Xamarin form app restarts when theme is changed.

Question

Steps:

1. Xamarin form app is installed on Android.
2. Change the theme in Settings app.
3. From multitask go back to the form app
4. The app will restarts.

Expected : The dark theme should be applied without the app restart.

Please let us know if any other workarounds.

Answer 1

Hello,​

Welcome to our Microsoft Q&A platform!

The dark theme should be applied without the app restart.

To respond to theme changes on Android, please make sure you've included the ConfigChanges.UiMode flag in the Activity attribute of your MainActivity class as below.

   [Activity(Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = =ConfigChanges.UiMode ...)]  
   public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity  
   {  
       ...  
   }  

For more details, you could refer to this doc: https://developer.android.com/guide/topics/resources/runtime-changes

Best Regards,

Jarvan Zhang

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