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。您必須測試自己的應用程式,並視需要進行修改,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) 包含下列異動項目,這類變更會修改或擴充 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
JobInfo.Builder#setImportantWhileForeground(boolean) 方法會在排程應用程式處於前景或暫時豁免背景限制時,指出工作的重要性。
自 Android 12 (API 級別 31) 起,此方法已淘汰。自 Android 16 起,這項方法不再有效,系統會忽略呼叫此方法的行為。
這項功能移除作業也適用於 JobInfo#isImportantWhileForeground()。自 Android 16 起,如果呼叫該方法,該方法會傳回 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_PRIORITY、SYSTEM_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:
- 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。
- 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 推出了 16 KB 記憶體分頁支援功能,以提升平台效能。Android 16 新增了相容模式,可讓為 4 KB 記憶體分頁建構的部分應用程式,在針對 16 KB 記憶體分頁設定的裝置上執行。
當應用程式在搭載 Android 16 以上版本的裝置上執行時,如果 Android 偵測到應用程式有 4 KB 對齊的記憶體分頁,就會自動使用相容性模式,並向使用者顯示通知對話方塊。在 AndroidManifest.xml 中設定 android:pageSizeCompat 屬性以啟用向後相容性模式,可防止應用程式啟動時顯示對話方塊。如要使用 android:pageSizeCompat 屬性,請使用 Android 16 SDK 編譯應用程式。
為獲得最佳效能、可靠性和穩定性,應用程式仍應以 16 KB 對齊。如要進一步瞭解如何更新應用程式以支援 16 KB 記憶體分頁,請參閱近期的網誌文章。
使用者體驗和系統 UI
Android 16 (API 級別 36) 包含下列異動,目的是打造更一致、直觀的使用者體驗。
停止使用干擾性無障礙公告
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:
- For significant UI changes like window changes, use
Activity.setTitle(CharSequence)andsetAccessibilityPaneTitle(java.lang.CharSequence). In Compose, useModifier.semantics { paneTitle = "paneTitle" } - To inform the user of changes to critical UI, use
setAccessibilityLiveRegion(int). In Compose, useModifier.semantics { liveRegion = LiveRegionMode.[Polite|Assertive]}. These should be used sparingly as they may generate announcements every time a View is updated. - To notify users about errors, send an
AccessibilityEventof typeAccessibilityEvent#CONTENT_CHANGE_TYPE_ERRORand setAccessibilityNodeInfo#setError(CharSequence), or useTextView#setError(CharSequence).
The reference documentation for the deprecated
announceForAccessibility API includes more details about
suggested alternatives.
支援三按鈕操作
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).
自動套用主題色應用程式圖示
從 Android 16 QPR 2 開始,Android 會自動將主題套用至應用程式圖示,打造一致的主畫面體驗。如果應用程式未提供自己的主題式應用程式圖示,就會發生這種情況。應用程式可以在自動調整式圖示中加入單色圖層,並在 Android Studio 中預覽應用程式圖示的外觀,藉此控制主題式應用程式圖示的設計。
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.
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
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) 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
自 Android 16 起,我們已更新藍牙堆疊,以便在偵測到遠端連結遺失時,提升安全性和使用者體驗。先前系統會自動移除配對連結,並啟動新的配對程序,這可能會導致不小心重新配對。我們發現許多應用程式並未以一致的方式處理連結失效事件。
為統一使用體驗,Android 16 改善了系統的連結遺失處理方式。如果先前已配對的藍牙裝置無法在重新連線時驗證,系統會中斷連結、保留本機配對資訊,並顯示系統對話方塊,告知使用者配對失敗,並引導他們重新配對。