Modifiche al comportamento: tutte le app

La piattaforma Android 17 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 17, indipendentemente dal targetSdkVersion. Devi testare la tua app e poi modificarla in base alle necessità per supportare queste modifiche, ove applicabile.

Assicurati di esaminare anche l'elenco delle modifiche al comportamento che interessano solo le app che hanno come target Android 17.

Funzionalità di base

Android 17 (livello API 37) include le seguenti modifiche che modificano o espandono varie funzionalità di base del sistema Android.

Limiti di memoria per le app

Android 17 introduces app memory limits based on the device's total RAM to create a more stable and deterministic environment for your applications and Android users. In Android 17, limits are set conservatively to establish system baselines, targeting extreme memory leaks and other outliers before they trigger system-wide instability resulting in UI stuttering, higher battery drain, and apps being killed. While we anticipate minimal impact on the vast majority of app sessions, we recommend the following memory best practices, including establishing a baseline for memory.

You can determine if your app session was impacted by calling getDescription in ApplicationExitInfo; if your app was affected, the exit reason will be REASON_OTHER and the description will contain the string "MemoryLimiter:AnonSwap" along with other information. You can also use trigger-based profiling with TRIGGER_TYPE_ANOMALY to get heap dumps that are collected when the memory limit is hit.

The Manage your app's memory documentation gives information to help you diagnose your app's memory issues and optimize its resource consumption.

Test your app's behavior under the memory constraints

You can use Android Debug Bridge (adb) to adjust or disable the memory limits on any device that imposes them. The shell command am provides three subcommands to adjust the memory limits. (These commands have no effect on a device which does not impose memory limits.)

  • am memory-limiter ignore <uid>|none|all
  • am memory-limiter manual <pid> <limit>|max|none
  • am memory-limiter status
ignore

Instructs the memory limiter to ignore some or all processes. Passing a UID instructs the memory limiter to ignore all processes associated with that UID. You can also pass all (ignore all processes) or none (do not ignore any processes). Passing none overrides any previous calls to am memory-limiter ignore.

If you instruct the memory limiter to ignore a process, you can still apply a manual memory limit to the process by calling am memory-limiter manual.

manual

Instructs the system to impose a memory constraint on the process with the specified PID. The memory constraint is specified as an integer number of MB; for example, passing 30 specifies that the process is limited to 30 MB of memory. Passing max removes all memory limits on that process. Passing none removes any manual limits set on the process, restoring the system's default limit (if any).

status

Reports the current status of the memory limiter. The status includes the memory limits imposed on visible and non-visible processes.

Privacy

Android 17 include le seguenti modifiche per migliorare la privacy degli utenti.

Protezione OTP via SMS

Beginning with Android 17, Android is expanding its protection for SMS messages containing one-time passwords (OTP).

In previous versions of Android, this protection was primarily focused on the SMS Retriever format. Delivery of messages containing an SMS retriever hash was delayed for most apps for three hours. However, certain certain apps (like the default SMS handler) were exempt from the delay, and the app that owned the hash was also exempted.

Beginning with Android 17, the protection is also applied to WebOTP format messages. If an app has permission to read SMS messages but is not the intended recipient of a WebOTP message (as determined by domain verification), the message is not accessible to the app until three hours after the message's receipt. This change is intended to improve user security by ensuring that only apps associated with the domain mentioned in the message can programmatically read the verification code.

During this three hour delay, the SMS_RECEIVED_ACTION broadcast is withheld and SMS provider database queries are filtered. The SMS message is available to these apps after the delay. This change applies to all apps, regardless of their target API level.

Certain apps such as the default SMS assistant app, connected device companion apps, etc., are exempted from this delay. All apps that rely on reading SMS messages for OTP extraction should transition to using SMS Retriever or SMS User Consent APIs to ensure continued functionality.

Sicurezza

Android 17 include i seguenti miglioramenti alla sicurezza di app e dispositivi.

