行为变更：所有应用

Android 17 平台包含一些可能会影响您的应用的行为变更。以下行为变更会影响在 Android 17 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，以适当地支持这些变更。

此外，请务必查看仅影响以 Android 17 为目标平台的应用的行为变更列表。

注意：本页面列出了一些较为重要的变更。如需了解详情，请参阅 Android 17 版本说明。

核心功能

Android 17（API 级别 37）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。

应用内存限制

Android 17 introduces app memory limits based on the device's total RAM to create a more stable and deterministic environment for your apps and Android users. These limits focus on memory leaks and other outliers before they trigger system-wide instability resulting in UI stuttering, higher battery drain, and apps being killed. While we anticipate minimal impact on the vast majority of app sessions, we recommend the following memory best practices, including establishing a baseline for memory.

You can determine if your app session was impacted by calling getDescription in ApplicationExitInfo; if your app was affected, the exit reason will be REASON_OTHER and the description will contain the string "MemoryLimiter:AnonSwap" along with other information. You can also use trigger-based profiling with TRIGGER_TYPE_ANOMALY to get heap dumps that are collected when the memory limit is hit.

The Manage your app's memory documentation gives information to help you diagnose your app's memory issues and optimize its resource consumption.

Test your app's behavior under the memory constraints

You can use Android Debug Bridge (adb) to adjust or disable the memory limits on any device that imposes them. The shell command am provides three subcommands to adjust the memory limits. (These commands have no effect on a device which does not impose memory limits.)

• am memory-limiter ignore <uid>|none|all
• am memory-limiter manual <pid> <limit>|max|none
• am memory-limiter status

ignore

Instructs the memory limiter to ignore some or all processes. Passing a UID (Android User ID) instructs the memory limiter to ignore enforcement on all processes associated with that UID. You can also pass all (ignore all apps) or none (do not ignore any apps). Passing none overrides any previous calls to am memory-limiter ignore.

If you instruct the memory limiter to ignore a UID, you can still apply a manual memory limit to a process within the app by calling am memory-limiter manual.

manual

Instructs the system to impose a memory constraint on the process with the specified PID (Process ID). The memory constraint is specified as an integer number of MB; for example, passing 30 specifies that the process is limited to 30 MB of memory. Passing max removes all memory limits on that process. Passing none removes any manual limits set on the process, restoring the system's default limit (if any).

status

Reports the current status of the memory limiter. The status includes the memory limits imposed on visible and non-visible processes.

隐私权

Android 17 包含以下旨在提升用户隐私保护水平的变更。

短信动态密码保护

从 Android 17 开始，Android 将扩大对包含动态密码 (OTP) 的短信的保护范围。

在之前的 Android 版本中，此保护机制主要针对 SMS Retriever 格式。对于大多数应用，包含短信检索器哈希的消息延迟了 3 小时才送达。不过，某些应用（例如默认短信处理程序）不受延迟影响，拥有哈希的应用也不受延迟影响。

从 Android 17 开始，此保护措施也适用于 WebOTP 格式的消息。如果应用有权读取短信，但不是 WebOTP 消息的预期接收者（由网域验证确定），则应用在收到消息 3 小时后才能访问该消息。此项变更旨在提高用户安全性，确保只有与消息中提及的网域相关联的应用才能以编程方式读取验证码。

在这 3 小时的延迟期间，SMS_RECEIVED_ACTION 广播会被扣留，短信提供程序数据库查询会被过滤。延迟后，这些应用便可收到短信。此项变更适用于所有应用，无论其目标 API 级别如何。

某些应用（例如默认短信助理应用、已连接设备的配套应用等）不受此延迟的影响。所有依赖读取短信来提取动态密码的应用都应改用 SMS Retriever 或 SMS User Consent API，以确保功能正常运行。

