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

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 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，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 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

Android 16 為已正確遷移至預測返回功能的應用程式，提供 3 鍵導覽的預測返回功能支援。長按返回按鈕會啟動預測返回動畫，讓您預覽返回滑動手勢會帶您前往的位置。

這項行為適用於系統中所有支援預測返回動畫的區域，包括系統動畫 (返回首頁、跨工作和跨活動)。

在 3 個按鈕操作模式中，預測返回動畫。

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.

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 提供預設安全性，可防範一般Intent重新導向攻擊，且只需進行最少的相容性調整和開發人員變更。

我們即將推出預設安全強化解決方案，以防範Intent 重新導向漏洞。在大多數情況下，使用意圖的應用程式通常不會遇到任何相容性問題；我們在開發過程中收集了指標，以監控哪些應用程式可能會發生中斷。

Android 發生意圖重新導向的情況，是指攻擊者可以部分或完整地控管某個意圖的內容，將該意圖用於在含有安全漏洞的應用程式環境中啟動新元件，而受害應用程式會在 ("頂層") Intent 的 Extras 欄位中啟動不受信任的次層意圖。這可能會導致攻擊者應用程式在受害應用程式的環境中啟動私人元件、觸發具備特殊權限的動作，或取得機密資料的 URI 存取權，進而導致資料竊取及執行任意程式碼。

選擇不處理意圖重新導向

Android 16 推出新的 API，可讓應用程式選擇停用啟動安全防護措施。在特定情況下，預設安全性行為可能會干擾正當的應用程式用途，因此可能需要停用。

如果應用程式是針對 Android 16 (API 級別 36) 以上版本的 SDK 編譯

您可以直接在 Intent 物件上使用 removeLaunchSecurityProtection() 方法。

val i = intent
val iSublevel: Intent? = i.getParcelableExtra("sub_intent")
iSublevel?.removeLaunchSecurityProtection() // Opt out from hardening
iSublevel?.let { startActivity(it) }
針對 Android 15 (API 級別 35) 以下版本編譯的應用程式

雖然不建議，但您可以使用反射來存取 removeLaunchSecurityProtection() 方法。

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。