Agreed this an important Uno feature. There's a starting point here https://github.com/unoplatform/uno/blob/master/doc/articles/using-uno-ui.md#using-styles addressing Uno 3.0+ support for native styles.

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Excellent!

From the referenced documentation I'm not quite sure whether I will be able to render UWP style for particular pages only, or even for particular elements only.

This is my use case:

In general, I would prefer to render native controls throughout my app. For one, I presume they will be rendered faster; and for two, the user is acquainted to this controls style and will prefer this style.

Then, there may be a "sophisticated" page in my app where I want all controls to adhere to my fancy custom UWP style. Or there may be only a single grid in a page where I want my fancy styles to apply.

Can this be done, too? Is there something like a style attribute or style element I can add to XAML elements to switch mode?

Something like this:

<NativePresenterArea>
  <ToggleSwitch />
</NativePresenterArea>

<!-- or -->

<UwpPresenterArea>
  <ToggleSwitch />
</UwpPresenterArea>

<!-- or -->

<NativePresenterArea Mode="Native">
  <ToggleSwitch />
</NativePresenterArea>
<NativePresenterArea Mode="UWP">
  <ToggleSwitch />
</NativePresenterArea>

Is this the xamarin:IsNativeStyle attribute mentioned in the documentation?

Perhaps my question is stupid. I'm new to UWP, please forgive my ignorance if it is.

This is actually straightforward to do for single elements. You can assign a StaticResource (a resource, such as a style, a brush, or control template, defined elsewhere in Xaml) to the Style property, and Uno's native and UWP styles all have associated StaticResources following the naming convention in the link. So in your example it would be:

<NativePresenterArea>
  <ToggleSwitch not_win:Style="{StaticResource NativeDefaultToggleSwitch}"/>
</NativePresenterArea>

<!-- or -->

<UwpPresenterArea>
  <ToggleSwitch not_win:Style="{StaticResource XamlDefaultToggleSwitch}"/>
</UwpPresenterArea>

See here for an explanation of the not_win prefix.

There's no out-of-the-box way to say 'all controls within this page should have UWP/native styling' at the moment.

Fascinating! Thanks a lot for this very helpful information!

Would you suggest to keep this issue open as a reminder for adding your valuable information to the FAQ? Or should this issue rather be closed?

Let's keep it open, it's a valid documentation request and the info does belong in the docs, not just in an issue comment ;)

@davidjohnoliver For now the info could be added under articles into a new howto file right ?

@agneszitte-nventive Indeed :) Something like using-native-styles.md in that folder.

Note for contributors: As mentioned in an earlier comment, expanding the material here would be a good basis.

There are also a couple more configuration methods added recently which can be documented.