Modifiche al comportamento: tutte le app

La piattaforma Android 16 include modifiche al comportamento che potrebbero influire sulla tua app. Le seguenti modifiche al comportamento si applicano a tutte le app quando vengono eseguite su Android 16, indipendentemente da targetSdkVersion. Dovresti testare l'app e poi modificarla come necessario per supportare queste modifiche, se applicabili.

Assicurati di esaminare anche l'elenco delle modifiche del comportamento che interessano solo le app con target Android 16.

Funzionalità di base

Android 16 (livello API 36) include le seguenti modifiche che modificano o ampliano varie funzionalità di base del sistema Android.

Ottimizzazioni delle quote di JobScheduler

Starting in Android 16, we're adjusting regular and expedited job execution runtime quota based on the following factors:

  • Which app standby bucket the application is in: in Android 16, active standby buckets will start being enforced by a generous runtime quota.
  • If the job starts execution while the app is in a top state: in Android 16, Jobs started while the app is visible to the user and continues after the app becomes invisible, will adhere to the job runtime quota.
  • If the job is executing while running a Foreground Service: in Android 16, jobs that are executing while concurrently with a foreground service will adhere to the job runtime quota. If you're leveraging jobs for user initiated data transfer, consider using user initiated data transfer jobs instead.

This change impacts tasks scheduled using WorkManager, JobScheduler, and DownloadManager. To debug why a job was stopped, we recommend logging why your job was stopped by calling WorkInfo.getStopReason() (for JobScheduler jobs, call JobParameters.getStopReason()).

For more information on battery-optimal best practices, refer to guidance on optimize battery use for task scheduling APIs.

We also recommend leveraging the new JobScheduler#getPendingJobReasonsHistory API introduced in Android 16 to understand why a job has not executed.

Testing

To test your app's behavior, you can enable override of certain job quota optimizations as long as the app is running on an Android 16 device.

To disable enforcement of "top state will adhere to job runtime quota", run the following adb command:

adb shell am compat enable OVERRIDE_QUOTA_ENFORCEMENT_TO_TOP_STARTED_JOBS APP_PACKAGE_NAME

To disable enforcement of "jobs that are executing while concurrently with a foreground service will adhere to the job runtime quota", run the following adb command:

adb shell am compat enable OVERRIDE_QUOTA_ENFORCEMENT_TO_FGS_JOBS APP_PACKAGE_NAME

To test certain app standby bucket behavior, you can set the app standby bucket of your app using the following adb command:

adb shell am set-standby-bucket APP_PACKAGE_NAME active|working_set|frequent|rare|restricted

To understand the app standby bucket your app is in, you can get the app standby bucket of your app using the following adb command:

adb shell am get-standby-bucket APP_PACKAGE_NAME

Motivo dell'interruzione dei job vuoti abbandonati

An abandoned job occurs when the JobParameters object associated with the job has been garbage collected, but JobService#jobFinished(JobParameters, boolean) has not been called to signal job completion. This indicates that the job may be running and being rescheduled without the app's awareness.

Apps that rely on JobScheduler, don't maintain a strong reference to the JobParameters object, and timeout will now be granted the new job stop reason STOP_REASON_TIMEOUT_ABANDONED, instead of STOP_REASON_TIMEOUT.

If there are frequent occurrences of the new abandoned stop reason, the system will take mitigation steps to reduce job frequency.

Apps should use the new stop reason to detect and reduce abandoned jobs.

If you're using WorkManager, AsyncTask, or DownloadManager, you aren't impacted because these APIs manage the job lifecycle on your app's behalf.

Ritiro completo di JobInfo#setImportantWhileForeground

The JobInfo.Builder#setImportantWhileForeground(boolean) method indicates the importance of a job while the scheduling app is in the foreground or when temporarily exempted from background restrictions.

This method has been deprecated since Android 12 (API level 31). Starting in Android 16, it no longer functions effectively and calling this method will be ignored.

This removal of functionality also applies to JobInfo#isImportantWhileForeground(). Starting in Android 16, if the method is called, the method returns false.

L'ambito della priorità di trasmissione ordinata non è più globale

Android apps are allowed to define priorities on broadcast receivers to control the order in which the receivers receive and process the broadcast. For manifest-declared receivers, apps can use the android:priority attribute to define the priority and for context-registered receivers, apps can use the IntentFilter#setPriority() API to define the priority. When a broadcast is sent, the system delivers it to receivers in order of their priority, from highest to lowest.

