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

软件包 FLAG_STOPPED 状态（用户可以通过长按应用图标并选择“强行停止”来参与 AOSP build）一直是为了让应用保持此状态，直到用户通过直接启动应用或间接与应用互动（通过 Sharesheet 或 widget、选择应用作为动态壁纸等）将应用从此状态明确移除。在 Android 15 中，我们将更新系统的行为，以符合这一预期行为。只能通过用户直接或间接操作将应用从停止状态中移除。

为了支持预期行为，除了现有限制之外，当应用在搭载 Android 15 的设备上进入停止状态时，系统还会取消所有待处理 intent。当用户的操作将应用从停止状态中移除时，系统会向应用传递 ACTION_BOOT_COMPLETED 广播，让用户有机会重新注册任何待处理的 intent。

您可以调用新的 ApplicationStartInfo.wasForceStopped() 方法来确认应用是否已置于停止状态。

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 introduces robust measures to combat one-time passcode (OTP) fraud and to protect the user's sensitive content, focusing on hardening the Notification Listener Service and screenshare protections. Key enhancements include redacting OTPs from notifications accessible to untrusted apps, hiding notifications during screenshare, and securing app activities when OTPs are posted. These changes aim to keep the user's sensitive content safe from unauthorized actors.

Developers need to be aware of the following to ensure their apps are compatible with the changes in Android 15:

OTP Redaction

Android will stop untrusted apps that implement a NotificationListenerService from reading unredacted content from notifications where an OTP has been detected. Trusted apps such as companion device manager associations are exempt from these restrictions.

Screenshare Protection

  • Notification content is hidden during screen sharing sessions to preserve the user's privacy. If the app implements setPublicVersion(), Android shows the public version of the notification which serves as a replacement notification in insecure contexts. Otherwise, the notification content is redacted without any further context.
  • Sensitive content like password input is hidden from remote viewers to prevent revealing the user's sensitive information.
  • Activities from apps that post notifications during screenshare where an OTP has been detected will be hidden. App content is hidden from the remote viewer when launched.
  • Beyond Android's automatic identification of sensitive fields, developers can manually mark parts of their app as sensitive using setContentSensitivity, which is hidden from remote viewers during screenshare.
  • Developers can choose to toggle the Disable screen share protections option under Developer Options to be exempted from the screenshare protections for demo or testing purposes. The default system screen recorder is exempted from these changes, since the recordings remain on-device.

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

如果用户在搭载 Android 15 的设备上强行停止某个应用，系统会暂时停用该应用的所有 widget。这些 widget 会灰显，用户无法与它们互动。这是因为，从 Android 15 开始，当应用被强行停止时，系统会取消应用的所有待处理 intent。

系统会在用户下次启动应用时重新启用这些 widget。

如需了解详情，请参阅对软件包停止状态的更改。

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

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。