Android 16 平台包含一些行为变更,这些变更可能会影响您的应用。以下行为变更将影响在 Android 16 上运行的所有应用,无论采用哪种 targetSdkVersion
都不例外。您应该测试您的应用,然后根据需要进行修改,以支持这些变更(如果适用)。
此外,请务必查看仅影响以 Android 16 为目标平台的应用的行为变更列表。
核心功能
Android 16 包含以下更改,用于修改或扩展 Android 系统的各种核心功能。
JobScheduler 配额优化
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 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
被废弃的空作业停止原因
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.
完全弃用 JobInfo#setImportantWhileForeground
JobInfo.Builder#setImportantWhileForeground(boolean)
方法用于在调度应用位于前台或暂时豁免于后台限制时指示作业的优先级。
自 Android 12(API 级别 31)起,此方法已废弃。从 Android 16 开始,它不再有效,系统会忽略调用此方法。
此功能移除也适用于 JobInfo#isImportantWhileForeground()
。从 Android 16 开始,如果调用该方法,该方法会返回 false
。
有序广播优先级范围不再是全局
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:
- 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.
- 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 内部变更
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 页面大小兼容模式
Android 15 引入了对 16 KB 内存页面的支持,以优化平台性能。Android 16 添加了兼容模式,让一些针对 4 KB 内存页面构建的应用可以在配置为 16 KB 内存页面的设备上运行。
如果 Android 检测到您的应用具有 4 KB 对齐的内存页,则会自动使用兼容模式并向用户显示通知对话框。在 AndroidManifest.xml
中设置 android:pageSizeCompat
属性以启用向后兼容模式,将会阻止应用启动时显示对话框。为了获得最佳性能、可靠性和稳定性,您的应用仍应采用 16 KB 对齐。如需了解详情,请参阅我们近期发布的博文,了解如何更新应用以支持 16 KB 的内存页面。
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用户体验和系统界面
Android 16 进行了以下变更,旨在打造更一致、更直观的用户体验。
废弃干扰性无障碍功能播报
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
AccessibilityEvent
of typeAccessibilityEvent#CONTENT_CHANGE_TYPE_ERROR
and setAccessibilityNodeInfo#setError(CharSequence)
, or useTextView#setError(CharSequence)
.
The reference documentation for the deprecated
announceForAccessibility
API includes more details about
suggested alternatives.
支持“三按钮”导航
Android 16 为已正确迁移到预测性返回的应用的三按钮导航栏引入了预测性返回支持。长按返回按钮会启动预测性返回动画,让您预览返回滑动手势会打开的界面。
此行为适用于系统中支持预测性返回动画的所有区域,包括系统动画(返回主屏幕、跨任务和跨 activity)。
设备规格
Android 16 对虚拟设备所有者投影到显示屏上的应用做出了以下更改。
虚拟设备所有者替换项
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.
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Per-app overrides
On devices running Android 16, 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
Android 16 中包含一些有助于提升系统安全性的变更,可帮助保护应用和用户免受恶意应用的侵害。
增强了针对 intent 重定向攻击的安全性
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 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) }
连接
Android 16 在蓝牙堆栈中进行了以下更改,以改善与外围设备的连接。
改进了对债券损失的处理
从 Android 16 开始,蓝牙堆栈已更新,以便在检测到远程配对丢失时提高安全性和用户体验。以前,系统会自动解除配对并启动新的配对流程,这可能会导致意外重新配对。在许多情况下,我们发现应用未以一致的方式处理债券损失事件。
为了统一体验,Android 16 改进了系统的绑定丢失处理。如果之前配对的蓝牙设备在重新连接时无法进行身份验证,系统会断开关联,保留本地配对信息,并显示系统对话框,告知用户配对已断开并指示他们重新配对。