In Android 16, broadcast delivery order using the android:priority attribute or IntentFilter#setPriority() across different processes will not be guaranteed. Broadcast priorities will only be respected within the same application process rather than across all processes.

Also, broadcast priorities will be automatically confined to the range (SYSTEM_LOW_PRIORITY + 1, SYSTEM_HIGH_PRIORITY - 1). Only system components will be allowed to set SYSTEM_LOW_PRIORITY, SYSTEM_HIGH_PRIORITY as broadcast priority.

Your app might be impacted if it does either of the following:

  1. Your application has declared multiple processes with the same broadcast intent, and has expectations around receiving those intents in a certain order based on the priority.
  2. Your application process interacts with other processes and has expectations around receiving a broadcast intent in a certain order.

If the processes need to coordinate with each other, they should communicate using other coordination channels.

Modifiche interne all'ART

Android 16 includes the latest updates to the Android Runtime (ART) that improve the Android Runtime's (ART's) performance and provide support for additional Java features. Through Google Play System updates, these improvements are also available to over a billion devices running Android 12 (API level 31) and higher.

As these changes are released, libraries and app code that rely on internal structures of ART might not work correctly on devices running Android 16, along with earlier Android versions that update the ART module through Google Play system updates.

Relying on internal structures (such as non-SDK interfaces) can always lead to compatibility problems, but it's particularly important to avoid relying on code (or libraries containing code) that leverages internal ART structures, since ART changes aren't tied to the platform version the device is running on and they go out to over a billion devices through Google Play system updates.

All developers should check whether their app is impacted by testing their apps thoroughly on Android 16. In addition, check the known issues to see if your app depends on any libraries that we've identified that rely on internal ART structures. If you do have app code or library dependencies that are affected, seek public API alternatives whenever possible and request public APIs for new use cases by creating a feature request in our issue tracker.

Modalità di compatibilità con le dimensioni pagina di 16 kB

Android 15 introduced support for 16 KB memory pages to optimize performance of the platform. Android 16 adds a compatibility mode, allowing some apps built for 4 KB memory pages to run on a device configured for 16 KB memory pages.

When your app is running on a device with Android 16 or higher, if Android detects that your app has 4 KB aligned memory pages, it automatically uses compatibility mode and display a notification dialog to the user. Setting the android:pageSizeCompat property in the AndroidManifest.xml to enable the backwards compatibility mode will prevent the display of the dialog when your app launches. To use the android:pageSizeCompat property, compile your app using the Android 16 SDK.

For best performance, reliability, and stability, your app should still be 16 KB aligned. Check out our recent blog post on updating your apps to support 16 KB memory pages for more details.

The compatibility mode dialog that displays when the system detects that a 4 KB-aligned app could run more optimally if 16 KB aligned.

Esperienza utente e interfaccia utente di sistema

Android 16 (livello API 36) include le seguenti modifiche volte a creare un'esperienza utente più coerente e intuitiva.

Ritiro degli annunci di accessibilità che causano interruzioni

Android 16 deprecates accessibility announcements, characterized by the use of announceForAccessibility or the dispatch of TYPE_ANNOUNCEMENT accessibility events. These can create inconsistent user experiences for users of TalkBack and Android's screen reader, and alternatives better serve a broader range of user needs across a variety of Android's assistive technologies.

Examples of alternatives:

The reference documentation for the deprecated announceForAccessibility API includes more details about suggested alternatives.

Supporto della navigazione con tre pulsanti

Android 16 brings predictive back support to the 3-button navigation for apps that have properly migrated to predictive back. Long-pressing the back button initiates a predictive back animation, giving you a preview of where the back swipe takes you.

This behavior applies across all areas of the system that support predictive back animations, including the system animations (back-to-home, cross-task, and cross-activity).

The predictive back animations in 3-button navigation mode.

Fattori di forma del dispositivo

Android 16 (livello API 36) include le seguenti modifiche per le app quando vengono proiettate sui display dai proprietari di dispositivi virtuali.

Sostituzioni del proprietario del dispositivo virtuale

Un proprietario di dispositivo virtuale è un'app attendibile o con privilegi che crea e gestisce un dispositivo virtuale. I proprietari di dispositivi virtuali eseguono app su un dispositivo virtuale e poi le proiettano sul display di un dispositivo remoto, ad esempio un personal computer, un dispositivo di realtà virtuale o un sistema di infotainment per auto. Il proprietario del dispositivo virtuale si trova su un dispositivo locale, ad esempio un cellulare.

