行为变更：以 Android 16 或更高版本为目标平台的应用

与早期版本一样，Android 16 包含一些行为变更，这些变更可能会影响您的应用。以下行为变更仅影响以 Android 16 或更高版本为目标平台的应用。如果您的应用以 Android 16 或更高版本为目标平台，您应该修改自己的应用以支持这些行为（如果适用）。

请务必查看对 Android 16 上运行的所有应用都有影响的行为变更列表（无论应用的 targetSdkVersion 如何）。

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。

无边框设计停用退出选项

Android 15 强制为以 Android 15（API 级别 35）为目标平台的应用启用边到边，但您的应用可以通过将 R.attr#windowOptOutEdgeToEdgeEnforcement 设为 true 来选择停用。对于以 Android 16 为目标平台的应用，R.attr#windowOptOutEdgeToEdgeEnforcement 已废弃并处于停用状态，并且您的应用无法选择停用全屏显示。

如需在 Android 16 Beta 版 2 中进行测试，请确保您的应用支持边到边，并移除对 R.attr#windowOptOutEdgeToEdgeEnforcement 的任何使用。如需支持边到边，请参阅 Compose 和 View 指南。如有疑虑，请在反馈页面上通过问题跟踪器与我们联系。

需要迁移或停用预测性返回

对于以 Android 16 或更高版本为目标平台且在 Android 16 或更高版本的设备上运行的应用，预测性返回系统动画（返回主屏幕、跨任务和跨 activity）默认处于启用状态。此外，系统不会调用 onBackPressed，也不会再调度 KeyEvent.KEYCODE_BACK。

如果您的应用拦截了返回事件，并且您尚未迁移到预测性返回，请更新应用以使用受支持的返回导航 API；或者，在应用的 AndroidManifest.xml 文件的 <application> 或 <activity> 标记中将 android:enableOnBackInvokedCallback 属性设置为 false，以暂时停用此功能。

“返回主页”预测性返回动画。

预测性跨 activity 动画。

预测性跨任务动画。

优雅字体 API 已废弃并停用

以 Android 15（API 级别 35）为目标平台的应用的 elegantTextHeight TextView 属性默认设置为 true，从而将紧凑字体替换为更易于阅读的字体。您可以通过将 elegantTextHeight 属性设置为 false 来替换此设置。

Android 16 弃用了 elegantTextHeight 属性，并且在您的应用以 Android 16 为目标平台后，系统会忽略该属性。这些 API 控制的“界面字体”即将停用，因此您应调整所有布局，以确保以阿拉伯语、老挝语、缅甸语、泰米尔语、古吉拉特语、卡纳达语、马拉雅拉姆语、奥里亚语、泰卢固语或泰语呈现一致且可持续的文字。

对于以 Android 14（API 级别 34）及更低版本为目标平台的应用，或者对于通过将 elegantTextHeight 属性设置为 false 而替换默认值的以 Android 15（API 级别 35）为目标平台的应用，elegantTextHeight 行为。

对于以 Android 16 为目标平台的应用，或者对于未通过将 elegantTextHeight 属性设置为 false 来替换默认值的以 Android 15（API 级别 35）为目标平台的应用，elegantTextHeight 行为。

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。

固定费率工作调度优化

在以 Android 16 为目标平台之前，如果 scheduleAtFixedRate 因不在有效的进程生命周期内而错过了任务执行，则当应用返回到有效的生命周期时，所有错过的执行会立即执行。

以 Android 16 为目标平台时，当应用返回到有效的生命周期时，系统会立即执行最多 1 次未执行的 scheduleAtFixedRate 执行。此行为变更预计会提升应用性能。在您的应用中测试此行为，检查您的应用是否受到影响。您还可以使用应用兼容性框架并启用 STPE_SKIP_MULTIPLE_MISSED_PERIODIC_TASKS 兼容性标志进行测试。

设备规格

Android 16 对在大屏设备上显示的应用做出了以下更改。

自适应布局

With Android apps now running on a variety of devices (such as phones, tablets, foldables, desktops, cars, and TVs) and windowing modes on large screens (such as split screen and desktop windowing), developers should build Android apps that adapt to any screen and window size, regardless of device orientation. Paradigms like restricting orientation and resizability are too restrictive in today's multidevice world.

