行为变更:以 Android 16 或更高版本为目标平台的应用

与之前的版本一样,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(API 级别 36)包含以下变更,旨在打造更一致、更直观的用户体验。

无边框设计选择退出功能即将停用

Android 15 enforced edge-to-edge for apps targeting Android 15 (API level 35), but your app could opt-out by setting R.attr#windowOptOutEdgeToEdgeEnforcement to true. For apps targeting Android 16 (API level 36), R.attr#windowOptOutEdgeToEdgeEnforcement is deprecated and disabled, and your app can't opt-out of going edge-to-edge.

  • If your app targets Android 16 (API level 36) and is running on an Android 15 device, R.attr#windowOptOutEdgeToEdgeEnforcement continues to work.
  • If your app targets Android 16 (API level 36) and is running on an Android 16 device, R.attr#windowOptOutEdgeToEdgeEnforcement is disabled.

For testing in Android 16, ensure your app supports edge-to-edge and remove any use of R.attr#windowOptOutEdgeToEdgeEnforcement so that your app also supports edge-to-edge on an Android 15 device. To support edge-to-edge, see the Compose and Views guidance.

预测性返回需要迁移或选择停用

For apps targeting Android 16 (API level 36) or higher and running on an Android 16 or higher device, the predictive back system animations (back-to-home, cross-task, and cross-activity) are enabled by default. Additionally, onBackPressed is not called and KeyEvent.KEYCODE_BACK is not dispatched anymore.

If your app intercepts the back event and you haven't migrated to predictive back yet, update your app to use supported back navigation APIs, or temporarily opt out by setting the android:enableOnBackInvokedCallback attribute to false in the <application> or <activity> tag of your app's AndroidManifest.xml file.

The predictive back-to-home animation.
The predictive cross-activity animation.
The predictive cross-task animation.

优雅字体 API 已弃用并停用

以 Android 15(API 级别 35)为目标平台的应用默认将 elegantTextHeight TextView 属性设置为 true,从而将紧凑型字体替换为可读性更高的字体。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,当您的应用以 Android 16 为目标平台后,系统会忽略该属性。由这些 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、泰卢固语或泰语文本的呈现效果一致且不受未来变化的影响。

针对以 Android 14(API 级别 34)及更低版本为目标平台的应用,或针对以 Android 15(API 级别 35)为目标平台且通过将 elegantTextHeight 属性设置为 false 替换默认值的应用,
elegantTextHeight 行为。
以 Android 16(API 级别 36)为目标平台的应用,或以 Android 15(API 级别 35)为目标平台但未通过将 elegantTextHeight 属性设置为 false 来替换默认值的应用,其
elegantTextHeight 行为。

核心功能

Android 16(API 级别 36)包含以下变更,这些变更会修改或扩展 Android 系统的各种核心功能。

固定费率工作安排优化

Prior to targeting Android 16, when scheduleAtFixedRate missed a task execution due to being outside a valid process lifecycle, all missed executions immediately execute when the app returns to a valid lifecycle.

When targeting Android 16, at most one missed execution of scheduleAtFixedRate is immediately executed when the app returns to a valid lifecycle. This behavior change is expected to improve app performance. Test this behavior in your app to check if your app is impacted. You can also test by using the app compatibility framework and enabling the STPE_SKIP_MULTIPLE_MISSED_PERIODIC_TASKS compat flag.

设备规格

Android 16(API 级别 36)在应用显示在大屏设备上时,包含以下变更。

自适应布局

现在,Android 应用可在各种设备(例如手机、平板电脑、可折叠设备、桌面设备、汽车和电视)上运行,并且在大屏设备上支持多种窗口模式(例如分屏和桌面窗口),因此开发者应构建能够适应任何屏幕和窗口尺寸的 Android 应用,无论设备方向如何。在当今多设备的世界中,限制屏幕方向和尺寸可调整性等范式过于严格。

忽略屏幕方向、尺寸可调整性和宽高比限制

对于以 Android 16(API 级别 36)为目标平台的应用,Android 16 包含对系统管理屏幕方向、尺寸调整能力和宽高比限制的方式的变更。在最小宽度 >= 600dp 的显示屏上,这些限制不再适用。应用还会填满整个显示窗口,无论宽高比或用户偏好的屏幕方向如何,都不会使用竖条模式。

