行为变更：所有应用

Android 15 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 15 上运行的所有应用， 而不考虑 targetSdkVersion。您应该测试您的应用，然后修改 以适当地支持这些内容（如果适用）。

此外，请务必查看仅影响应用的行为变更列表 以 Android 15 为目标平台。

核心功能

Android 15 修改或扩展了 Android 系统的各种核心功能。

对软件包停止状态的更改

The intention of the package FLAG_STOPPED state (which users can engage in AOSP builds by long-pressing an app icon and selecting "Force Stop") has always been to keep apps in this state until the user explicitly removes the app from this state by directly launching the app or indirectly interacting with the app (through the sharesheet or a widget, selecting the app as live wallpaper, etc.). In Android 15, we are updating the behavior of the system to be aligned with this intended behavior. Apps should only be removed from the stopped state through direct or indirect user action.

To support the intended behavior, in addition to the existing restrictions, the system also cancels all pending intents when the app enters the stopped state on a device running Android 15. When the user's actions remove the app from the stopped state, the ACTION_BOOT_COMPLETED broadcast is delivered to the app providing an opportunity to re-register any pending intents.

Note: Apps use pending intents to update app widgets. If an app enters the stopped state, all these pending intents are canceled, and the system disables the app's widgets. (The widgets are grayed out, and the device user cannot interact with them.) The system re-enables the widgets the next time the user launches the app.

You can call the new ApplicationStartInfo.wasForceStopped() method to confirm whether the app was put into the stopped state.

支持 16 KB 页面大小

Historically, Android has only supported 4 KB memory page sizes, which has optimized system memory performance for the average amount of total memory that Android devices have typically had. Beginning with Android 15, Android supports devices that are configured to use a page size of 16 KB (16 KB devices). If your app uses any NDK libraries, either directly or indirectly through an SDK, then you will need to rebuild your app for it to work on these 16 KB devices.

Devices with larger page sizes can have improved performance for memory-intensive workloads. As device manufacturers continue to build devices with larger amounts of physical memory (RAM), many of these devices will adopt 16 KB (and eventually greater) page sizes to optimize the device's performance. Adding support for 16 KB page size devices enables your app to run on these devices and helps your app benefit from the associated performance improvements. We plan to make 16 KB page compatibility required for app uploads to the Google Play store next year.

As device manufacturers continue to build devices with larger amounts of physical memory (RAM), many of these devices will likely be configured with 16 KB (and eventually greater) page sizes to optimize the device's performance. Adding support for 16 KB devices enables your app to run on these devices and helps your app benefit from the associated performance improvements.

To help you add support for your app, we've provided guidance on how to check if your app is impacted, how to rebuild your app (if applicable), and how to test your app in a 16 KB environment using emulators (including Android 15 system images for the Android Emulator).

Benefits and performance gains

配置为 16 KB 页面的设备平均使用的内存会略多，但系统和应用性能也会有所提升：

• 在系统面临内存压力时缩短应用启动时间：平均降低了 3.16%，对于我们测试过的一些应用而言，改进幅度更显著（提升幅度高达 30%）
• 降低应用启动时的功耗：平均降低 4.56%
• 相机启动速度更快：平均热启动速度加快 4.48%，冷启动速度平均加快 6.60%
• 缩短了系统启动时间：平均缩短了 1.5%（约 0.8 秒）

这些改进基于我们的初始测试，实际设备上的结果可能会有所不同。在继续测试的过程中，我们会进一步分析应用的潜在益处。

Check if your app is impacted

If your app uses any native code, then you should rebuild your app with support for 16 KB devices. If you are unsure if your app uses native code, you can use the APK Analyzer to identify whether any native code is present.

If your app only uses code written in the Java programming language or in Kotlin, including all libraries or SDKs, then your app already supports 16 KB devices. Nevertheless, we recommend that you test your app in a 16 KB environment to verify that there are no unexpected regressions in app behavior.

让部分应用支持私密空间所需的更改

Private space is a new feature in Android 15 that lets users create a separate space on their device where they can keep sensitive apps away from prying eyes, under an additional layer of authentication. Because apps in the private space have restricted visibility, some types of apps need to take additional steps to be able to see and interact with apps in a user's private space.

Caution: There is a known issue with private space in Beta 2 that affects app icons on the Home screen. A fix for this issue is included in the Beta 2.2 release.

All apps

Because apps in the private space are kept in a separate user profile, similar to work profiles, apps shouldn't assume that any installed copies of their app that aren't in the main profile are in the work profile. If your app has logic related to work profile apps that make this assumption, you'll need to adjust this logic.

Launcher apps

If you develop a launcher app, you must do the following before apps in the private space will be visible:

1. Your app must be assigned as the default launcher app for the device—that is, possessing the ROLE_HOME role.
2. Your app must declare the ACCESS_HIDDEN_PROFILES normal permission in your app's manifest file.

Launcher apps that declare the ACCESS_HIDDEN_PROFILES permission must handle the following private space use cases:

1. Your app must have a separate launcher container for apps installed in the private space. Use the getLauncherUserInfo() method to determine which type of user profile is being handled.
2. The user must be able to hide and show the private space container.
3. The user must be able to lock and unlock the private space container. Use the requestQuietModeEnabled() method to lock (by passing true) or unlock (by passing false) the private space.