Ignore orientation, resizability, and aspect ratio restrictions

For apps targeting Android 16, Android 16 includes changes to how the system manages orientation, resizability, and aspect ratio restrictions. On displays with smallest width >= 600dp, the restrictions no longer apply. Apps also fill the entire display window, regardless of aspect ratio or a user's preferred orientation, and pillarboxing isn't used.

This change introduces a new standard platform behavior. Android is moving toward a model where apps are expected to adapt to various orientations, display sizes, and aspect ratios. Restrictions like fixed orientation or limited resizability hinder app adaptability, so we recommend making your app adaptive to deliver the best possible user experience.

You can also test this behavior by using the [app compatibility framework][a16-kilo-14] and enabling the UNIVERSAL_RESIZABLE_BY_DEFAULT compat flag.

Important: If you encounter a bug preventing these changes from being applied in the Android Studio emulator, use the prescribed workaround until the fix is released in Beta 2.

Common breaking changes

Ignoring orientation, resizability, and aspect ratio restrictions might impact your app's UI on some devices, especially elements that were designed for small layouts locked in portrait orientation: for example, issues like stretched layouts and off-screen animations and components. Any assumptions about aspect ratio or orientation can cause visual issues with your app. Learn more about how to avoid them and improve your app's adaptive behaviour.

Allowing device rotation results in more activity re-creation, which can result in losing user state if not properly preserved. Learn how to correctly save UI state in Save UI states.

Implementation details

The following manifest attributes and runtime APIs are ignored across large screen devices in full-screen and multi-window modes:

• screenOrientation
• resizableActivity
• minAspectRatio
• maxAspectRatio
• setRequestedOrientation()
• getRequestedOrientation()

The following values for screenOrientation, setRequestedOrientation(), and getRequestedOrientation() are ignored:

• portrait
• reversePortrait
• sensorPortrait
• userPortrait
• landscape
• reverseLandscape
• sensorLandscape
• userLandscape

Regarding display resizability, android:resizeableActivity="false", android:minAspectRatio, and android:maxAspectRatio have no effect.

For apps targeting Android 16, app orientation, resizability, and aspect ratio constraints are ignored on large screens by default, but every app that isn't fully ready can temporarily override this behavior by opting out (which results in the previous behavior of being placed in compatibility mode).

Exceptions

The Android 16 orientation, resizability, and aspect ratio restrictions don't apply in the following situations:

• Games (based on the android:appCategory flag)
• Users explicitly opting in to the app's default behavior in aspect ratio settings of the device
• Screens that are smaller than sw600dp

Opt out temporarily

To opt out a specific activity, declare the PROPERTY_COMPAT_ALLOW_RESTRICTED_RESIZABILITY manifest property:

<activity ...>
  <property android:name="android.window.PROPERTY_COMPAT_ALLOW_RESTRICTED_RESIZABILITY" android:value="true" />
  ...
</activity>

If too many parts of your app aren't ready for Android 16, you can opt out completely by applying the same property at the application level:

<application ...>
  <property android:name="android.window.PROPERTY_COMPAT_ALLOW_RESTRICTED_RESIZABILITY" android:value="true" />
</application>

Important: The opt-out is temporary and won't apply when targeting API level 37 in a future Android release. That is, for apps targeting API level 37, orientation, resizability, and aspect ratio restrictions are ignored on displays that are at least sw600dp.

健康与健身

Android 16 包含与健康与健身数据相关的以下变更。

健康与健身权限

For apps targeting Android 16 or higher, BODY_SENSORS permissions are transitioning to the granular permissions under android.permissions.health also used by Health Connect. Any API previously requiring BODY_SENSORS or BODY_SENSORS_BACKGROUND now requires the corresponding android.permissions.health permission. This affects the following data types, APIs, and foreground service types:

• HEART_RATE_BPM from Wear Health Services
• Sensor.TYPE_HEART_RATE from Android Sensor Manager
• heartRateAccuracy and heartRateBpm from Wear ProtoLayout
• FOREGROUND_SERVICE_TYPE_HEALTH where the respective android.permission.health permission is needed in place of BODY_SENSORS

If your app uses these APIs, it should now request the respective granular permissions:

• For while-in-use monitoring of Heart Rate, SpO2, or Skin Temperature: request the granular permission under android.permissions.health, such as READ_HEART_RATE instead of BODY_SENSORS.
• For background sensor access: request READ_HEALTH_DATA_IN_BACKGROUND instead of BODY_SENSORS_BACKGROUND.

These permissions are the same as those that guard access to reading data from Health Connect, the Android datastore for health, fitness, and wellness data.