行为变更：以 Android 15 或更高版本为目标平台的应用

与以前的版本一样，Android 15 包含一些行为变更，这些变更可能会影响您的应用。以下行为变更仅影响以 Android 15 或更高版本为目标平台的应用。如果您的应用以 Android 15 或更高版本为目标平台，您应该修改自己的应用以适当地支持这些行为（如果适用）。

此外，请务必查看对 Android 15 上运行的所有应用都有影响的行为变更列表（无论应用的 targetSdkVersion 如何）。

核心功能

Android 15 修改或扩展了 Android 系统的各种核心功能。

前台服务变更

We are making the following changes to foreground services with Android 15.

Data sync foreground service timeout behavior

Android 15 对于以 Android 15 或更高版本为目标平台的应用，在 dataSync 中引入了新的超时行为。此行为也适用于新的 mediaProcessing 前台服务类型。

系统允许应用的 dataSync 服务在 24 小时内运行总共 6 小时，之后系统会调用正在运行的服务的 Service.onTimeout(int, int) 方法（在 Android 15 中引入）。此时，服务只有几秒钟的时间来调用 Service.stopSelf()。当调用 Service.onTimeout() 时，该服务不再被视为前台服务。如果服务未调用 Service.stopSelf()，则会发生故障，并显示以下错误消息：“A for 前台服务 (<fgs_type> does not stop in their timeout: <component_name>)”。在 Beta 版 2 中，失败消息显示为 ANR，但在未来的 Beta 版中，此失败消息将抛出自定义异常。

为避免此行为变更出现问题，您可以执行以下一项或多项操作：

  1. 让您的服务实现新的 Service.onTimeout(int, int) 方法。当应用收到回调时，请确保在几秒钟内调用 stopSelf()。（如果您没有立即停止应用，系统会生成故障。）
  2. 确保应用的 dataSync 服务在任何 24 小时内的运行时间总共不超过 6 小时（除非用户与应用互动，请重置计时器）。
  3. 仅因直接用户互动而启动 dataSync 前台服务；由于您的应用在服务启动时正处于前台，因此在它进入后台后，您的服务有整整六个小时的时间。
  4. 请使用替代 API，而不要使用 dataSync 前台服务。

如果应用的 dataSync 前台服务在过去 24 小时内运行了 6 小时，那么除非用户已将您的应用带到前台（这会重置计时器），否则您无法启动其他 dataSync 前台服务。如果您尝试启动另一个 dataSync 前台服务，系统会抛出 ForegroundServiceStartNotAllowedException，并显示“时间限制已用完前台服务类型 dataSync 的时间限制”这样的错误消息。

New media processing foreground service type

Android 15 introduces a new foreground service type, mediaProcessing. This service type is appropriate for operations like transcoding media files. For example, a media app might download an audio file and need to convert it to a different format before playing it. You can use a mediaProcessing foreground service to make sure the conversion continues even while the app is in the background.

The system permits an app's mediaProcessing services to run for a total of 6 hours in a 24-hour period, after which the system calls the running service's Service.onTimeout(int, int) method (introduced in Android 15). At this time, the service has a few seconds to call Service.stopSelf(). If the service does not call Service.stopSelf(), a failure will occur with this error message: "A foreground service of <fgs_type> did not stop within its timeout: <component_name>". In Beta 2, the failure message is shown as an ANR, but in a future Beta release, this failure message will throw a custom exception.

To avoid getting an ANR, you can do one of the following:

  1. Have your service implement the new Service.onTimeout(int, int) method. When your app receives the callback, make sure to call stopSelf() within a few seconds. (If you don't stop the app right away, the system generates a failure.)
  2. Make sure your app's mediaProcessing services don't run for more than a total of 6 hours in any 24-hour period (unless the user interacts with the app, resetting the timer).
  3. Only start mediaProcessing foreground services as a result of direct user interaction; since your app is in the foreground when the service starts, your service has the full six hours after the app goes to the background.
  4. Instead of using a mediaProcessing foreground service, use an alternative API, like WorkManager.