此变更引入了新的标准平台行为。Android 正在向一种模型转变,在该模型中,应用需要适应各种屏幕方向、显示大小和宽高比。固定屏幕方向或有限的尺寸可调整性等限制会阻碍应用的自适应能力,因此我们建议让应用具备自适应能力,以尽可能提供最佳的用户体验。

您还可以使用应用兼容性框架并启用 UNIVERSAL_RESIZABLE_BY_DEFAULT 兼容性标志来测试此行为。

常见的重大更改

忽略屏幕方向、可调整大小性和宽高比限制可能会影响应用在某些设备上的界面,尤其是那些专为锁定为纵向的小布局设计的元素,例如布局拉伸、动画和组件超出屏幕等问题。任何关于宽高比或屏幕方向的假设都可能导致应用出现视觉问题。详细了解如何避免这些问题并改进应用的自适应行为。

允许设备旋转会导致更多 activity 重新创建,如果未正确保留用户状态,可能会导致用户状态丢失。如需了解如何正确保存界面状态,请参阅保存界面状态

实现细节

在全屏模式和多窗口模式下,以下清单属性和运行时 API 会被大屏设备忽略:

系统会忽略 screenOrientationsetRequestedOrientation()getRequestedOrientation() 的以下值:

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

对于显示屏可调整大小性,android:resizeableActivity="false"android:minAspectRatioandroid:maxAspectRatio 没有影响。

对于以 Android 16(API 级别 36)为目标平台的应用,默认情况下,大屏设备会忽略应用屏幕方向、可调整尺寸性和宽高比限制,但尚未完全准备就绪的每个应用都可以选择停用此行为,从而暂时替换此行为(这会导致应用采用之前的行为,即置于兼容模式)。

异常

在以下情况下,Android 16 的屏幕方向、尺寸调整能力和宽高比限制不适用:

  • 游戏(基于 android:appCategory 标志)
  • 用户在设备的宽高比设置中明确选择启用应用的默认行为
  • 小于 sw600dp 的屏幕

暂时停用

如需选择停用特定 activity,请声明 PROPERTY_COMPAT_ALLOW_RESTRICTED_RESIZABILITY 清单属性:

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

如果您的应用有太多部分尚未准备好支持 Android 16,您可以在应用级别应用相同的属性,从而完全选择不启用该功能:

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

健康与健身

Android 16(API 级别 36)包含与健康和健身数据相关的以下变更。

健康与健身权限

For apps targeting Android 16 (API level 36) or higher, BODY_SENSORS permissions use more granular permissions under android.permissions.health, which Health Connect also uses. As of Android 16, any API previously requiring BODY_SENSORS or BODY_SENSORS_BACKGROUND requires the corresponding android.permissions.health permission instead. This affects the following data types, APIs, and foreground service types:

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

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.

Mobile apps

Mobile apps migrating to use the READ_HEART_RATE and other granular permissions must also declare an activity to display the app's privacy policy. This is the same requirement as Health Connect.

连接

Android 16(API 级别 36)在蓝牙堆栈中进行了以下更改,以改善与外围设备的连接。

用于处理绑定丢失和加密更改的新 intent

作为改进了对键值对丢失的处理的一部分,Android 16 还引入了 2 个新 intent,以便应用更好地了解键值对丢失和加密更改。

以 Android 16 为目标平台的应用现在可以:

  • 在检测到远程键盘连接丢失时接收 ACTION_KEY_MISSING intent,以便提供更具信息量的用户反馈并采取适当的措施。
  • 每当链接的加密状态发生变化时,都会收到 ACTION_ENCRYPTION_CHANGE intent。这包括加密状态更改、加密算法更改和加密密钥大小更改。如果应用在稍后收到 ACTION_ENCRYPTION_CHANGE intent 时成功加密了链接,则必须将该绑定视为已恢复。

适应不同的 OEM 实现

虽然 Android 16 引入了这些新 intent,但其实现和广播可能会因不同的设备制造商 (OEM) 而异。为了确保您的应用在所有设备上都能提供一致且可靠的体验,开发者应设计其绑定丢失处理机制,以妥善适应这些潜在的变化。

