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。

前台服务的变更

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

Data sync foreground service timeout behavior

Android 15 针对以目标平台为目标平台的应用为 dataSync 引入了新的超时行为 Android 15 或更高版本。这一行为也适用于新的 mediaProcessing 前台服务类型。

系统允许应用的 dataSync 服务总共运行 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 中引入） 15）。此时，服务有几秒钟的时间来调用 Service.stopSelf().调用 Service.onTimeout() 时， 服务不再被视为前台服务。如果该服务没有 调用 Service.stopSelf() 时，系统会抛出内部异常。通过 Logcat 中会记录以下异常：

Fatal Exception: android.app.RemoteServiceException: "A foreground service of
type dataSync did not stop within its timeout: [component name]"

为避免这种行为变更出现问题，您可以执行下列一项或多项操作 以下：

  1. 让您的服务实现新的 Service.onTimeout(int, int) 方法。 当您的应用收到回调时，请务必在stopSelf() 几秒。（如果您不立即停止应用，则系统会生成 失败。）
  2. 确保应用的 dataSync 服务运行的总时间不超过 在任何 24 小时内为 6 小时（除非用户与应用互动； 重置计时器）。
  3. 仅在用户执行直接操作后启动 dataSync 项前台服务 互动；由于服务启动时您的应用位于前台 您的服务在应用转入后台后的完整运行 6 小时。
  4. 请不要使用 dataSync 前台服务，而应使用 替代 API。

如果您的应用的 dataSync 前台服务在过去 6 小时内运行过 24，除非用户dataSync 已将您的应用调到前台（这会重置计时器）。如果您尝试 启动另一个 dataSync 前台服务时，系统会抛出 ForegroundServiceStartNotAllowedException 并显示类似“前台服务的时限已用尽”的错误消息 type dataSync”。

测试

如需测试应用的行为，您可以启用数据同步超时（即使应用也是如此） 未以 Android 15 为目标平台（只要应用在 Android 15 上运行即可） 设备）。如需启用超时功能，请运行以下 adb 命令：

adb shell am compat enable FGS_INTRODUCE_TIME_LIMITS your-package-name

您还可以调整超时期限，以便更轻松地测试 在达到该限制时，应用的行为。要设置新的超时期限，请运行 以下 adb 命令：

adb shell device_config put activity_manager data_sync_fgs_timeout_duration duration-in-milliseconds

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(), the system throws an internal exception. The exception is logged in Logcat with the following message:

Fatal Exception: android.app.RemoteServiceException: "A foreground service of
type mediaProcessing did not stop within its timeout: [component name]"

To avoid having the exception, 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.

Testing

To test your app's behavior, you can enable media processing timeouts even if your app is not targeting Android 15 (as long as the app is running on an Android 15 device). To enable timeouts, run the following adb command:

adb shell am compat enable FGS_INTRODUCE_TIME_LIMITS your-package-name

You can also adjust the timeout period, to make it easier to test how your app behaves when the limit is reached. To set a new timeout period, run the following adb command:

adb shell device_config put activity_manager media_processing_fgs_timeout_duration duration-in-milliseconds

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.

Testing

To test your app's behavior, you can enable these new restrictions even if your app is not targeting Android 15 (as long as the app is running on an Android 15 device). Run the following adb command:

adb shell am compat enable FGS_BOOT_COMPLETED_RESTRICTIONS your-package-name

To send a BOOT_COMPLETED broadcast without restarting the device, run the following adb command:

adb shell am broadcast -a android.intent.action.BOOT_COMPLETED your-package-name

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

以前，如果应用拥有 SYSTEM_ALERT_WINDOW 权限，那么即使该应用当前在后台运行，它也可以启动前台服务（如不受后台启动限制的豁免中所述）。

如果应用以 Android 15 为目标平台，此豁免范围现在会更严格。该应用现在需要具有 SYSTEM_ALERT_WINDOW 权限，并且还具有可见的叠加窗口。也就是说，在您启动前台服务之前，应用需要先启动 TYPE_APPLICATION_OVERLAY 窗口，并且该窗口必须处于可见状态。

如果您的应用尝试在不满足这些新要求的情况下从后台启动前台服务（并且没有其他某些豁免），系统会抛出 ForegroundServiceStartNotAllowedException。