If your app's mediaProcessing foreground services have run for 6 hours in the last 24, you cannot start another mediaProcessing foreground service unless the user has brought your app to the foreground (which resets the timer). If you try to start another mediaProcessing foreground service, the system throws ForegroundServiceStartNotAllowedException with an error message like "Time limit already exhausted for foreground service type mediaProcessing".

For more information about the mediaProcessing service type, see Changes to foreground service types for Android 15: Media processing.

Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services

There are new restrictions on BOOT_COMPLETED broadcast receivers launching foreground services. BOOT_COMPLETED receivers are not allowed to launch the following types of foreground services:

If a BOOT_COMPLETED receiver tries to launch any of those types of foreground services, the system throws ForegroundServiceStartNotAllowedException.

Restrictions on starting foreground services while an app holds the SYSTEM_ALERT_WINDOW permission

Previously, if an app held the SYSTEM_ALERT_WINDOW permission, it could launch a foreground service even if the app was currently in the background (as discussed in exemptions from background start restrictions).

If an app targets Android 15, this exemption is now narrower. The app now needs to have the SYSTEM_ALERT_WINDOW permission and also have a visible overlay window. That is, the app needs to first launch a TYPE_APPLICATION_OVERLAY window and the window needs to be visible before you start a foreground service.

If your app attempts to start a foreground service from the background without meeting these new requirements (and it does not have some other exemption), the system throws ForegroundServiceStartNotAllowedException.

If your app declares the SYSTEM_ALERT_WINDOW permission and launches foreground services from the background, it may be affected by this change. If your app gets a ForegroundServiceStartNotAllowedException, check your app's order of operations and make sure your app already has an active overlay window before it attempts to start a foreground service from the background. You can check if your overlay window is currently visible by calling View.getWindowVisibility(), or you can override View.onWindowVisibilityChanged() to get notified whenever the visibility changes.

对应用何时可以修改“勿扰”模式的全局状态所做的更改

Apps that target Android 15 can no longer change the global state or policy of Do Not Disturb (DND) on a device (either by modifying user settings, or turning off DND mode). Instead, apps must contribute an AutomaticZenRule, which the system combines into a global policy with the existing most-restrictive-policy-wins scheme. Calls to existing APIs that previously affected global state (setInterruptionFilter, setNotificationPolicy) result in the creation or update of an implicit AutomaticZenRule, which is toggled on and off depending on the call-cycle of those API calls.

Note that this change only affects observable behavior if the app is calling setInterruptionFilter(INTERRUPTION_FILTER_ALL) and expects that call to deactivate an AutomaticZenRule that was previously activated by their owners.

OpenJDK 17 变更

Android 15 continues the work of refreshing Android's core libraries to align with the features in the latest OpenJDK LTS releases.

One of these changes can affect app compatibility for apps targeting Android 15:

  • Changes to string formatting APIs: Validation of argument index, flags, width, and precision are now more strict when using the following String.format() and Formatter.format() APIs:

    For example, the following exception is thrown when an argument index of 0 is used (%0 in the format string):

    IllegalFormatArgumentIndexException: Illegal format argument index = 0

    In this case, the issue can be fixed by using an argument index of 1 (%1 in the format string).

  • Changes to component type of Arrays.asList(...).toArray(): When using Arrays.asList(...).toArray(), the component type of the resulting array is now an Object—not the type of the underlying array's elements. So the following code throws a ClassCastException:

    String[] elements = (String[]) Arrays.asList("one", "two").toArray();

    For this case, to preserve String as the component type in the resulting array, you could use Collection.toArray(Object[]) instead:

    String[] elements = Arrays.asList("two", "one").toArray(new String[0]);

  • Changes to language code handling: When using the Locale API, language codes for Hebrew, Yiddish, and Indonesian are no longer converted to their obsolete forms (Hebrew: iw, Yiddish: ji, and Indonesian: in). When specifying the language code for one of these locales, use the codes from ISO 639-1 instead (Hebrew: he, Yiddish: yi, and Indonesian: id).