4. While locked, no apps in the private space container should be visible or discoverable through mechanisms such as search. Your app should register a receiver for the ACTION_PROFILE_AVAILABLE and ACTION_PROFILE_UNAVAILABLE broadcasts and update the UI in your app when the locked or unlocked state of the private space container changes. Both of these broadcasts include EXTRA_USER, which your app can use to refer to the private profile user.

   You can also use the isQuietModeEnabled() method to check whether the private space profile is locked or not.

App store apps

The private space includes an "Install Apps" button that launches an implicit intent to install apps into the user's private space. In order for your app to receive this implicit intent, declare an <intent-filter> in your app's manifest file with a <category> of CATEGORY_APP_MARKET.

移除了基于 PNG 的表情符号字体

The legacy, PNG-based emoji font file (NotoColorEmojiLegacy.ttf) has been removed, leaving just the vector-based file. Beginning with Android 13 (API level 33), the emoji font file used by the system emoji renderer changed from a PNG-based file to a vector based file. The system retained the legacy font file in Android 13 and 14 for compatibility reasons, so that apps with their own font renderers could continue to use the legacy font file until they were able to upgrade.

You can choose to adapt your app in a number of ways:

• Use platform APIs for text rendering. You can render text to a bitmap-backed Canvas and use that to get a raw image if necessary.
• Add COLRv1 font support to your app. The FreeType open source library supports COLRv1 in version 2.13.0 and higher.
• As a last resort, you can bundle the legacy emoji font file (NotoColorEmoji.ttf) into your APK, although in that case your app will be missing the latest emoji updates. For more information, see the Noto Emoji GitHub project page.

将最低目标 SDK 版本从 23 提高到了 24

Android 15 builds on the the changes that were made in Android 14 and extends this security further. In Android 15, apps with a targetSdkVersion lower than 24 can't be installed. Requiring apps to meet modern API levels helps to ensure better security and privacy.

Malware often targets lower API levels in order to bypass security and privacy protections that have been introduced in higher Android versions. For example, some malware apps use a targetSdkVersion of 22 to avoid being subjected to the runtime permission model introduced in 2015 by Android 6.0 Marshmallow (API level 23). This Android 15 change makes it harder for malware to avoid security and privacy improvements. Attempting to install an app targeting a lower API level results in an installation failure, with a message like the following one appearing in Logcat:

INSTALL_FAILED_DEPRECATED_SDK_VERSION: App package must target at least SDK version 24, but found 7

On devices upgrading to Android 15, any apps with a targetSdkVersion lower than 24 remain installed.

If you need to test an app targeting an older API level, use the following ADB command:

adb install --bypass-low-target-sdk-block FILENAME.apk

摄像头和媒体

Android 15 针对所有用户的相机和媒体行为做出了以下变更 。

现在，当达到资源限制时，直接和分流音频播放会使之前打开的直接或分流音轨失效

Before Android 15, if an app requested direct or offload audio playback while another app was playing audio and the resource limits were reached, the app would fail to open a new AudioTrack.

Beginning with Android 15, when an app requests direct or offload playback and the resource limits are reached, the system invalidates any currently open AudioTrack objects which prevent fulfilling the new track request.

(Direct and offload audio tracks are typically opened for playback of compressed audio formats. Common use-cases for playing direct audio include streaming encoded audio over HDMI to a TV. Offload tracks are typically used to play compressed audio on a mobile device with hardware DSP acceleration.)

用户体验和系统界面

Android 15 包含一些旨在打造更一致、更完善的 直观的用户体验。

已为已选择启用预测性返回动画功能启用

Beginning in Android 15, the developer option for predictive back animations has been removed. System animations such as back-to-home, cross-task, and cross-activity now appear for apps that have opted in to the predictive back gesture either entirely or at an activity level. If your app is affected, take the following actions:

• Ensure that your app has been properly migrated to use the predictive back gesture.
• Ensure that your fragment transitions work with predictive back navigation.
• Migrate away from animation and framework transitions and use animator and androidx transitions instead.
• Migrate away from back stacks that FragmentManager doesn't know about. Use back stacks managed by FragmentManager or by the Navigation component instead.

用户强行停止应用时停用的微件

If a user force-stops an app on a device running Android 15, the system temporarily disables all the app's widgets. The widgets are grayed out, and the user cannot interact with them. This is because beginning with Android 15, the system cancels all an app's pending intents when the app is force-stopped.

The system re-enables those widgets the next time the user launches the app.

For more information, see Changes to package stopped state.

废弃

随着每个版本的发布，特定的 Android API 可能会过时或需要 进行了重构，以提供更好的开发者体验或支持新平台 capabilities.在这些情况下，我们正式弃用已过时的 API，并 引导开发者改用替代 API。

弃用意味着我们已结束对这些 API 的正式支持，但它们 也可供开发者使用要详细了解值得关注的重要内容 请参阅弃用页面。