如果您的应用声明 SYSTEM_ALERT_WINDOW 权限并从后台启动前台服务，则可能会受到此项变更的影响。如果您的应用收到 ForegroundServiceStartNotAllowedException，请检查应用的操作顺序，并确保应用在尝试从后台启动前台服务之前已具备有效的叠加窗口。您可以通过调用 View.getWindowVisibility() 检查叠加层窗口当前是否可见，也可以替换 View.onWindowVisibilityChanged()，以便在可见性发生变化时收到通知。

更改了应用何时可以修改勿扰模式的全局状态

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 API 变更

Android 15 将继续更新 Android 的核心库， 最新 OpenJDK LTS 版本中的功能。

其中一些变更可能会影响应用定位的应用兼容性 Android 15（API 级别 35）：

  • 字符串格式设置 API 变更：验证参数索引、标志、 现在，使用 String.format() 和 Formatter.format() API：

    例如，当参数索引为 0 时，会抛出以下异常 （格式字符串中的 %0）：

    IllegalFormatArgumentIndexException: Illegal format argument index = 0

    在这种情况下，可以使用参数索引为 1 (%1 ）。

  • 对 Arrays.asList(...).toArray() 组件类型的更改：使用 Arrays.asList(...).toArray()，则所得数组的组件类型为 现在是 Object，而不是底层数组元素的类型。因此， 以下代码会抛出 ClassCastException：

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

    在本例中，在结果中将 String 保留为组件类型 数组，您可以改用 Collection.toArray(Object[])：

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

  • 语言代码处理方式变更：使用 Locale API 时， 不再转换希伯来语、意第绪语和印度尼西亚语的语言代码 对应的过时形式（希伯来语：iw、意第绪语：ji 和印度尼西亚语：in）。 在为其中某个语言区域指定语言代码时，请使用代码 改为 ISO 639-1（希伯来语：he，意第绪语：yi，印度尼西亚语：id）。

  • 对随机整数序列的更改： https://bugs.openjdk.org/browse/JDK-8301574，下面 Random.ints() 方法现在返回的数值序列与 Random.nextInt() 方法的用途如下：

    一般来说，此变更不会导致应用中断行为，但您的 代码不应期望 Random.ints() 方法生成的序列 匹配Random.nextInt()。

新的 SequencedCollection API 可能会影响应用的兼容性 当您在应用的 build 配置中更新 compileSdk 以使用 Android 15（API 级别 35）：

  • 与 MutableList.removeFirst() 和 kotlin-stdlib 中的 MutableList.removeLast() 扩展函数

    Java 中的 List 类型会映射到 Kotlin 中的 MutableList 类型。 由于使用 List.removeFirst() 和 List.removeLast() API 已在 Android 15（API 级别 35）中引入，Kotlin 编译器 将函数调用（例如 list.removeFirst()）静态解析为 新的 List API，而不是对 API 中的扩展函数 kotlin-stdlib。

    重新编译应用时，如果 compileSdk 设为 35，并且 minSdk 设为 34 或更低版本，那么应用会在 Android 14 及更低版本（运行时）上运行 错误：

    java.lang.NoSuchMethodError: No virtual method
removeFirst()Ljava/lang/Object; in class Ljava/util/ArrayList;

    Android Gradle 插件中的现有 NewApi lint 选项可以捕获这些 新的 API 用法。

    ./gradlew lint

MainActivity.kt:41: Error: Call requires API level 35 (current min is 34): java.util.List#removeFirst [NewApi]
      list.removeFirst()

    如需修复运行时异常和 lint 错误，removeFirst() 和 removeLast() 函数调用可替换为 removeAt(0)， removeAt(list.lastIndex)（在 Kotlin 中分别对应）。如果您使用的是 Android Studio Ladybug |2024.1.3 或更高版本，也提供快速修复 处理这些错误的选项

    如果 lint 选项已停用，请考虑移除 @SuppressLint("NewApi") 和 lintOptions { disable 'NewApi' }。

  • 与 Java 中的其他方法冲突

    向现有类型中添加了新方法，例如， List 和 Deque。这些新方法 其他接口中具有相同名称和参数类型的方法 和类。如果与 不兼容，javac 编译器会输出构建时错误。例如：

    错误 1 示例：

    javac MyList.java

MyList.java:135: error: removeLast() in MyList cannot implement removeLast() in List
  public void removeLast() {
              ^
  return type void is not compatible with Object
  where E is a type-variable:
    E extends Object declared in interface List