我们建议您采用以下应用行为:

  • 如果广播 ACTION_KEY_MISSING intent:

    系统会断开 ACL(异步无连接)链接,但会保留设备的配对信息(如此处所述)。

    您的应用应将此 intent 用作检测配对丢失的主要信号,并在发起设备忘记或重新配对之前引导用户确认远程设备是否在范围内。

    如果设备在收到 ACTION_KEY_MISSING 后断开连接,您的应用应谨慎重新连接,因为设备可能已不再与系统绑定。

  • 如果未广播 ACTION_KEY_MISSING intent:

    ACL 链接将保持连接状态,系统会移除设备的配对信息,与 Android 15 中的行为相同。

    在这种情况下,您的应用应继续使用与之前的 Android 版本相同的现有配对丢失处理机制,以检测和管理配对丢失事件。

移除蓝牙绑定的新方式

All apps targeting Android 16 are now able to unpair bluetooth devices using a public API in CompanionDeviceManager. If a companion device is being managed as a CDM association, then the app can trigger bluetooth bond removal by using the new removeBond(int) API on the associated device. The app can monitor the bond state changes by listening to the bluetooth device broadcast event ACTION_BOND_STATE_CHANGED.

安全

Android 16(API 级别 36)包含以下安全方面的变更。

MediaStore 版本锁定

对于以 Android 16 或更高版本为目标平台的应用,MediaStore#getVersion() 现在将是每个应用的唯一标识。这会从版本字符串中移除标识属性,以防止滥用和用于指纹识别技术。应用不应对此版本的格式做出任何假设。在使用此 API 时,应用应已处理版本变更,并且在大多数情况下无需更改其当前行为,除非开发者尝试推断超出此 API 预期范围的其他信息。

更安全的 intent

The Safer Intents feature is a multi-phase security initiative designed to improve the security of Android's intent resolution mechanism. The goal is to protect apps from malicious actions by adding checks during intent processing and filtering intents that don't meet specific criteria.

In Android 15 the feature focused on the sending app, now with Android 16, shifts control to the receiving app, allowing developers to opt-in to strict intent resolution using their app manifest.

Two key changes are being implemented:

  1. Explicit Intents Must Match the Target Component's Intent Filter: If an intent explicitly targets a component, it should match that component's intent filter.

  2. Intents Without an Action Cannot Match any Intent Filter: Intents that don't have an action specified shouldn't be resolved to any intent filter.

These changes only apply when multiple apps are involved and don't affect intent handling within a single app.

Impact

The opt-in nature means that developers must explicitly enable it in their app manifest for it to take effect. As a result, the feature's impact will be limited to apps whose developers:

  • Are aware of the Safer Intents feature and its benefits.
  • Actively choose to incorporate stricter intent handling practices into their apps.

This opt-in approach minimizes the risk of breaking existing apps that may rely on the current less-secure intent resolution behavior.

While the initial impact in Android 16 may be limited, the Safer Intents initiative has a roadmap for broader impact in future Android releases. The plan is to eventually make strict intent resolution the default behavior.

The Safer Intents feature has the potential to significantly enhance the security of the Android ecosystem by making it more difficult for malicious apps to exploit vulnerabilities in the intent resolution mechanism.

However, the transition to opt-out and mandatory enforcement must be carefully managed to address potential compatibility issues with existing apps.

Implementation

Developers need to explicitly enable stricter intent matching using the intentMatchingFlags attribute in their app manifest. Here is an example where the feature is opt-in for the entire app, but disabled/opt-out on a receiver:

<application android:intentMatchingFlags="enforceIntentFilter">
    <receiver android:name=".MyBroadcastReceiver" android:exported="true" android:intentMatchingFlags="none">
        <intent-filter>
            <action android:name="com.example.MY_CUSTOM_ACTION" />
        </intent-filter>
        <intent-filter>
            <action android:name="com.example.MY_ANOTHER_CUSTOM_ACTION" />
        </intent-filter>
    </receiver>
</application>

More on the supported flags:

Flag Name Description
enforceIntentFilter Enforces stricter matching for incoming intents
none Disables all special matching rules for incoming intents. When specifying multiple flags, conflicting values are resolved by giving precedence to the "none" flag
allowNullAction Relaxes the matching rules to allow intents without an action to match. This flag to be used in conjunction with "enforceIntentFilter" to achieve a specific behavior

Testing and Debugging

When the enforcement is active, apps should function correctly if the intent caller has properly populated the intent. However, blocked intents will trigger warning log messages like "Intent does not match component's intent filter:" and "Access blocked:" with the tag "PackageManager." This indicates a potential issue that could impact the app and requires attention.