  • Changes to random int sequences: Following the changes made in https://bugs.openjdk.org/browse/JDK-8301574, the following Random.ints() methods now return a different sequence of numbers than the Random.nextInt() methods do:

    Generally, this change shouldn't result in app-breaking behavior, but your code shouldn't expect the sequence generated from Random.ints() methods to match Random.nextInt().

安全性

Android 15 包含一些旨在提升系统安全性的变更，有助于保护应用和用户免受恶意应用的侵害。

安全的后台 activity 启动

Android 15 protects users from malicious apps and gives them more control over their devices by adding changes that prevent malicious background apps from bringing other apps to the foreground, elevating their privileges, and abusing user interaction. Background activity launches have been restricted since Android 10 (API level 29).

Block apps that don't match the top UID on the stack from launching activities

Malicious apps can launch another app's activity within the same task, then overlay themselves on top, creating the illusion of being that app. This "task hijacking" attack bypasses current background launch restrictions because it all occurs within the same visible task. To mitigate this risk, Android 15 adds a flag that blocks apps that don't match the top UID on the stack from launching activities. To opt in for all of your app's activities, update the allowCrossUidActivitySwitchFromBelow attribute in your app's AndroidManifest.xml file:

<application android:allowCrossUidActivitySwitchFromBelow="false" >

The new security measures are active if all of the following are true:

  • The app performing the launch targets Android 15.
  • The app on top of the task stack targets Android 15.
  • Any visible activity has opted in to the new protections

If the security measures are enabled, apps might return home, rather than the last visible app, if they finish their own task.

Other changes

In addition to the restriction for UID matching, these other changes are also included:

  • Change PendingIntent creators to block background activity launches by default. This helps prevent apps from accidentally creating a PendingIntent that could be abused by malicious actors.
  • Don't bring an app to the foreground unless the PendingIntent sender allows it. This change aims to prevent malicious apps from abusing the ability to start activities in the background. By default, apps are not allowed to bring the task stack to the foreground unless the creator allows background activity launch privileges or the sender has background activity launch privileges.
  • Control how the top activity of a task stack can finish its task. If the top activity finishes a task, Android will go back to whichever task was last active. Moreover, if a non-top activity finishes its task, Android will go back to the home screen; it won't block the finish of this non-top activity.
  • Prevent launching arbitrary activities from other apps into your own task. This change prevents malicious apps from phishing users by creating activities that appear to be from other apps.
  • Block non-visible windows from being considered for background activity launches. This helps prevent malicious apps from abusing background activity launches to display unwanted or malicious content to users.

更安全的 intent

Android 15 introduces new security measures to make intents safer and more robust. These changes are aimed at preventing potential vulnerabilities and misuse of intents that can be exploited by malicious apps. There are two main improvements to the security of intents in Android 15:

  • Match target intent-filters: Intents that target specific components must accurately match the target's intent-filter specifications. If you send an intent to launch another app's activity, the target intent component needs to align with the receiving activity's declared intent-filters.
  • Intents must have actions: Intents without an action will no longer match any intent-filters. This means that intents used to start activities or services must have a clearly defined action.

Kotlin


fun onCreate() {
    StrictMode.setVmPolicy(VmPolicy.Builder()
        .detectUnsafeIntentLaunch()
        .build()
    )
}

Java


public void onCreate() {
    StrictMode.setVmPolicy(new VmPolicy.Builder()
            .detectUnsafeIntentLaunch()
            .build());
}

用户体验和系统界面

Android 15 包含一些变更，旨在打造更一致、更直观的用户体验。

窗口边衬区更改

Android 15 中有两个与窗口边衬区相关的变更：默认强制执行无边框模式；还存在配置变更，例如系统栏的默认配置。

全面强制执行

如果应用以 Android 15 为目标平台，则在搭载 Android 15 的设备上默认采用无边框应用。

应用以 Android 14 为目标平台且在 Android 15 设备上并非全屏显示的应用。


一个以 Android 15 为目标平台且在 Android 15 设备上实现无边框的应用。此应用主要使用可自动应用边衬区的 Material 3 Compose 组件。此屏幕不会受到 Android 15 无边框强制执行的影响。