    错误 2 示例：

    javac MyList.java

MyList.java:7: error: types Deque<Object> and List<Object> are incompatible;
public class MyList implements  List<Object>, Deque<Object> {
  both define reversed(), but with unrelated return types
1 error

    错误 3 示例：

    javac MyList.java

MyList.java:43: error: types List<E#1> and MyInterface<E#2> are incompatible;
public static class MyList implements List<Object>, MyInterface<Object> {
  class MyList inherits unrelated defaults for getFirst() from types List and MyInterface
  where E#1,E#2 are type-variables:
    E#1 extends Object declared in interface List
    E#2 extends Object declared in interface MyInterface
1 error

    要修复这些构建错误，实现这些接口的类应 使用兼容的返回值类型替换该方法。例如：

    @Override
public Object getFirst() {
    return List.super.getLast();
}

安全

Android 15 包含一些有助于提升系统安全性的变更，以帮助保护应用和用户免受恶意应用的侵害。

限制后台 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.
  • Pending intents: The creator of the pending intent is treated as the sender of the enclosing intent, not the sender of the pending intent

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 包含一些旨在打造更一致、更直观的用户体验的变更。

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。

Edge-to-edge enforcement

在搭载 Android 15 的设备上，应用会默认采用全屏 以 Android 15（API 级别 35）为目标平台。

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一款以 Android 14 为目标平台且在 Android 设备上未处于无边框的应用 Android 15 设备。


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一款以 Android 15（API 级别 35）为目标平台且采用无边框的应用 在 Android 15 设备上。此应用主要使用 Material 3 Compose 组件 自动应用边衬区此屏幕不会受到 Android 15 全屏强制执行。

这是一项可能会对应用的界面产生负面影响的破坏性更改。通过 更改会影响以下界面区域：

  • 手势手柄导航栏 <ph type="x-smartling-placeholder">
      </ph>
    • 默认透明。
    • 底部偏移量已停用，因此内容绘制在系统导航栏后面 栏。
    • setNavigationBarColor和R.attr#navigationBarColor 已弃用，不会影响手势导航。
    • setNavigationBarContrastEnforced和 R.attr#navigationBarContrastEnforced不会对 手势导航。
  • “三按钮”导航 <ph type="x-smartling-placeholder">
      </ph>
    • 默认不透明度设为 80%，颜色可能与窗口一致 背景。
    • 底部偏移值已停用，因此内容绘制在系统导航栏后面 除非应用了边衬区。
    • setNavigationBarColor和R.attr#navigationBarColor 默认设置为与窗口背景匹配。窗口背景 必须是颜色可绘制对象，才能应用此默认值。此 API 是 但会继续影响“三按钮”导航。
    • setNavigationBarContrastEnforced和 R.attr#navigationBarContrastEnforced 默认为 true，这会添加一个 “三按钮”导航模式显示 80% 不透明的背景。
  • 状态栏 <ph type="x-smartling-placeholder">
      </ph>
    • 默认透明。
    • 顶部偏移量已停用，因此除非 边衬区。
    • setStatusBarColor和R.attr#statusBarColor 已废弃，对 Android 15 没有任何影响。
    • setStatusBarContrastEnforced和 R.attr#statusBarContrastEnforced 已弃用，但仍具有 对 Android 15 的影响。
  • 刘海屏 <ph type="x-smartling-placeholder">
      </ph>
    • layoutInDisplayCutoutMode 的非浮动窗口必须是 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS.SHORT_EDGES、NEVER和 系统会将 DEFAULT 解读为 ALWAYS，这样用户就不会看到黑色图标 长条形尺寸，显示为无边框。

以下示例展示了定位前和定位后的应用 Android 15（API 级别 35）以及应用边衬区之前和之后。

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一款以 Android 14 为目标平台且在 Android 设备上未处于无边框的应用 Android 15 设备。
一款以 Android 15（API 级别 35）为目标平台且采用无边框的应用 在 Android 15 设备上。不过，许多元素 栏、“三按钮”导航栏或刘海屏（由于 Android 15） 全屏强制措施。隐藏界面包含 Material 2 顶部应用栏、悬浮操作按钮和列表项。
如果应用以 Android 15（API 级别 35）为目标平台， Android 15 设备并应用边衬区，这样界面就不会 已隐藏。
检查应用是否已采用全屏的检查步骤

