行為變更：所有應用程式

Android 16 平台包含可能對應用程式造成影響的行為變更。無論 targetSdkVersion 為何，當應用程式在 Android 16 上執行時，下列行為變更將會套用至所有應用程式。您應測試應用程式，並視需要修改，以便在適當情況下支援這些變更。

另請務必查看僅對指定 Android 16 為目標版本的應用程式造成影響的行為變更。

核心功能

Android 16 (API 級別 36) 包含下列變更，可修改或擴充 Android 系統的各種核心功能。

JobScheduler 配額最佳化

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 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 information about how your app's state affects the resources it can use, see Power management resource limits. 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

放棄空白工作停止原因

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.

完全淘汰 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.

已排序的廣播優先順序範圍不再是全域

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.

ART 內部變更

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.

16 KB 頁面大小相容模式

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.

使用者體驗和系統 UI

Android 16 (API 級別 36) 包含下列變更，旨在打造更一致、直覺的使用者體驗。

淘汰令人混淆的無障礙工具公告

Android 16 已淘汰無障礙公告，這類公告的特色是使用 announceForAccessibility 或調度 TYPE_ANNOUNCEMENT 無障礙事件。這可能會為 TalkBack 和 Android 螢幕閱讀器的使用者帶來不一致的使用者體驗，而替代方案可在各種 Android 輔助技術中，滿足更廣泛的使用者需求。

替代方案範例：

如要進一步瞭解建議的替代方案，請參閱已淘汰的 announceForAccessibility API 參考說明文件。

支援三按鈕操作模式

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.

自動套用主題色應用程式圖示

Beginning with Android 16 QPR 2, Android automatically applies themes to app icons to create a cohesive home screen experience. This occurs if an app does not provide its own themed app icon. Apps can control the design of their themed app icon by including a monochrome layer within their adaptive icon and previewing what their app icon will look like in Android Studio.

裝置板型規格

Android 16 (API 級別 36) 包含以下變更，適用於虛擬裝置擁有者將應用程式投放到螢幕時。

虛擬裝置擁有者覆寫

虛擬裝置擁有者是可信任或具備特殊權限的應用程式，可建立及管理虛擬裝置。虛擬裝置擁有者可以在虛擬裝置上執行應用程式，然後將應用程式投影到遠端裝置的螢幕上，例如個人電腦、虛擬實境裝置或車輛資訊娛樂系統。虛擬裝置擁有者使用本機裝置，例如手機。

手機上的虛擬裝置擁有者建立虛擬裝置，將應用程式投放到遠端螢幕。

個別應用程式覆寫值

在搭載 Android 16 (API 級別 36) 的裝置上，虛擬裝置擁有者可以覆寫所管理特定虛擬裝置的應用程式設定。舉例來說，為了改善應用程式版面配置，虛擬裝置擁有者在將應用程式投影到外部螢幕時，可以忽略方向、長寬比和可調整大小的限制。

常見的破壞性變更

Android 16 的這項行為可能會影響應用程式在大型螢幕 (例如車輛螢幕或 Chromebook) 上的 UI，尤其是專為直向小螢幕設計的版面配置。如要瞭解如何讓應用程式自動調整版面，以配合所有裝置板型規格，請參閱「關於自動調整版面」。

參考資料

隨附應用程式串流

安全性

Android 16 (API 級別 36) 包含多項異動，可提升系統安全性，協助保護應用程式和使用者免受惡意應用程式侵害。

安全性提高，避免意圖重新導向攻擊

Android 16 provides default security against general Intent redirection attacks, with minimum compatibility and developer changes required.

We are introducing by-default security hardening solutions to Intent redirection exploits. In most cases, apps that use intents normally won't experience any compatibility issues; we've gathered metrics throughout our development process to monitor which apps might experience breakages.

Intent redirection in Android occurs when an attacker can partly or fully control the contents of an intent used to launch a new component in the context of a vulnerable app, while the victim app launches an untrusted sub-level intent in an extras field of an ("top-level") Intent. This can lead to the attacker app launching private components in the context of the victim app, triggering privileged actions, or gaining URI access to sensitive data, potentially leading to data theft and arbitrary code execution.

Opt out of Intent redirection handling

Android 16 introduces a new API that allows apps to opt out of launch security protections. This might be necessary in specific cases where the default security behavior interferes with legitimate app use cases.

For applications compiling against Android 16 (API level 36) SDK or higher

You can directly use the removeLaunchSecurityProtection() method on the Intent object.

val i = intent
val iSublevel: Intent? = i.getParcelableExtra("sub_intent")
iSublevel?.removeLaunchSecurityProtection() // Opt out from hardening
iSublevel?.let { startActivity(it) }
For applications compiling against Android 15 (API level 35) or lower

While not recommended, you can use reflection to access the removeLaunchSecurityProtection() method.

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) }

隨附應用程式不會再收到探索逾時通知

Android 16 introduces a new behavior during companion device pairing flow to protect the user's location privacy from malicious apps. All companion apps running on Android 16 are no longer directly notified of discovery timeout using RESULT_DISCOVERY_TIMEOUT. Instead, the user is notified of timeout events with a visual dialog. When the user dismisses the dialog, the app is alerted of the association failure with RESULT_USER_REJECTED.

The search duration has also been extended from the original 20 seconds, and the device discovery can be stopped by the user at any point during the search. If at least one device was discovered within the first 20 seconds of starting the search, the CDM stops searching for additional devices.

連線能力

Android 16 (API 級別 36) 包含藍牙堆疊的下列變更，可提升與周邊裝置的連線能力。

改善債券損失處理方式

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.