这是一项重大变更，可能会对应用的界面产生负面影响。这些更改会影响以下界面区域：

  • 手势手柄导航栏
    • 默认为透明。
    • 底部偏移已停用，因此除非应用边衬区，否则内容会绘制在系统导航栏后面。
    • setNavigationBarColor 和 R.attr#navigationBarColor 已废弃，不会影响手势导航。
    • setNavigationBarContrastEnforced 和 R.attr#navigationBarContrastEnforced 仍然对手势导航没有影响。
  • “三按钮”导航
    • 不透明度默认设置为 80%，颜色可能与窗口背景匹配。
    • 已停用底部偏移，因此内容绘制在系统导航栏后面，除非应用边衬区。
    • 默认情况下，setNavigationBarColor 和 R.attr#navigationBarColor 设置为与窗口背景匹配。窗口背景必须是彩色可绘制对象，才能应用此默认设置。此 API 已废弃，但会继续影响“三按钮”导航。
    • setNavigationBarContrastEnforced 和 R.attr#navigationBarContrastEnforced 默认情况下为 true，这会在“三按钮”导航中添加 80% 的不透明背景。
  • 状态栏
    • 默认为透明。
    • 顶部偏移量已停用，因此，除非应用边衬区，否则内容会显示在状态栏后面。
    • setStatusBarColor 和 R.attr#statusBarColor 已废弃，对 Android 15 没有任何影响。
    • setStatusBarContrastEnforced 和 R.attr#statusBarContrastEnforced 已废弃，但在 Android 15 上仍然有效。
  • 刘海屏
    • 非浮动窗口的 layoutInDisplayCutoutMode 必须为 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS。SHORT_EDGES、NEVER 和 DEFAULT 会被解释为 ALWAYS，这样用户就不会看到由刘海屏导致的黑条，而无边框。

以下示例展示了以 Android 15 为目标平台之前和之后以及应用边衬区前后的应用。

应用以 Android 14 为目标平台且在 Android 15 设备上并非全屏显示的应用。
一个以 Android 15 为目标平台且在 Android 15 设备上实现无边框的应用。不过，由于 Android 15 的无边框强制措施，许多元素现在被状态栏、“三按钮”导航栏或刘海屏遮挡。被遮盖的界面包括 Material 2 顶部应用栏、悬浮操作按钮和列表项。
如果应用以 Android 15 为目标平台，则可以在 Android 15 设备上全屏显示，并会应用边衬区来避免界面被遮挡。
检查应用是否已无边框的检查方法

如果您的应用已经无边框并应用了边衬区，则基本上不受影响，下列场景除外。不过，即使您认为自己不受影响，我们也建议您测试自己的应用。

  • 您有一个非浮动窗口，例如，使用 SHORT_EDGES、NEVER 或 DEFAULT（而非 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS）的 Activity。如果您的应用在启动时崩溃，这可能是由于启动画面所致。您可以将核心启动画面依赖项升级到 1.2.0-alpha01 或更高版本，也可以设置 window.attributes.layoutInDisplayCutoutMode = WindowManager.LayoutInDisplayCutoutMode.always。
  • 可能存在流量较低且界面被遮挡的屏幕。验证这些访问较少的屏幕没有被遮挡的界面。流量较低的屏幕包括：
    • 初始配置或登录屏幕
    • “设置”页面
如果您的应用还不是无边框应用的，请检查哪些内容