注意： 如果您的应用以 Android 17（API 级别 37）或更高版本为目标平台，此保护措施也会扩展到标准短信。如需了解详情，请参阅行为变更：以 Android 17 为目标平台的应用文档中的针对标准短信的动态密码保护。

安全

Android 17 对设备和应用安全性进行了以下改进。

usesClearTraffic 弃用计划

在未来发布的版本中，我们计划弃用 usesCleartextTraffic 元素。 需要建立未加密 (HTTP) 连接的应用应迁移到使用网络安全配置文件，该文件可让您指定应用需要与哪些网域建立明文连接。

请注意，只有 API 级别 24 及更高级别支持网络安全配置文件。如果应用的最低 API 级别低于 24，您应执行以下两项操作：

• 将 usesCleartextTraffic 属性设置为 true
• 使用网络配置文件

如果应用的最低 API 级别为 24 或更高级别，您可以使用网络配置文件，而无需设置 usesCleartextTraffic。

限制隐式 URI 授权

目前，如果应用启动具有操作 ACTION_SEND、ACTION_SEND_MULTIPLE 或 ACTION_IMAGE_CAPTURE 的 URI 的 intent，系统会自动向目标应用授予读取和写入 URI 权限。从 Android 18 开始，系统将不再自动授予这些权限。因此，我们建议应用明确授予相关 URI 权限，而不是依赖系统来授予这些权限。

如需检测应用中这些 intent 的使用情况，请将 StrictMode 与 detectImplicitUriPermissionGrant() 搭配使用，以触发违规行为：

Kotlin

val policy = StrictMode.VmPolicy.Builder()
    .detectImplicitUriPermissionGrant()
    .penaltyLog()
    .build()
StrictMode.setVmPolicy(policy)

Java

StrictMode.VmPolicy policy = new StrictMode.VmPolicy.Builder()
    .detectImplicitUriPermissionGrant()
    .penaltyLog()
    .build();
StrictMode.setVmPolicy(policy);

或者，您也可以监控记录的异常，其中包含系统隐式设置授权时显示的消息 Please set the grant explicitly in the app。您可以使用以下 adb 命令监控这些日志：

adb logcat | grep "Please set the grant explicitly in the app"

如需明确授予必要的权限，请将 FLAG_GRANT_READ_URI_PERMISSION 标志添加到 ACTION_SEND 和 ACTION_SEND_MULTIPLE intent：

Kotlin

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)

Java

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);

为 ACTION_IMAGE_CAPTURE intent 添加 FLAG_GRANT_READ_URI_PERMISSION 和 FLAG_GRANT_WRITE_URI_PERMISSION 标志：

Kotlin

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION or Intent.FLAG_GRANT_WRITE_URI_PERMISSION)

Java

intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION | Intent.FLAG_GRANT_WRITE_URI_PERMISSION);

每个应用的密钥库限制

Apps should avoid creating excessive numbers of keys in Android Keystore, because it is a shared resource for all apps on the device. Beginning with Android 17, the system enforces a limit on the number of keys an app can own. The limit is 50,000 keys for non-system apps targeting Android 17 (API level 37) or higher, and 200,000 keys for all other apps. System apps have a limit of 200,000 keys, regardless of which API level they target.

If an app attempts to create keys beyond the limit, the creation fails with a KeyStoreException. The exception's message string contains information about the key limit. If the app calls getNumericErrorCode() on the exception, the return value depends on what API level the app targets:

• Apps targeting Android 17 (API level 37) or higher: getNumericErrorCode() returns the new ERROR_TOO_MANY_KEYS value.
• All other apps: getNumericErrorCode() returns ERROR_INCORRECT_USAGE.

