaticResource {x:Type GridView}}">
However, x:Type is not supported on UAP - how do I do it then? I tried the following - none works (after defining XAML as an alias for the namespace where GridView is).
<Style TargetType="customControls:ResponsiveGridView" BasedOn="{StaticResource xaml:GridView}">
<Style TargetType="customControls:ResponsiveGridView" BasedOn="xaml:GridView">
None of this works - crashes on parsing the XAML.
Any more ideas?

Answer 1

You can still use "BasedOn" for inheritance of styles.
<Page.Resources>
<Style TargetType="Button" x:Key="MyOtherStyle">
<Setter Property="Background" Value="Red"></Setter>
</Style>
<Style TargetType="Button" BasedOn="{StaticResource MyOtherStyle}" >
<Setter Value="Green" Property="Foreground"></Setter>
</Style>
</Page.Resources>
Just define the resources like above. They'll be applied for every button on the page.
<Button Content="Hello"></Button>
To base on a default style of a control, you don't use "BasedOn". You implicitly base on the default style of a control by specifying the TargetType in the style.
To be more precise for your special case:
If you want to use an (implicit) style for your custom control that is based on a default style of a built-in control do the follwing:
Create a custom style that targets the built-in control type. Like this:
<Page.Resources>
<Style TargetType="Grid" x:Key="MyStyle1" >
<Setter Property="Background" Value="Green"></Setter>
</Style>
...
Then add another style that targets your custom control type an is based on your custom style for the built-in control. Like this:
...
<Style TargetType="local:MyCustomGrid" BasedOn="{StaticResource MyStyle1}">
<Setter Property="BorderBrush" Value="Black"></Setter>
<Setter Property="BorderThickness" Value="4"></Setter>
</Style>
</Page.Resources>
All your MyCustomGrid controls will implicitly get the style which is based on the default style.
All standard Grids will keep their default style, because they won't get the style implicitly, because you specified the x:key in the first style and therefore have to explicitly set the style of the grids. Does this clarify?