How to use the new DayNight Theme?

Question

Starting to get my hands into that new update to the Google Support Library and I want to implement the Theme.AppCompat.DayNight into my app.
The problem I

Answer 1

You can use the night resource qualifier folder.
In this way you can define colors and the other resources for the dark (night) and for the light theme (day).

Qualifiers:
night: Night time
notnight: Day time

In order to support the dark theme with a Material Components Theme use:

<style name="Theme.MyApp" parent="Theme.MaterialComponents.DayNight">
    <!-- ... -->
</style>

With an AppCompat theme:

  <style name="AppTheme" parent="Theme.AppCompat.DayNight">
      <item name="colorPrimary">@color/primary</item>
   </style>

Then define in your app theme the references color resources, and override the value in the values-night directory if needed:

Example: res\values\colors.xml:

   <color name="colorPrimary">.....</color>

In res\values-night\colors.xml folders define the same color:

   <color name="colorPrimary">.....</color>