如果您的应用尚未边缘化，那么您很有可能受到影响。除了已实现无边框应用的场景之外，您还应考虑以下事项：

  • 如果应用在 Compose 中使用 Material 3 组件 (androidx.compose.material3)（例如 TopAppBar、BottomAppBar 和 NavigationBar），这些组件可能不会受到影响，因为它们会自动处理边衬区。
  • 如果应用在 Compose 中使用 Material 2 组件 (androidx.compose.material)，这些组件不会自动处理边衬区。不过，您可以访问边衬区并手动应用边衬区。在 androidx.compose.material 1.6.0 及更高版本中，使用 windowInsets 参数为 BottomAppBar、TopAppBar、BottomNavigation 和 NavigationRail 手动应用边衬区。同样，请为 Scaffold 使用 contentWindowInsets 参数。
  • 如果您的应用使用视图和 Material 组件 (com.google.android.material)，大多数基于视图的 Material 组件（例如 BottomNavigationView、BottomAppBar、NavigationRailView 或 NavigationView）会处理边衬区，无需额外的工作。不过，如果使用 AppBarLayout，则需要添加 android:fitsSystemWindows="true"。
  • 对于自定义可组合项，请手动应用边衬区作为内边距。如果您的内容位于 Scaffold 内，您可以使用 Scaffold 内边距值消耗边衬区。否则，请使用 WindowInsets 之一应用内边距。
  • 如果您的应用使用的是视图和 BottomSheet、SideSheet 或自定义容器，请使用 ViewCompat.setOnApplyWindowInsetsListener 应用内边距。对于 RecyclerView，请使用此监听器应用内边距，并添加 clipToPadding="false"。
检查应用是否必须提供自定义后台保护的事项

如果您的应用必须为“三按钮”导航或状态栏提供自定义后台保护，则应使用 WindowInsets.Type#tappableElement() 获取“三按钮”导航栏高度或 WindowInsets.Type#statusBars，将可组合项或视图放置在系统栏后面。

其他无边框资源

如需了解应用边衬区的其他注意事项，请参阅边缘视图和 Edge to Edge Compose 指南。

已弃用的 API

以下 API 现已废弃：

稳定配置

If your app targets Android 15 or higher, Configuration no longer excludes the system bars. If you use the screen size in the Configuration class for layout calculation, you should replace it with better alternatives like an appropriate ViewGroup, WindowInsets, or WindowMetricsCalculator depending on your need.

Configuration has been available since API 1. It is typically obtained from Activity.onConfigurationChanged. It provides information like window density, orientation, and sizes. One important characteristic about the window sizes returned from Configuration is that it previously excluded the system bars.

The configuration size is typically used for resource selection, such as /res/layout-h500dp, and this is still a valid use case. However, using it for layout calculation has always been discouraged. If you do so, you should move away from it now. You should replace the use of Configuration with something more suitable depending on your use case.

If you use it to calculate the layout, use an appropriate ViewGroup, such as CoordinatorLayout or ConstraintLayout. If you use it to determine the height of the system navbar, use WindowInsets. If you want to know the current size of your app window, use computeCurrentWindowMetrics.

The following list describes the fields affected by this change:

decker TextHeight 属性默认设为 true

For apps targeting Android 15, the elegantTextHeight TextView attribute becomes true by default, replacing the compact font used by default with some scripts that have large vertical metrics with one that is much more readable. The compact font was introduced to prevent breaking layouts; Android 13 (API level 33) prevents many of these breakages by allowing the text layout to stretch the vertical height utilizing the fallbackLineSpacing attribute.

In Android 15, the compact font still remains in the system, so your app can set elegantTextHeight to false to get the same behavior as before, but it is unlikely to be supported in upcoming releases. So, if your app supports the following scripts: Arabic, Lao, Myanmar, Tamil, Gujarati, Kannada, Malayalam, Odia, Telugu or Thai, test your app by setting elegantTextHeight to true.

elegantTextHeight behavior for apps targeting Android 14 (API level 34) and lower.
elegantTextHeight behavior for apps targeting Android 15.

