Android 17 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 17 上运行的 所有应用,
无论其采用哪种 targetSdkVersion 都不例外。您应该测试您的应用,然后根据需要酌情修改,以便支持这些变更。
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 。
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|allam memory-limiter manual <pid> <limit>|max|noneam memory-limiter status
ignoreInstructs 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) ornone(do not ignore any apps). Passingnoneoverrides any previous calls toam 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.manualInstructs 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
30specifies that the process is limited to 30 MB of memory. Passingmaxremoves all memory limits on that process. Passingnoneremoves any manual limits set on the process, restoring the system's default limit (if any).statusReports 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 包含以下变更,旨在提升用户隐私保护。
短信 OTP 保护
从 Android 17 开始,Android 将扩大对包含一次性密码 (OTP) 的短信的保护范围。
在之前的 Android 版本中,此保护主要侧重于 SMS Retriever 格式。对于大多数应用,包含 SMS Retriever 哈希的消息的递送延迟了 3 小时。不过,某些应用(例如默认短信处理程序)不受此延迟的影响,拥有哈希的应用也不受此延迟的影响。
从 Android 17 开始,此保护也适用于 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),则该应用在收到消息后 3 小时内无法访问该消息。此变更旨在提高用户安全性,确保只有与消息中提及的网域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,系统会保留 SMS_RECEIVED_ACTION 广播,并过滤 短信提供商 数据库查询。延迟结束后,这些应用即可使用短信。此变更适用于
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、关联设备配套应用等)不受此延迟的影响。所有依赖于读取短信 来提取 OTP 的应用都应过渡到使用 SMS Retriever 或 SMS User Consent API,以确保功能持续可用。
安全
Android 17 包含以下改进,旨在提升设备和应用安全性。
usesClearTraffic 弃用计划
我们计划在未来的版本中弃用 usesCleartextTraffic 元素。需要建立未加密 (HTTP) 连接的应用应迁移为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,网络安全配置文件仅在 API 级别 24 及更高版本中受支持。如果您的应用的最低 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,您可以使用网络配置文件,而无需设置 usesCleartextTraffic。
限制隐式 URI 授予
Currently, if an app launches an intent with a URI that has the action
ACTION_SEND, ACTION_SEND_MULTIPLE, or
ACTION_IMAGE_CAPTURE, the system automatically grants the read and
write URI permissions to the target app. Starting in Android 18, the system will
no longer automatically grant these permissions. For this reason, we recommend
that apps explicitly grant the
relevant URI permissions instead of relying on the system to grant them.
To detect the usage of these intents in your app, use StrictMode with
detectImplicitUriPermissionGrant() to trigger a violation:
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);
Alternatively, you can monitor for logged exceptions containing the message
Please set the grant explicitly in the app that appears when system implicitly
sets the grant. You can monitor for these logs
using the following adb command:
adb logcat | grep "Please set the grant explicitly in the app"
To explicitly grant the necessary permissions, add the
FLAG_GRANT_READ_URI_PERMISSION flag to ACTION_SEND and
ACTION_SEND_MULTIPLE intents:
Kotlin
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
Java
intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
Include both FLAG_GRANT_READ_URI_PERMISSION and
FLAG_GRANT_WRITE_URI_PERMISSION flags for
ACTION_IMAGE_CAPTURE intents:
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 newERROR_TOO_MANY_KEYSvalue. - All other apps:
getNumericErrorCode()returnsERROR_INCORRECT_USAGE.
阻止跨资料环回流量
从 Android 17 开始,默认情况下不再允许跨个人资料环回流量。同一个人资料内的环回流量不受影响。 此项变更适用于在 Android 17 或更高版本上运行的所有应用,无论应用以哪个 API 级别为目标平台。
用户体验和系统界面
Android 17 包含以下变更,旨在打造更加一致、直观的用户体验。
在旋转后恢复默认 IME 可见性
Beginning with Android 17, when the device's configuration changes (for example, through rotation), and this is not handled by the app itself, the previous IME visibility is not restored.
If your app undergoes a configuration change that it does not handle, and the app needs the keyboard to be visible after the change, you must explicitly request this. You can make this request in one of the following ways:
- Set the
android:windowSoftInputModeattribute tostateAlwaysVisible. - Programmatically request the soft keyboard in your activity's
onCreate()method, or add theonConfigurationChanged()method.
人工干预
Android 17 包含以下变更,这些变更会影响应用与键盘和触控板等人工输入设备的互动方式。
在指针捕获期间,触控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。
后台音频安全加固
从 Android 17 开始,音频框架会对后台音频互动(包括音频播放、音频焦点请求和音量更改 API)强制执行限制,以确保这些更改是由用户有意发起的。
如果应用尝试在应用未处于有效生命周期时调用音频 API,则音频播放和音量更改 API 会以静默方式失败,而不会抛出异常或提供失败消息。音频焦点 API 会失败,并返回结果代码 AUDIOFOCUS_REQUEST_FAILED。
如需了解详情(包括缓解措施),请参阅后台音频安全加固。
连接
Android 17 包含以下变更,旨在提升设备连接。
在蓝牙绑定丢失时自动重新配对
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 allowing the system to re-establish bonds in the background without requiring 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_REQUESTnow includes theEXTRA_PAIRING_CONTEXTextra 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_MISSINGintent 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