La piattaforma Android 14 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 14,
indipendentemente da
targetSdkVersion. Devi testare la tua app e poi modificarla in base alle necessità per supportarle correttamente, ove applicabile.
Assicurati di esaminare anche l'elenco delle modifiche al comportamento che interessano solo le app con targeting Android 14.
Funzionalità di base
Le sveglie esatte programmate sono vietate per impostazione predefinita
Exact alarms are meant for user-intentioned notifications, or for actions that
need to happen at a precise time. Starting in Android 14, the
SCHEDULE_EXACT_ALARM
permission is no longer being pre-granted to most newly installed apps
targeting Android 13 and higher—the permission is denied by default.
Learn more about the changes to the permission for scheduling exact alarms.
Le trasmissioni registrate al contesto vengono messe in coda mentre le app vengono memorizzate nella cache
On Android 14, the system can place context-registered broadcasts in a queue while the app is in the cached state. This is similar to the queuing behavior that Android 12 (API level 31) introduced for async binder transactions. Manifest-declared broadcasts aren't queued, and apps are removed from the cached state for broadcast delivery.
When the app leaves the cached state, such as returning to the foreground, the system delivers any queued broadcasts. Multiple instances of certain broadcasts might be merged into one broadcast. Depending on other factors, such as system health, apps might be removed from the cached state, and any previously queued broadcasts are delivered.
Le app possono terminare solo le proprie procedure in background
Starting in Android 14, when your app calls killBackgroundProcesses(),
the API can kill only the background processes of your own app.
If you pass in the package name of another app, this method has no effect on that app's background processes, and the following message appears in Logcat:
Invalid packageName: com.example.anotherapp
Your app shouldn't use the killBackgroundProcesses() API or otherwise attempt
to influence the process lifecycle of other apps, even on older OS versions.
Android is designed to keep cached apps in the background and kill them
automatically when the system needs memory. If your app kills other apps
unnecessarily, it can reduce system performance and increase battery consumption
by requiring full restarts of those apps later, which takes significantly more
resources than resuming an existing cached app.
L'MTU è impostato su 517 per il primo client GATT che richiede un MTU
A partire da Android 14, lo stack Bluetooth per Android è conforme in modo più rigoroso alla versione 5.2 della specifica Bluetooth Core e richiede l'MTU BLE ATT a 517 byte quando il primo client GATT richiede una MTU utilizzando l'API BluetoothGatt#requestMtu(int), ignorando tutte le successive richieste di MTU su quella connessione ACL.
Per affrontare questa modifica e rendere la tua app più solida, prendi in considerazione le seguenti opzioni:
- Il dispositivo periferico deve rispondere alla richiesta di MTU del dispositivo Android con un valore ragionevole consentito dalla periferica. Il
valore negoziato finale sarà un minimo del valore richiesto per Android e
il valore remoto fornito (ad esempio,
min(517, remoteMtu))- L'implementazione di questa correzione potrebbe richiedere un aggiornamento del firmware per la periferica
- In alternativa, limita le scritture delle caratteristiche GATT in base al minimo tra il valore supportato noto della tua periferica e la modifica dell'MTU ricevuta.
- Ricorda che devi ridurre di 5 byte le dimensioni supportate per le intestazioni
- Ad esempio:
arrayMaxLength = min(SUPPORTED_MTU, GATT_MAX_ATTR_LEN(517)) - 5
Nuovo motivo per cui un'app può essere inserita nel bucket in standby limitato
Android 14 introduce un nuovo motivo per cui un'app può essere inserita nel bucket in standby con restrizioni.
I job dell'app attivano più volte errori ANR a causa di timeout dei metodi onStartJob,
onStopJob o onBind.
(consulta JobScheduler rafforza il comportamento di callback e rete per le modifiche a onStartJob e onStopJob.)
Per monitorare se l'app è entrata o meno nel bucket in standby limitato, ti consigliamo di eseguire il logging con l'API UsageStatsManager.getAppStandbyBucket() durante l'esecuzione del job o UsageStatsManager.queryEventsForSelf() all'avvio dell'app.
