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 while 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：

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 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.

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：

• 如要進行重大的 UI 變更 (例如變更視窗)，請使用 Activity.setTitle(CharSequence) 和 setAccessibilityPaneTitle(java.lang.CharSequence)。在 Compose 中使用 Modifier.semantics { paneTitle = "paneTitle" }
• 如要通知使用者關鍵 UI 的變更，請使用 setAccessibilityLiveRegion(int)。在 Compose 中使用 Modifier.semantics { liveRegion = LiveRegionMode.[Polite|Assertive]}。這些事件應謹慎使用，因為每次 View 更新時，這些事件都可能產生通知。
• 如要通知使用者錯誤，請傳送 AccessibilityEvent#CONTENT_CHANGE_TYPE_ERROR 類型的 AccessibilityEvent，並設定 AccessibilityNodeInfo#setError(CharSequence)，或使用 TextView#setError(CharSequence)。

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 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)。

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

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各項指標，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，或是取得 URI 存取權來存取機密資料，進而竊取資料及執行任意程式碼。

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，預設安全行為可能會干擾正當的應用程式用途，因此可能需要停用。

針對 Android 16 (API 級別 36) 以上 SDK 編譯的應用程式

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.