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

因工作空白而停止的原因

當與工作相關聯的 JobParameters 物件已收集為垃圾,但未呼叫 JobService#jobFinished(JobParameters, boolean) 來傳送工作完成信號時,就會發生遺棄的工作。這表示工作可能在未經應用程式察覺的情況下執行及重新排程。

依賴 JobScheduler 的應用程式不會維持對 JobParameters 物件的強參照,且超時現在會授予新的 STOP_REASON_TIMEOUT_ABANDONED 工作停止原因,而非 STOP_REASON_TIMEOUT

如果新棄站原因經常發生,系統會採取緩解措施來減少工作頻率。

應用程式應使用新的停止原因來偵測並減少遺失的工作。

如果您使用 WorkManager、AsyncTask 或 DownloadManager,則不會受到影響,因為這些 API 會代表應用程式管理工作生命週期。

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 應用程式可定義廣播接收器的優先順序,藉此控制接收器接收及處理廣播的順序。對於資訊清單宣告的接收器,應用程式可以使用 android:priority 屬性來定義優先順序,而對於內容註冊的接收器,應用程式可以使用 IntentFilter#setPriority() API 來定義優先順序。傳送廣播訊息時,系統會依優先順序 (由高至低) 將訊息傳送給接收器。

在 Android 16 中,系統無法保證使用 android:priority 屬性或在不同程序中使用 IntentFilter#setPriority() 的廣播傳送順序。廣播優先順序只會在相同的應用程式程序中受到尊重,而不會跨所有程序。

此外,廣播優先順序會自動限制在 (SYSTEM_LOW_PRIORITY + 1, SYSTEM_HIGH_PRIORITY - 1) 的範圍內。只有系統元件可將 SYSTEM_LOW_PRIORITYSYSTEM_HIGH_PRIORITY 設為廣播優先順序。

如果您的應用程式執行下列任一操作,可能會受到影響:

  1. 您的應用程式已宣告多個使用相同廣播意圖的程序,並且預期會按照優先順序接收這些意圖。
  2. 您的應用程式程序會與其他程序互動,並預期以特定順序接收廣播意圖。

如果程序需要相互協調,則應使用其他協調管道進行通訊。

ART 內部變更

Android 16 包含 Android 執行階段 (ART) 的最新更新,可改善 Android 執行階段 (ART) 的效能,並提供其他 Java 功能的支援。透過 Google Play 系統更新,這些改善項目也適用於搭載 Android 12 (API 級別 31) 以上版本的十億部裝置

隨著這些變更發布,依賴 ART 內部結構的程式庫和應用程式程式碼,可能無法在搭載 Android 16 的裝置上正常運作,也無法在透過 Google Play 系統更新更新 ART 模組的舊版 Android 上正常運作。

依賴內部結構 (例如 非 SDK 介面) 可能會導致相容性問題,但特別要避免依賴利用內部 ART 結構的程式碼 (或包含程式碼的程式庫),因為 ART 變更並未與裝置執行的平台版本綁定,且會透過 Google Play 系統更新傳送至十億部裝置。

所有開發人員都應在 Android 16 上徹底測試應用程式,檢查應用程式是否受到影響。此外,請檢查已知問題,瞭解您的應用程式是否依附我們已識別的任何程式庫,而這些程式庫又依附 ART 內部結構。如果確實有受到影響的應用程式程式碼或程式庫依附元件,請盡可能尋找公用 API 替代方案,並在問題追蹤工具中建立功能要求,為新的用途要求公用 API。

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) 包含下列異動,旨在打造更一致、直觀的使用者體驗。

淘汰令人混淆的無障礙公告

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.

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.

自動套用主題色至應用程式圖示

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

A virtual device owner is a trusted or privileged app that creates and manages a virtual device. Virtual device owners run apps on a virtual device and then project the apps to the display of a remote device, such as a personal computer, virtual reality device, or car infotainment system. The virtual device owner is on a local device, such as a mobile phone.

Virtual device owner on phone creates virtual device that projects app to remote display.

Per-app overrides

On devices running Android 16 (API level 36), virtual device owners can override app settings on select virtual devices that the virtual device owners manage. For example, to improve app layout, a virtual device owner can ignore orientation, aspect ratio, and resizability restrictions when projecting apps onto an external display.

Common breaking changes

The Android 16 behavior might impact your app's UI on large screen form factors such as car displays or Chromebooks, especially layouts that were designed for small displays in portrait orientation. To learn how to make your app adaptive for all device form factors, see About adaptive layouts.

References

Companion app streaming

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) 的藍牙堆疊包含下列變更,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.