Behavior changes: all apps

The Android 16 platform includes behavior changes that might affect your app. The following behavior changes apply to all apps when they run on Android 16, regardless of targetSdkVersion. You should test your app and then modify it as needed to support these changes, where applicable.

Make sure to also review the list of behavior changes that only affect apps targeting Android 16.

Core functionality

Android 16 (API level 36) includes the following changes that modify or expand various core capabilities of the Android system.

JobScheduler quota optimizations

从 Android 16 开始，我们将根据以下因素调整常规作业和加急作业的执行运行时配额：

• 应用所处的应用待机存储分区：在 Android 16 中，活跃待机存储分区将开始通过宽松的运行时配额强制执行。
• 如果作业在应用处于前台状态时开始执行：在 Android 16 中，如果作业在应用对用户可见时开始执行，并在应用变为不可见后继续执行，则会遵守作业运行时配额。
• 如果作业在运行前台服务时执行：在 Android 16 中，与前台服务同时执行的作业将遵守作业运行时配额。如果您利用作业进行用户发起的数据传输，请考虑改用用户发起的数据传输作业。

此变更会影响使用 WorkManager、JobScheduler 和 DownloadManager 调度的任务。如需调试作业停止的原因，我们建议您通过调用 WorkInfo.getStopReason()（对于 JobScheduler 作业，请调用 JobParameters.getStopReason()）来记录作业停止的原因。

如需了解应用的状态如何影响其可使用的资源，请参阅电源管理资源限制。 如需详细了解电池优化方面的最佳实践，请参阅有关针对任务调度 API 优化电池使用的指南。

我们还建议利用 Android 16 中引入的新 JobScheduler#getPendingJobReasonsHistory API 来了解作业未执行的原因。

测试

如需测试应用的行为，只要应用在 Android 16 设备上运行，您就可以启用对某些作业配额优化功能的替换。

如需停用“顶级状态将遵守作业运行时配额”的强制执行，请运行以下 adb 命令：

adb shell am compat enable OVERRIDE_QUOTA_ENFORCEMENT_TO_TOP_STARTED_JOBS APP_PACKAGE_NAME

如需停用“在与前台服务同时执行时，作业将遵守作业运行时配额”的强制执行，请运行以下 adb 命令：

adb shell am compat enable OVERRIDE_QUOTA_ENFORCEMENT_TO_FGS_JOBS APP_PACKAGE_NAME

如需测试特定应用待机分桶行为，您可以使用以下 adb 命令设置应用的应用待机分桶：

adb shell am set-standby-bucket APP_PACKAGE_NAME active|working_set|frequent|rare|restricted

如需了解应用所在的待机分桶，您可以使用以下 adb 命令获取应用的待机分桶：

adb shell am get-standby-bucket APP_PACKAGE_NAME

Abandoned empty jobs stop reason

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.

Fully deprecating 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.

Ordered broadcast priority scope no longer global

Android 应用可以为广播接收器定义优先级，以控制接收器接收和处理广播的顺序。对于清单声明的接收器，应用可以使用 android:priority 属性来定义优先级；对于上下文注册的接收器，应用可以使用 IntentFilter#setPriority() API 来定义优先级。发送广播时，系统会按接收器的优先级（从高到低）将其传送给接收器。

在 Android 16 中，无法保证使用 android:priority 属性或 IntentFilter#setPriority() 在不同进程中传送广播的顺序。广播优先级仅在同一应用进程内有效，而不会跨所有进程有效。

此外，广播优先级将自动限制在 (SYSTEM_LOW_PRIORITY + 1, SYSTEM_HIGH_PRIORITY - 1) 的范围内。只有系统组件才能将 SYSTEM_LOW_PRIORITY、SYSTEM_HIGH_PRIORITY 设置为广播优先级。

如果您的应用执行以下任一操作，可能会受到影响：

1. 您的应用声明了具有相同广播 intent 的多个进程，并且希望根据优先级以特定顺序接收这些 intent。
2. 您的应用进程与其他进程交互，并期望以特定顺序接收广播 intent。

如果进程需要相互协调，则应使用其他协调渠道进行通信。

ART internal changes

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 page size compatibility mode

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.

User experience and system UI

Android 16 (API level 36) includes the following changes that are intended to create a more consistent, intuitive user experience.

Deprecating disruptive accessibility announcements

Android 16 废弃了无障碍功能通告，其特征是使用 announceForAccessibility 或调度 TYPE_ANNOUNCEMENT 无障碍功能事件。这可能会给 TalkBack 和 Android 屏幕阅读器用户带来不一致的用户体验，而替代方案可以更好地满足各种 Android 辅助技术的用户需求。

替代方案示例：

• 对于窗口更改等重大界面更改，请使用 Activity.setTitle(CharSequence) 和 setAccessibilityPaneTitle(java.lang.CharSequence)。在 Compose 中，使用 Modifier.semantics { paneTitle = "paneTitle" }
• 如需向用户告知关键界面的更改，请使用 setAccessibilityLiveRegion(int)。在 Compose 中，请使用 Modifier.semantics { liveRegion = LiveRegionMode.[Polite|Assertive]}。应谨慎使用这些事件，因为它们可能会在每次更新视图时生成通知。
• 如需向用户发送错误通知，请发送类型为 AccessibilityEvent#CONTENT_CHANGE_TYPE_ERROR 的 AccessibilityEvent 并设置 AccessibilityNodeInfo#setError(CharSequence)，或使用 TextView#setError(CharSequence)。

已废弃的 announceForAccessibility API 的参考文档中包含有关建议替代方案的更多详细信息。

Support for 3-button navigation

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.

Automatic themed app icons

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.

Device form factors

Android 16 (API level 36) includes the following changes for apps when projected onto displays by virtual device owners.

Virtual device owner overrides

虚拟设备所有者是创建和管理虚拟设备的可信应用或特权应用。虚拟设备所有者在虚拟设备上运行应用，然后将应用投影到远程设备的显示屏上，例如个人电脑、虚拟现实设备或车载信息娱乐系统。虚拟设备所有者使用的是本地设备，例如手机。

手机上的虚拟设备所有者创建将应用投影到远程显示屏的虚拟设备。

按应用替换项

在搭载 Android 16（API 级别 36）的设备上，虚拟设备所有者可以替换其管理的特定虚拟设备上的应用设置。例如，为了改进应用布局，虚拟设备所有者在将应用投影到外部显示屏上时，可以忽略屏幕方向、宽高比和可调整大小性限制。

常见的重大更改

Android 16 的行为可能会影响应用在汽车显示屏或 Chromebook 等大屏幕设备规格上的界面，尤其是那些专为竖屏小显示屏设计的布局。如需了解如何让应用适应所有设备类型，请参阅关于自适应布局。

参考

配套应用串流

Security

Android 16 (API level 36) includes changes that promote system security to help protect apps and users from malicious apps.

Improved security against Intent redirection attacks

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.

Important: Opting out of security protections should be done with caution and only when absolutely necessary, as it can increase the risk of security vulnerabilities. Carefully assess the potential impact on your app's security before using this API.

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.

Caution: Using reflection can make your code more fragile and prone to errors, especially if the underlying API changes in future Android versions. Whenever possible, update your compile SDK to target Android 16 (API level 36) or higher to use the API directly.

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) }

Companion apps no longer notified of discovery timeouts

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.

Connectivity

Android 16 (API level 36) includes the following changes in Bluetooth stack to improve connectivity with peripheral devices.

Improved bond loss handling

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.