行为变更：所有应用

Android 15 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 15 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 15 为目标平台的应用的行为变更列表。

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've updated 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

Android 过去仅支持 4 KB 内存页面大小， 优化了系统内存性能，以针对 Android 设备通常具备的功能。从 Android 15 开始，AOSP 支持 配置为使用 16 KB (16 KB) 页面大小的设备 设备）。如果您的应用使用任何 NDK 库，请直接使用 或者通过 SDK 间接创建，那么，您需要重新构建自己的应用 支持这些 16KB 设备。

随着设备制造商不断打造出 物理内存 (RAM)，许多此类设备都会采用 16KB（以及 页面大小以优化设备的性能。正在添加 支持 16 KB 页面大小的设备，可使您的应用在这些设备上运行 并有助于您的应用从相关的广告效果中获益 改进。如果不重新编译，应用可能无法在 16KB 设备上运行 在未来的 Android 版本中正式推出。

为帮助您为应用添加支持，我们提供了有关如何检查 如果您的应用受到影响 重新构建您的应用（如果适用），以及如何在 Google Play 中 使用模拟器（包括 Android 15）的 16 KB 环境 系统映像）。

优势和性能提升

配置为使用 16 KB 页面大小的设备平均会使用略多一些的内存，但系统和应用的性能也会得到各种提升：

• 缩短了系统内存压力时的应用启动时间：平均降低了 3.16%；对于我们测试的某些应用而言，改进幅度更大（最高可达 30%）
• 应用启动期间的功耗降低：平均降低了 4.56%
• 相机启动更快：热启动速度平均提高了 4.48%，冷启动速度平均提高了 6.60%
• 缩短了系统启动时间：平均缩短了 8%（约 950 毫秒）

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。随着测试的继续进行，我们将进一步分析应用的潜在收益。

检查您的应用是否受到影响

如果您的应用使用了任何原生代码，则应重新构建应用以支持 16 KB 设备。如果您不确定自己的应用是否使用了原生代码，可以使用 APK 分析器确定是否存在任何原生代码，然后检查您找到的任何共享库的 ELF 段对齐情况。

如果您的应用仅使用以 Java 或 Kotlin 编程语言编写的代码（包括所有库或 SDK），则该应用已经支持 16 KB 设备。不过，我们建议您在 16 KB 环境中测试应用，以验证应用行为是否没有意外回归。

某些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.

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.

Medical apps

When a user locks the private space, all apps in the private space are stopped, and those apps can't perform foreground or background activities, including showing notifications. This behavior might critically impact the use and function of medical apps installed in the private space.

The private space setup experience warns users that the private space is not suitable for apps that need to perform critical foreground or background activities, such as showing notifications from medical apps. However, apps can't determine whether or not they're being used in the private space, so they can't show a warning to the user for this case.

For these reasons, if you develop a medical app, review how this feature might impact your app and take appropriate actions—such as informing your users not to install your app in the private space—to avoid disrupting critical app capabilities.

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.

To check if your app is affected, search your app's code for references to the NotoColorEmojiLegacy.ttf file.

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 基于 在 Android 14 中进行的更改，并扩展了 安全性。在 Android 15 中， 无法安装低于 24 的 targetSdkVersion。 要求应用符合现代 API 级别有助于确保更好的安全性和 保护隐私。

恶意软件通常会以较低的 API 级别为目标平台，以绕过安全和隐私 更高的 Android 版本中引入的保护机制。例如，有些恶意软件应用使用 targetSdkVersion 22，以避免受到 Android 6.0 Marshmallow（API 级别 23）在 2015 年引入的运行时权限模型的约束。这项 Android 15 变更使恶意软件更难以规避安全和隐私权方面的改进限制。尝试安装以较低 API 级别为目标平台的应用将导致安装失败，并且 Logcat 中会显示如下所示的消息：

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

在升级到 Android 15 的设备上，targetSdkVersion 级别较低的任何应用 安装在 Google Play 上

如果您需要测试以旧版 API 级别为目标平台的应用，请使用以下 ADB 命令：

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

安全和隐私设置

Android 15 引入了强大的措施来防范动态密码 (OTP) 欺诈并保护用户的敏感内容，重点是增强通知监听器服务和屏幕共享保护措施。主要增强功能包括从可供不可信应用访问的通知中隐去 OTP、在屏幕共享期间隐藏通知，以及在发布 OTP 时保护应用 activity。这些变更旨在保护用户的敏感内容，使其免受未经授权的操作者的侵害。