Piano di ritiro di usesClearTraffic

In a future release, we plan to deprecate the usesCleartextTraffic element. Apps that need to make unencrypted (HTTP) connections should migrate to using a network security configuration file, which lets you specify which domains your app needs to make cleartext connections to.

Be aware that network security configuration files are only supported on API levels 24 and higher. If your app has a minimum API level lower than 24, you should do both of the following:

  • Set the usesCleartextTraffic attribute to true
  • Use a network configuration file

If your app's minimum API level is 24 or higher, you can use a network configuration file and you don't need to set usesCleartextTraffic.

Limita le concessioni implicite di URI

Attualmente, se un'app avvia un intent con un URI che ha l'azione ACTION_SEND, ACTION_SEND_MULTIPLE o ACTION_IMAGE_CAPTURE, il sistema concede automaticamente le autorizzazioni URI di lettura e scrittura all'app di destinazione. A partire da Android 18, il sistema non concederà più automaticamente queste autorizzazioni. Per questo motivo, consigliamo alle app di concedere esplicitamente le autorizzazioni URI pertinenti anziché fare affidamento sul sistema per concederle.

Per rilevare l'utilizzo di questi intent nella tua app, utilizza StrictMode con detectImplicitUriPermissionGrant() per attivare una violazione:

Kotlin

val policy = StrictMode.VmPolicy.Builder()
    .detectImplicitUriPermissionGrant()
    .penaltyLog()
    .build()
StrictMode.setVmPolicy(policy)

Java

StrictMode.VmPolicy policy = new StrictMode.VmPolicy.Builder()
    .detectImplicitUriPermissionGrant()
    .penaltyLog()
    .build();
StrictMode.setVmPolicy(policy);

In alternativa, puoi monitorare le eccezioni registrate contenenti il messaggio Please set the grant explicitly in the app visualizzato quando il sistema imposta implicitamente la concessione. Puoi monitorare questi log utilizzando il seguente comando adb:

adb logcat | grep "Please set the grant explicitly in the app"

Per concedere esplicitamente le autorizzazioni necessarie, aggiungi il flag FLAG_GRANT_READ_URI_PERMISSION agli intent ACTION_SEND e ACTION_SEND_MULTIPLE:

Kotlin

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)

Java

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

Includi i flag FLAG_GRANT_READ_URI_PERMISSION e FLAG_GRANT_WRITE_URI_PERMISSION per gli intent ACTION_IMAGE_CAPTURE:

Kotlin

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION)

Java

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

Limiti del keystore per app

Apps should avoid creating excessive numbers of keys in Android Keystore, because it is a shared resource for all apps on the device. Beginning with Android 17, the system enforces a limit on the number of keys an app can own. The limit is 50,000 keys for non-system apps targeting Android 17 (API level 37) or higher, and 200,000 keys for all other apps. System apps have a limit of 200,000 keys, regardless of which API level they target.

If an app attempts to create keys beyond the limit, the creation fails with a KeyStoreException. The exception's message string contains information about the key limit. If the app calls getNumericErrorCode() on the exception, the return value depends on what API level the app targets:

  • Apps targeting Android 17 (API level 37) or higher: getNumericErrorCode() returns the new ERROR_TOO_MANY_KEYS value.
  • All other apps: getNumericErrorCode() returns ERROR_INCORRECT_USAGE.

Bloccare il traffico di loopback tra profili

A partire da Android 17, il traffico di loopback tra profili non è più consentito per impostazione predefinita. Il traffico di loopback all'interno dello stesso profilo non è interessato. Questa modifica si applica a tutte le app in esecuzione su Android 17 o versioni successive, indipendentemente dal livello API di destinazione dell'app.

Esperienza utente e UI di sistema

Android 17 include le seguenti modifiche volte a creare un'esperienza utente più coerente e intuitiva.

Ripristino della visibilità predefinita dell'IME dopo la rotazione

A partire da Android 17, quando la configurazione del dispositivo cambia (ad esempio tramite la rotazione) e questo non viene gestito dall'app stessa, la visibilità della tastiera virtuale precedente non viene ripristinata.