Logcat filter:

tag=:PackageManager & (message:"Intent does not match component's intent filter:" | message: "Access blocked:")

GPU 系统调用过滤

To harden the Mali GPU surface, Mali GPU IOCTLs that have been deprecated or are intended solely for GPU development have been blocked in production builds. Additionally, IOCTLs used for GPU profiling have been restricted to the shell process or debuggable applications. Refer to the SAC update for more details on the platform-level policy.

This change takes place on Pixel devices using the Mali GPU (Pixel 6-9). Arm has provided official categorization of their IOCTLs in Documentation/ioctl-categories.rst of their r54p2 release. This list will continue to be maintained in future driver releases.

This change does not impact supported graphics APIs (including Vulkan and OpenGL), and is not expected to impact developers or existing applications. GPU profiling tools such as the Streamline Performance Analyzer and the Android GPU Inspector won't be affected.

Testing

If you see a SELinux denial similar to the following, it is likely your application has been impacted by this change:

06-30 10:47:18.617 20360 20360 W roidJUnitRunner: type=1400 audit(0.0:85): avc:  denied  { ioctl }
for  path="/dev/mali0" dev="tmpfs" ino=1188 ioctlcmd=0x8023
scontext=u:r:untrusted_app_25:s0:c512,c768 tcontext=u:object_r:gpu_device:s0 tclass=chr_file
permissive=0 app=com.google.android.selinux.pts

If your application needs to use blocked IOCTLs, please file a bug and assign it to android-partner-security@google.com.

FAQ

  1. Does this policy change apply to all OEMs? This change will be opt-in, but available to any OEMs who would like to use this hardening method. Instructions for implementing the change can be found in the implementation documentation.

  2. Is it mandatory to make changes in the OEM codebase to implement this, or does it come with a new AOSP release by default? The platform-level change will come with a new AOSP release by default. Vendors may opt-in to this change in their codebase if they would like to apply it.

  3. Are SoCs responsible for keeping the IOCTL list up to date? For example, if my device uses an ARM Mali GPU, would I need to reach out to ARM for any of the changes? Individual SoCs must update their IOCTL lists per device upon driver release. For example, ARM will update their published IOCTL list upon driver updates. However, OEMs should make sure that they incorporate the updates in their SEPolicy, and add any selected custom IOCTLs to the lists as needed.

  4. Does this change apply to all Pixel in-market devices automatically, or is a user action required to toggle something to apply this change? This change applies to all Pixel in-market devices using the Mali GPU (Pixel 6-9). No user action is required to apply this change.

  5. Will use of this policy impact the performance of the kernel driver? This policy was tested on the Mali GPU using GFXBench, and no measurable change to GPU performance was observed.

  6. Is it necessary for the IOCTL list to align with the current userspace and kernel driver versions? Yes, the list of allowed IOCTLs must be synchronized with the IOCTLs supported by both the userspace and kernel drivers. If the IOCTLs in the user space or kernel driver are updated, the SEPolicy IOCTL list must be updated to match.

  7. ARM has categorized IOCTLs as 'restricted' / 'instrumentation', but we want to use some of them in production use-cases, and/or deny others. Individual OEMs/SoCs are responsible for deciding on how to categorize the IOCTLs they use, based on the configuration of their userspace Mali libraries. ARM's list can be used to help decide on these, but each OEM/SoC's use-case may be different.

隐私权

Android 16(API 级别 36)包含以下隐私权方面的变更。

本地网络权限

Devices on the LAN can be accessed by any app that has the INTERNET permission. This makes it easy for apps to connect to local devices but it also has privacy implications such as forming a fingerprint of the user, and being a proxy for location.

The Local Network Protections project aims to protect the user's privacy by gating access to the local network behind a new runtime permission.