Il proprietario del dispositivo virtuale sullo smartphone crea un dispositivo virtuale che proietta l'app sul display remoto.

Sostituzioni per app

Sui dispositivi con Android 16 (livello API 36), i proprietari di dispositivi virtuali possono eseguire l'override delle impostazioni delle app su determinati dispositivi virtuali gestiti da loro. Ad esempio, per migliorare il layout delle app, un proprietario di un dispositivo virtuale può ignorare le limitazioni relative a orientamento, formato e ridimensionamento durante la proiezione delle app su un display esterno.

Modifiche che provocano un errore comuni

Il comportamento di Android 16 potrebbe influire sull'interfaccia utente della tua app su fattori di forma con schermi di grandi dimensioni, come display dell'auto o Chromebook, in particolare sui layout progettati per schermi di piccole dimensioni in orientamento verticale. Per scoprire come rendere la tua app adattabile a tutti i fattori di forma del dispositivo, consulta Informazioni sui layout adattabili.

Riferimenti

Streaming di app complementari

Sicurezza

Android 16 (livello API 36) include modifiche che promuovono la sicurezza del sistema per contribuire a proteggere app e utenti da app dannose.

Maggiore sicurezza contro gli attacchi di reindirizzamento degli intent

Android 16 fornisce sicurezza predefinita contro gli attacchi di reindirizzamento Intent generici, con requisiti minimi di compatibilità e modifiche richieste agli sviluppatori.

Stiamo introducendo soluzioni di rafforzamento della sicurezza predefinite per gli exploit di Intent ridirezione. Nella maggior parte dei casi, le app che utilizzano gli intent normalmente non riscontrano problemi di compatibilità. Abbiamo raccolto le metriche durante il nostro processo di sviluppo per monitorare le app che potrebbero riscontrare interruzioni.

Il reindirizzamento di intent in Android si verifica quando un malintenzionato può controllare parzialmente o completamente i contenuti di un intent utilizzato per avviare un nuovo componente nel contesto di un'app vulnerabile, mentre l'app vittima avvia un intent di livello secondario non attendibile in un campo extra di un intent ("di primo livello"). Ciò può portare all'app malintenzionata a lanciare componenti privati nel contesto dell'app vittima, attivare azioni privilegiate o ottenere l'accesso tramite URI a dati sensibili, potenzialmente conducendo a furto di dati ed esecuzione di codice arbitrario.

Disattivare la gestione del reindirizzamento intent

Android 16 introduce una nuova API che consente alle app di disattivare le protezioni di sicurezza al momento del lancio. Ciò potrebbe essere necessario in casi specifici in cui il comportamento di sicurezza predefinito interferisce con casi d'uso legittimi delle app.

Per le applicazioni compilate con l'SDK Android 16 (livello API 36) o versioni successive

Puoi utilizzare direttamente il metodo removeLaunchSecurityProtection() sull'oggetto Intent.

val i = intent
val iSublevel: Intent? = i.getParcelableExtra("sub_intent")
iSublevel?.removeLaunchSecurityProtection() // Opt out from hardening
iSublevel?.let { startActivity(it) }
Per le applicazioni compilate per Android 15 (livello API 35) o versioni precedenti

Sebbene non sia consigliato, puoi utilizzare la riflessione per accedere al metodo removeLaunchSecurityProtection().

val i = intent
val iSublevel: Intent? = i.getParcelableExtra("sub_intent", Intent::class.java)
try {
    val removeLaunchSecurityProtection = Intent::class.java.getDeclaredMethod("removeLaunchSecurityProtection")
    removeLaunchSecurityProtection.invoke(iSublevel)
} catch (e: Exception) {
    // Handle the exception, e.g., log it
} // Opt-out from the security hardening using reflection
iSublevel?.let { startActivity(it) }

Connettività

Android 16 (livello API 36) include le seguenti modifiche allo stack Bluetooth per migliorare la connettività con i dispositivi periferici.

Gestione migliorata delle perdite di obbligazioni

Starting in Android 16, the Bluetooth stack has been updated to improve security and user experience when a remote bond loss is detected. Previously, the system would automatically remove the bond and initiate a new pairing process, which could lead to unintentional re-pairing. We have seen in many instances apps not taking care of the bond loss event in a consistent way.

To unify the experience, Android 16 improved the bond loss handling to the system. If a previously bonded Bluetooth device could not be authenticated upon reconnection, the system will disconnect the link, retain local bond information, and display a system dialog informing users of the bond loss and directing them to re-pair.