Android 17 平台包含一些可能会影响您的应用的行为变更。以下行为变更将影响在 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。
安全
Android 17 包含以下设备和应用安全方面的改进。
usesClearTraffic 弃用计划
In a future release, we plan to deprecate the usesCleartextTraffic element.
Apps that need to make unencrypted (HTTP) connections should migrate to
using a network security configuration file, which lets you
specify which domains your app needs to make cleartext connections to.
Be aware that network security configuration files are only supported on API levels 24 and higher. If your app has a minimum API level lower than 24, you should do both of the following:
- Set the
usesCleartextTrafficattribute totrue - Use a network configuration file
If your app's minimum API level is 24 or higher, you can use a network
configuration file and you don't need to set usesCleartextTraffic.
限制隐式 URI 授权
Currently, if an app launches an intent with a URI that has the action Send,
SendMultiple, or ImageCapture, the system automatically grants the read and
write URI permissions to the target app. We plan to change this behavior in
Android 18. For this reason, we recommend that apps explicitly
grant the relevant URI permissions instead of relying on the system to grant
them.
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 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 or higher:
getNumericErrorCode()returns the newERROR_TOO_MANY_KEYSvalue. - All other apps:
getNumericErrorCode()returnsERROR_INCORRECT_USAGE.
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。
在旋转后恢复默认 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。
如果应用经历了它无法处理的配置更改，并且应用需要在更改后显示键盘，您必须明确请求此行为。您可以通过以下方式之一提出此要求：
- 将
android:windowSoftInputMode属性设置为stateAlwaysVisible。 - 在 activity 的
onCreate()方法中以编程方式请求显示软键盘，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，触控板默认传递相对事件
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 针对媒体行为做了以下更改。
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.
For more information, including mitigation strategies, see Background audio hardening.