Release plan

This change will be deployed between two releases, 25Q2 and 26Q2 respectively. It is imperative that developers follow this guidance for 25Q2 and share feedback because these protections will be enforced at a later Android release. Moreover, they will need to update scenarios which depend on implicit local network access by using the following guidance and prepare for user rejection and revocation of the new permission.

Impact

At the current stage, LNP is an opt-in feature which means only the apps that opt in will be affected. The goal of the opt-in phase is for app developers to understand which parts of their app depend on implicit local network access such that they can prepare to permission guard them for the next release.

Apps will be affected if they access the user's local network using:

  • Direct or library use of raw sockets on local network addresses (e.g. mDNS or SSDP service discovery protocol)
  • Use of framework level classes that access the local network (e.g. NsdManager)

Traffic to and from a local network address requires local network access permission. The following table lists some common cases:

App Low Level Network Operation Local Network Permission Required
Making an outgoing TCP connection yes
Accepting incoming TCP connections yes
Sending a UDP unicast, multicast, broadcast yes
Receiving an incoming UDP unicast, multicast, broadcast yes

These restrictions are implemented deep in the networking stack, and thus they apply to all networking APIs. This includes sockets created in native or managed code, networking libraries like Cronet and OkHttp, and any APIs implemented on top of those. Trying to resolve services on the local network (i.e. those with a .local suffix) will require local network permission.

Exceptions to the rules above:

  • If a device's DNS server is on a local network, traffic to or from it (at port 53) doesn't require local network access permission.
  • Applications using Output Switcher as their in-app picker won't need local network permissions (more guidance to come in 2025Q4).

Developer Guidance (Opt-in)

To opt into local network restrictions, do the following:

  1. Flash the device to a build with 25Q2 Beta 3 or later.
  2. Install the app to be tested.
  3. Toggle the Appcompat flag in adb:

    adb shell am compat enable RESTRICT_LOCAL_NETWORK <package_name>
    
  4. Reboot The device

Now your app's access to the local network is restricted and any attempt to access the local network will lead to socket errors. If you are using APIs that perform local network operations outside of your app process (ex: NsdManager), they won't be impacted during the opt-in phase.

To restore access, you must grant your app permission to NEARBY_WIFI_DEVICES.

  1. Ensure the app declares the NEARBY_WIFI_DEVICES permission in its manifest.
  2. Go to Settings > Apps > [Application Name] > Permissions > Nearby devices > Allow.

Now your app's access to the local network should be restored and all your scenarios should work as they did prior to opting the app in.

Once enforcement for local network protection begins, here is how the app network traffic will be impacted.

Permission Outbound LAN Request Outbound/Inbound Internet Request Inbound LAN Request
Granted Works Works Works
Not Granted Fails Works Fails

Use the following command to toggle-off the App-Compat flag

adb shell am compat disable RESTRICT_LOCAL_NETWORK <package_name>

Errors

Errors arising from these restrictions will be returned to the calling socket whenever it invokes send or a send variant to a local network address.

Example errors:

sendto failed: EPERM (Operation not permitted)

sendto failed: ECONNABORTED (Operation not permitted)

Local Network Definition

A local network in this project refers to an IP network that utilizes a broadcast-capable network interface, such as Wi-Fi or Ethernet, but excludes cellular (WWAN) or VPN connections.

The following are considered local networks:

IPv4:

  • 169.254.0.0/16 // Link Local
  • 100.64.0.0/10 // CGNAT
  • 10.0.0.0/8 // RFC1918
  • 172.16.0.0/12 // RFC1918
  • 192.168.0.0/16 // RFC1918

IPv6:

  • Link-local
  • Directly-connected routes
  • Stub networks like Thread
  • Multiple-subnets (TBD)

Additionally, both multicast addresses (224.0.0.0/4, ff00::/8) and the IPv4 broadcast address (255.255.255.255) are classified as local network addresses.

应用拥有的照片

When prompted for photo and video permissions by an app targeting SDK 36 or higher on devices running Android 16 or higher, users who choose to limit access to selected media will see any photos owned by the app pre-selected in the photo picker. Users can deselect any of these pre-selected items, which will revoke the app's access to those photos and videos.