屏蔽跨资料环回流量

从 Android 17 开始，默认情况下不再允许跨资料环回流量。同一配置文件内的环回流量不受影响。 此变更适用于在 Android 17 或更高版本上运行的所有应用，无论应用的目标 API 级别如何。

用户体验和系统界面

Android 17 包含以下变更，旨在打造更一致、更直观的用户体验。

旋转后恢复默认 IME 可见性

从 Android 17 开始，当设备的配置发生变化（例如，通过旋转）且应用本身未处理此变化时，系统不会恢复之前的 IME 可见性。

如果您的应用发生其无法处理的配置更改，并且应用需要在更改后显示键盘，您必须明确请求显示键盘。您可以通过以下任一方式提出此请求：

• 将 android:windowSoftInputMode 属性设置为 stateAlwaysVisible。
• 在 activity 的 onCreate() 方法中以编程方式请求软键盘，或添加 onConfigurationChanged() 方法。

人工输入

Android 17 包含以下变更，这些变更会影响应用与键盘和触摸板等人机输入设备的交互方式。

在指针捕获期间，触摸板默认提供相对事件

Beginning with Android 17, if an app requests pointer capture using View.requestPointerCapture() and the user uses a touchpad, the system recognizes pointer movement and scrolling gestures from the user's touches and reports them to the app in the same way as pointer and scroll wheel movements from a captured mouse. In most cases, this removes the need for apps that support captured mice to add special handling logic for touchpads. For more details, see the documentation for View.POINTER_CAPTURE_MODE_RELATIVE.

Previously, the system did not attempt to recognize gestures from the touchpad, and instead delivered the raw, absolute finger locations to the app in a similar format to touchscreen touches. If an app still requires this absolute data, it should call the new View.requestPointerCapture(int) method with View.POINTER_CAPTURE_MODE_ABSOLUTE instead.

媒体

Android 17 包含以下媒体行为变更。

后台音频强化

Beginning with Android 17, the audio framework enforces restrictions on background audio interactions including audio playback, audio focus requests, and volume change APIs to ensure that these changes are started intentionally by the user.

If the app tries to call audio APIs while the app is not in a valid lifecycle, the audio playback and volume change APIs fail silently without throwing an exception or providing a failure message. The audio focus API fails with the result code AUDIOFOCUS_REQUEST_FAILED.

Note: The restrictions are more stringent if an app targets Android 17 (API level 37). For these apps, the foreground service must have while-in-use (WIU) capabilities, unless the app has the exact alarm permission and is interacting with USAGE_ALARM audio streams.

For more information, including mitigation strategies, see Background audio hardening.

连接

Android 17 包含以下旨在增强设备连接性的变更。

针对蓝牙绑定丢失自主发起重新配对

Android 17 introduces autonomous re-pairing, a system-level enhancement designed to automatically resolve Bluetooth bond loss.

Previously, if a bond was lost, users had to manually navigate to Settings to unpair and then re-pair the peripheral. This feature builds upon the security improvement of Android 16 by enabling the system to re-establish bonds after user consent is granted. This eliminates the need for users to manually navigate to Settings to unpair and re-pair peripherals.

While most apps will not require code changes, developers should be aware of the following behavior changes in Bluetooth stack:

• New pairing context: The ACTION_PAIRING_REQUEST now includes the EXTRA_PAIRING_CONTEXT extra which allows apps to distinguish between a standard pairing request and an autonomous system-initiated re-pairing attempt.
• Conditional key updates: Existing security keys will only be replaced if the re-pairing is successful and new connection meets or exceeds the security level of the previous bond.
• Modified intent timing: The ACTION_KEY_MISSING intent is now broadcast only if the autonomous re-pairing attempt fails. This reduces unnecessary error handling in the app if the system successfully recovers the bond in the background.
• User notification: The system manages re-pairing via new UI notifications and dialogs. Users will be prompted to confirm the re-pairing attempt to ensure they are aware of the reconnection.

Peripheral device manufacturers and companion app developers should verify that hardware and app gracefully handle bond transitions. To test this behavior, simulate a remote bond loss using either of the following methods:

• Manually remove the bond information from the peripheral device
• Manually unpair the device in: Settings > Connected devices