复杂字母形状的 TextView 宽度变化

In previous versions of Android, some cursive fonts or languages that have complex shaping might draw the letters in the previous or next character's area. In some cases, such letters were clipped at the beginning or ending position. Starting in Android 15, a TextView allocates width for drawing enough space for such letters and allows apps to request extra paddings to the left to prevent clipping.

Because this change affects how a TextView decides the width, TextView allocates more width by default if the app targets Android 15 or higher. You can enable or disable this behavior by calling the setUseBoundsForWidth API on TextView.

Because adding left padding might cause a misalignment for existing layouts, the padding is not added by default even for apps that target Android 15 or higher. However, you can add extra padding to preventing clipping by calling setShiftDrawingOffsetForStartOverhang.

The following examples show how these changes can improve text layout for some fonts and languages.

Standard layout for English text in a cursive font. Some of the letters are clipped. Here is the corresponding XML:

<TextView
    android:fontFamily="cursive"
    android:text="java" />
Layout for the same English text with additional width and padding. Here is the corresponding XML:

<TextView
    android:fontFamily="cursive"
    android:text="java"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />
Standard layout for Thai text. Some of the letters are clipped. Here is the corresponding XML:

<TextView
    android:text="คอมพิวเตอร์" />
Layout for the same Thai text with additional width and padding. Here is the corresponding XML:

<TextView
    android:text="คอมพิวเตอร์"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />

EditText 的语言区域感知默认行高

In previous versions of Android, the text layout stretched the height of the text to meet the line height of the font that matched the current locale. For example, if the content was in Japanese, because the line height of the Japanese font is slightly larger than the one of a Latin font, the height of the text became slightly larger. However, despite these differences in line heights, the EditText element was sized uniformly, regardless of the locale being used, as illustrated in the following image:

Three boxes representing EditText elements that can contain text from English (en), Japanese (ja), and Burmese (my). The height of the EditText is the same, even though these languages have different line heights from each other.

For apps targeting Android 15, a minimum line height is now reserved for EditText to match the reference font for the specified Locale, as shown in the following image:

Three boxes representing EditText elements that can contain text from English (en), Japanese (ja), and Burmese (my). The height of the EditText now includes space to accommodate the default line height for these languages' fonts.

If needed, your app can restore the previous behavior by specifying the useLocalePreferredLineHeightForMinimum attribute to false, and your app can set custom minimum vertical metrics using the setMinimumFontMetrics API in Kotlin and Java.

摄像头和媒体

对于以 Android 15 或更高版本为目标平台的应用，Android 15 对相机和媒体行为做出了以下变更。

与请求音频焦点相关的限制

Apps that target Android 15 must be the top app or running an audio-related foreground service in order to request audio focus. If an app attempts to request focus when it does not meet one of these requirements, the call returns AUDIOFOCUS_REQUEST_FAILED.

A foreground service is considered audio-related if its type is mediaPlayback, camera, microphone, or phoneCall.

You can learn more about audio focus at Manage audio focus.

更新后的非 SDK 限制

Android 15 包含更新后的受限非 SDK 接口列表（基于与 Android 开发者之间的协作以及最新的内部测试）。在限制使用非 SDK 接口之前，我们会尽可能确保有可用的公开替代方案。

如果您的应用并非以 Android 15 为目标平台，其中一些变更可能不会立即对您产生影响。不过，虽然您的应用可以访问某些非 SDK 接口（具体取决于应用的目标 API 级别），但使用任何非 SDK 方法或字段始终存在导致应用出问题的显著风险。

如果您不确定自己的应用是否使用了非 SDK 接口，则可以测试该应用进行确认。如果您的应用依赖于非 SDK 接口，则应开始计划迁移到 SDK 替代方案。不过，我们知道某些应用具有使用非 SDK 接口的有效用例。如果您无法为应用中的功能找到无需使用非 SDK 接口的替代方案，则应请求新的公共 API。

如需详细了解此 Android 版本中的变更，请参阅 Android 15 中有关限制非 SDK 接口的更新。如需全面了解有关非 SDK 接口的详细信息，请参阅对非 SDK 接口的限制。