Mlock limitato a 64 kB
In Android 14 (API level 34) and higher, the platform reduces the maximum memory
that can be locked using mlock() to 64 KB per process. In
previous versions, the limit was 64 MB per process. This restriction
promotes better memory management across apps and the system. To provide more
consistency across devices, Android 14 adds a new CTS test for the
new mlock() limit on compatible devices.
Il sistema applica l'utilizzo delle risorse delle app memorizzate nella cache
By design, an app's process is in a cached state when it's moved to the
background and no other app process components are running. Such an app process
is subject to being killed due to system memory pressure. Any work that
Activity instances perform after the onStop() method has been called and
returned, while in this state, is unreliable and strongly discouraged.
Android 14 introduces consistency and enforcement to this design. Shortly after an app process enters a cached state, background work is disallowed, until a process component re-enters an active state of the lifecycle.
Apps that use typical framework-supported lifecycle APIs – such as
services, JobScheduler, and Jetpack WorkManager – shouldn't be
impacted by these changes.
Esperienza utente
Modifiche all'esperienza degli utenti con le notifiche non ignorabili
If your app shows non-dismissable foreground notifications to users, Android 14 has changed the behavior to allow users to dismiss such notifications.
This change applies to apps that prevent users from dismissing foreground
notifications by setting Notification.FLAG_ONGOING_EVENT through
Notification.Builder#setOngoing(true) or
NotificationCompat.Builder#setOngoing(true). The behavior of
FLAG_ONGOING_EVENT has changed to make such notifications actually
dismissable by the user.
These kinds of notifications are still non-dismissable in the following conditions:
- When the phone is locked
- If the user selects a Clear all notification action (which helps with accidental dismissals)
Also, this new behavior doesn't apply to notifications in the following use cases:
CallStylenotifications- Device policy controller (DPC) and supporting packages for enterprise
- Media notifications
- The default Search Selector package
Le informazioni sulla sicurezza dei dati sono più visibili
To enhance user privacy, Android 14 increases the number of places where the system shows the information you have declared in the Play Console form. Currently, users can view this information in the Data safety section on your app's listing in Google Play.
We encourage you to review your app's location data sharing policies and take a moment to make any applicable updates to your app's Google Play Data safety section.
Learn more in the guide about how data safety information is more visible on Android 14.
Accessibilità
Ridimensionamento non lineare dei caratteri al 200%
Starting in Android 14, the system supports font scaling up to 200%, providing low-vision users with additional accessibility options that align with Web Content Accessibility Guidelines (WCAG).
If you already use scaled pixels (sp) units to define text sizing, then this change probably won't have a high impact on your app. However, you should perform UI testing with the maximum font size enabled (200%) to ensure that your app can accommodate larger font sizes without impacting usability.
Sicurezza
Livello API target installabile minimo
Starting with Android 14, apps with a
targetSdkVersion lower than 23
can't be installed. Requiring apps to meet these minimum target API level
requirements improves security and privacy for users.
Malware often targets older API levels in order to bypass security and privacy
protections that have been introduced in newer Android versions. For example,
some malware apps use a targetSdkVersion of 22 to avoid being subjected to the
runtime permission model introduced in 2015 by Android 6.0 Marshmallow (API
level 23). This Android 14 change makes it harder for malware to avoid security
and privacy improvements.
Attempting to install an app targeting a lower API level will result in an
installation failure, with the following message appearing in Logcat:
INSTALL_FAILED_DEPRECATED_SDK_VERSION: App package must target at least SDK version 23, but found 7
On devices upgrading to Android 14, any apps with a targetSdkVersion lower
than 23 will remain installed.
If you need to test an app targeting an older API level, use the following ADB command:
adb install --bypass-low-target-sdk-block FILENAME.apk
I nomi dei pacchetti dei proprietari dei media potrebbero essere oscurati
The media store supports queries for the OWNER_PACKAGE_NAME column, which
indicates the app that stored a particular media file. Starting in Android
14, this value is redacted unless at least one of the following conditions is
true:
- The app that stored the media file has a package name that is always visible to other apps.
The app that queries the media store requests the
QUERY_ALL_PACKAGESpermission.
Learn more about how Android filters package visibility for privacy purposes.