开发者需要注意以下事项，以确保其应用与 Android 15 中的变更兼容：

动态密码隐去

Android 会阻止实现 NotificationListenerService 的不受信任应用读取已检测到 OTP 的通知中的未隐去的内容。配套设备管理器关联等受信任应用不受这些限制。

屏幕共享保护

• 在屏幕共享会话期间，系统会隐藏通知内容，以保护用户的隐私。如果应用实现了 setPublicVersion()，Android 会显示通知的公开版本，该版本在不安全情境中用作替换通知。否则，系统会隐去通知内容，不提供任何其他背景信息。
• 系统会向远程观看者隐藏密码输入等敏感内容，以防止泄露用户的敏感信息。
• 如果在屏幕共享期间检测到动态密码，系统会隐藏在该时间段内发布通知的应用的活动。应用内容在启动时会向远程查看器隐藏。
• 除了 Android 自动识别敏感字段之外，开发者还可以使用 setContentSensitivity 手动将应用的部分标记为敏感，在屏幕共享期间，这些敏感字段会对远程观看者隐藏。
• 开发者可以选择切换开发者选项下的停用屏幕共享防护选项，以便出于演示或测试目的豁免屏幕共享防护。默认的系统屏幕录制工具不受这些更改的影响，因为录制内容会保留在设备上。

摄像头和媒体

Android 15 对所有应用的相机和媒体行为做出了以下更改。

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

在 Android 15 之前，如果某个应用在另一个应用正在播放音频时请求直接播放或分流音频播放，并且已达到资源限制，此应用将无法打开新的 AudioTrack。

从 Android 15 开始，当应用请求直接或分流播放并且达到资源限制时，系统会使当前打开的所有 AudioTrack 对象失效，从而阻止执行新的轨道请求。

（直接和分流音轨通常会打开，以播放压缩的音频格式。播放直接音频的常见用例包括通过 HDMI 将编码音频流式传输到电视。分流轨道通常用于在具有硬件 DSP 加速的移动设备上播放压缩音频。）

用户体验和系统界面

Android 15 进行了一些更改，旨在打造更一致、更直观的用户体验。

为选择启用预测性返回手势的应用启用预测性返回动画

从 Android 15 开始，移除了预测性返回动画的开发者选项。现在，对于已完全或在 activity 级别选择启用预测性返回手势的应用，系统现在会显示“返回主屏幕”“跨任务”和“跨 activity”等系统动画。如果您的应用受到影响，请执行以下操作：

• 确保您的应用已正确迁移，以使用预测性返回手势。
• 确保您的 fragment 转换支持预测性返回导航。
• 停止使用动画和框架转换，并改用 Animator 和 AndroidX 转换。
• 从 FragmentManager 不知道的返回堆栈中迁出。请改用由 FragmentManager 或 Navigation 组件管理的返回堆栈。

当用户强制停止应用时，微件被停用

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.

媒体投影状态栏条状标签会提醒用户正在共享屏幕、投放和录制

Preview: This change is included in Android 15 QPR1, which is in beta.

Screen projection exploits expose private user data such as financial information because users don't realize their device screen is being shared. Android has until now shown screen cast and screen record icons on the status bar, but the icons are small and often overlooked. Also, stopping screen sharing or recording is cumbersome because controls are in Quick Settings.

Android 15 introduces a new status bar chip that is large and prominent, which should alert users to any in-progress screen projection. Users can tap the chip to stop their screen from being shared, cast, or recorded.

To provide an intuitive user experience, screen projection now automatically stops when the device screen is locked.

Benefits and performance gains

The new media projection status bar chip enhances the user experience as follows:

• Alerts users to in-progress screen sharing, casting, or recording
• Enable users to terminate screen projection by tapping the chip

Automatic suspension of screen projection when the device screen is locked ensures user privacy.

Check if your app is impacted

By default, your app includes the new status bar chip and automatically suspends screen projection when the lock screen activates. Test your app by implementing the onStop() method of the MediaProjection.Callback. Verify that your app responds appropriately when the screen projection stops as a result of the user tapping the status bar chip or when the lock screen activates.

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重构，以提供更好的开发者体验或支持新的平台功能。在这些情况下，我们会正式废弃过时的 API，并引导开发者改用替代 API。

废弃意味着我们已结束对这些 API 的正式支持，但它们将继续可供开发者使用。如需详细了解此 Android 版本中的重要弃用情况，请参阅“弃用”页面。