Se la tua app subisce una modifica della configurazione che non gestisce e ha bisogno che la tastiera sia visibile dopo la modifica, devi richiederlo esplicitamente. Puoi effettuare questa richiesta in uno dei seguenti modi:

  • Imposta l'attributo android:windowSoftInputMode su stateAlwaysVisible.
  • Richiedi la tastiera su schermo a livello di programmazione nel metodo onCreate() dell'attività o aggiungi il metodo onConfigurationChanged().

Input umano

Android 17 include le seguenti modifiche che influiscono sul modo in cui le app interagiscono con i dispositivi di input umani come tastiere e touchpad.

I touchpad forniscono eventi relativi per impostazione predefinita durante l'acquisizione del puntatore

Beginning with Android 17, if an app requests pointer capture using View.requestPointerCapture() and the user uses a touchpad, the system recognizes pointer movement and scrolling gestures from the user's touches and reports them to the app in the same way as pointer and scroll wheel movements from a captured mouse. In most cases, this removes the need for apps that support captured mice to add special handling logic for touchpads. For more details, see the documentation for View.POINTER_CAPTURE_MODE_RELATIVE.

Previously, the system did not attempt to recognize gestures from the touchpad, and instead delivered the raw, absolute finger locations to the app in a similar format to touchscreen touches. If an app still requires this absolute data, it should call the new View.requestPointerCapture(int) method with View.POINTER_CAPTURE_MODE_ABSOLUTE instead.

Media

Android 17 include le seguenti modifiche al comportamento dei contenuti multimediali.

Protezione dell'audio in background

A partire da Android 17, il framework audio applica restrizioni alle interazioni audio in background, tra cui la riproduzione audio, le richieste di focus audio e le API di modifica del volume, per garantire che queste modifiche vengano avviate intenzionalmente dall'utente.

Se l'app tenta di chiamare le API audio mentre non si trova in un ciclo di vita valido, le API di riproduzione audio e di modifica del volume non riescono in modo silenzioso senza generare un'eccezione o fornire un messaggio di errore. L'API di focus audio non riesce con il codice risultato AUDIOFOCUS_REQUEST_FAILED.

Per ulteriori informazioni, incluse le strategie di mitigazione, consulta Protezione dell'audio in background .

Connettività

Android 17 include le seguenti modifiche per migliorare la connettività del dispositivo.

Riaccoppiamento autonomo per le perdite di associazione Bluetooth

Android 17 introduces autonomous re-pairing, a system-level enhancement designed to automatically resolve Bluetooth bond loss.

Previously, if a bond was lost, users had to manually navigate to Settings to unpair and then re-pair the peripheral. This feature builds upon the security improvement of Android 16 by allowing the system to re-establish bonds in the background without requiring users to manually navigate to Settings to unpair and re-pair peripherals.

While most apps will not require code changes, developers should be aware of the following behavior changes in Bluetooth stack:

  • New pairing context: The ACTION_PAIRING_REQUEST now includes the EXTRA_PAIRING_CONTEXT extra which allows apps to distinguish between a standard pairing request and an autonomous system-initiated re-pairing attempt.
  • Conditional key updates: Existing security keys will only be replaced if the re-pairing is successful and new connection meets or exceeds the security level of the previous bond.
  • Modified intent timing: The ACTION_KEY_MISSING intent is now broadcast only if the autonomous re-pairing attempt fails. This reduces unnecessary error handling in the app if the system successfully recovers the bond in the background.
  • User notification: The system manages re-pairing via new UI notifications and dialogs. Users will be prompted to confirm the re-pairing attempt to ensure they are aware of the reconnection.

Peripheral device manufacturers and companion app developers should verify that hardware and app gracefully handle bond transitions. To test this behavior, simulate a remote bond loss using either of the following methods:

  • Manually remove the bond information from the peripheral device
  • Manually unpair the device in: Settings > Connected devices