Verhaltensänderungen: alle Apps

Die Android 14-Plattform umfasst Verhaltensänderungen, die sich auf Ihre App auswirken können. Die folgenden Verhaltensänderungen gelten für alle Apps, die unter Android 14 ausgeführt werden, unabhängig von targetSdkVersion. Du solltest deine Anwendung testen und dann bei Bedarf anpassen, damit sie korrekt unterstützt werden.

Sieh dir auch die Liste der Verhaltensänderungen an, die nur Apps betreffen, die auf Android 14 ausgerichtet sind.

Hauptfunktion

Genaue Alarme programmieren, werden standardmäßig verweigert

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.

Kontextregistrierte Broadcasts werden in die Warteschlange gestellt, während Apps im Cache gespeichert werden

Unter Android 14 kann das System kontextregistrierte Broadcasts in eine Warteschlange stellen, während sich die App im Cache-Status befindet. Dies ähnelt dem Warteschlangenverhalten, das Android 12 (API-Level 31) für asynchrone Binder-Transaktionen eingeführt hat. Vom Manifest deklarierte Broadcasts werden nicht in die Warteschlange gestellt und Apps werden für die Übermittlung von Broadcasts aus dem Cache-Status entfernt.

Wenn die App den Cache-Status verlässt, z. B. in den Vordergrund zurückkehrt, sendet das System alle in der Warteschlange befindlichen Broadcasts. Mehrere Instanzen bestimmter Broadcasts können zu einer Übertragung zusammengeführt werden. Abhängig von anderen Faktoren, wie dem Systemzustand, können Anwendungen aus dem Cache-Status entfernt und alle zuvor in die Warteschlange gestellten Übertragungen zugestellt werden.

Apps können nur ihre eigenen Hintergrundprozesse beenden

Wenn deine App ab Android 14 killBackgroundProcesses() aufruft, kann die API nur die Hintergrundprozesse deiner eigenen App beenden.

Wenn Sie den Paketnamen einer anderen Anwendung übergeben, hat diese Methode keine Auswirkungen auf die Hintergrundprozesse dieser Anwendung. In Logcat wird dann die folgende Meldung angezeigt:

Invalid packageName: com.example.anotherapp

Ihre App darf die killBackgroundProcesses() API nicht verwenden und auch nicht anderweitig versuchen, den Prozesslebenszyklus anderer Apps zu beeinflussen, auch nicht bei älteren Betriebssystemversionen. Unter Android bleiben im Cache gespeicherte Apps im Hintergrund und beendet sie automatisch, wenn das System Arbeitsspeicher benötigt. Wenn Ihre App andere Apps unnötigerweise beendet, kann sie die Systemleistung verringern und den Akkuverbrauch erhöhen, da diese Apps später vollständig neu gestartet werden müssen. Dadurch werden deutlich mehr Ressourcen benötigt als die Nutzung einer vorhandenen im Cache gespeicherten App.

Die MTU wird für den ersten GATT-Client, der eine MTU anfordert, auf 517 eingestellt.

Starting from Android 14, the Android Bluetooth stack more strictly adheres to Version 5.2 of the Bluetooth Core Specification and requests the BLE ATT MTU to 517 bytes when the first GATT client requests an MTU using the BluetoothGatt#requestMtu(int) API, and disregards all subsequent MTU requests on that ACL connection.

To address this change and make your app more robust, consider the following options:

  • Your peripheral device should respond to the Android device's MTU request with a reasonable value that can be accommodated by the peripheral. The final negotiated value will be a minimum of the Android requested value and the remote provided value (for example, min(517, remoteMtu))
    • Implementing this fix could require a firmware update for peripheral
  • Alternatively, limit your GATT characteristic writes based on the minimum between the known supported value of your peripheral and the received MTU change
    • A reminder that you should reduce 5 bytes from the supported size for the headers
    • For example: arrayMaxLength = min(SUPPORTED_MTU, GATT_MAX_ATTR_LEN(517)) - 5

Neuer Grund, warum eine Anwendung in den eingeschränkten Standby-Bucket platziert werden kann

Android 14 introduces a new reason an app can be placed into the restricted standby bucket. The app's jobs trigger ANR errors multiple times due to onStartJob, onStopJob, or onBind method timeouts. (See JobScheduler reinforces callback and network behavior for changes to onStartJob and onStopJob.)

To track whether or not the app has entered the restricted standby bucket, we recommend logging with the API UsageStatsManager.getAppStandbyBucket() on job execution or UsageStatsManager.queryEventsForSelf() on app startup.

mlock beschränkt auf 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.

System erzwingt die Nutzung von im Cache gespeicherten App-Ressourcen

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.

Nutzererfahrung

Änderungen an der Darstellung von Benachrichtigungen, die sich nicht schließen lassen

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:

  • CallStyle notifications
  • Device policy controller (DPC) and supporting packages for enterprise
  • Media notifications
  • The default Search Selector package

Bessere Sichtbarkeit von Informationen zur Datensicherheit

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.

Bedienungshilfen

Nicht lineare Schriftskalierung auf 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.

Sicherheit

Minimales installierbares Ziel-API-Level

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

Paketnamen von Mediainhabern werden möglicherweise entfernt

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_PACKAGES permission.

Learn more about how Android filters package visibility for privacy purposes.