如果您的应用已经采用无边框且应用了边衬区， 基本未受影响，但下列情况除外。但即使您认为 您不会受到影响，但我们建议您测试自己的应用。

  • 您的非浮动窗口（例如 Activity）使用 SHORT_EDGES、NEVER 或 DEFAULT，而不是 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS。如果您的应用在启动时崩溃 可能是启动画面所致您可以升级核心 初始屏幕依赖项更改为 1.2.0-alpha01 或更高版本，或者设置 window.attributes.layoutInDisplayCutoutMode = WindowManager.LayoutInDisplayCutoutMode.always。
  • 可能会有流量较低的屏幕显示被遮挡的界面。验证这些 访问较少的屏幕也不会显示被遮挡的界面。流量较低的屏幕包括： <ph type="x-smartling-placeholder">
      </ph>
    • 初始配置或登录屏幕
    • “设置”页面
如何检查应用尚未实现无边框

如果您的应用还没有全面屏，那么您很可能会受到影响。在 除了针对已经采用无边框的应用的情况之外， 请考虑以下事项：

  • 如果您的应用使用 Material 3 组件 ( androidx.compose.material3)，例如 TopAppBar， BottomAppBar 和 NavigationBar，那么这些组件可能不 会受到影响，因为它们会自动处理边衬区。
  • 如果您的应用使用 Material 2 组件 ( androidx.compose.material），那么这些组件 不会自动处理边衬区。不过，您可以使用边衬区 并手动应用这些设置在 androidx.compose.material 1.6.0 中 然后使用 windowInsets 参数手动应用边衬区 BottomAppBar、TopAppBar、 BottomNavigation 和 NavigationRail。 同样，对以下内容使用 contentWindowInsets 形参： Scaffold.
  • 如果您的应用使用视图和 Material 组件 (com.google.android.material)，大多数基于 View 的 Material 如 BottomNavigationView、BottomAppBar、 NavigationRailView 或 NavigationView，处理边衬区，不需要 额外工作。但是，您需要将 android:fitsSystemWindows="true" 如果使用 AppBarLayout，则会发生此错误。
  • 对于自定义可组合项，请手动将边衬区作为内边距应用。如果您的 内容位于 Scaffold 内，因此您可以使用 Scaffold 来使用边衬区 内边距值。否则，使用 WindowInsets.
  • 如果您的应用使用的是视图和 BottomSheet、SideSheet 或自定义 使用 ViewCompat.setOnApplyWindowInsetsListener。对于 RecyclerView，使用此监听器应用内边距，同时添加 clipToPadding="false".
检查应用是否必须提供自定义后台保护的注意事项

如果您的应用必须为“三按钮”导航或 状态栏，则应用应将可组合项或视图放在系统栏后面 使用 WindowInsets.Type#tappableElement() 获取三按钮 导航栏高度或 WindowInsets.Type#statusBars。

其他无边框资源

请参阅无边框视图和无边框 Compose 了解应用边衬区的其他注意事项。

已弃用的 API

以下 API 现已弃用：

Stable configuration

If your app targets Android 15 (API level 35) 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:

EnglishTextHeight 属性默认为 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

在以前的 Android 版本中，一些采用复杂形状的草体字体或语言可能会在上一个或下一个字符区域中绘制字母。在某些情况下，此类字母会在开始或结束位置被截断。从 Android 15 开始，TextView 会分配宽度来为此类字母绘制足够的空间，并允许应用请求左侧添加额外的内边距以防止被裁剪。

由于此变更会影响 TextView 确定宽度的方式，因此如果应用以 Android 15 或更高版本为目标平台，TextView 会默认分配更多宽度。您可以通过对 TextView 调用 setUseBoundsForWidth API 来启用或停用此行为。

由于添加左侧内边距可能会导致现有布局未对齐，因此默认情况下，系统不会添加内边距，即使对于以 Android 15 或更高版本为目标平台的应用也是如此。不过，您可以通过调用 setShiftDrawingOffsetForStartOverhang 添加额外的内边距以防止裁剪。

以下示例展示了这些更改如何改进某些字体和语言的文本布局。

以手写体字体显示的英语文本的标准布局。部分字母会被截断。相应的 XML 如下：

<TextView
    android:fontFamily="cursive"
    android:text="java" />
包含额外宽度和内边距的相同英文文本的布局。相应的 XML 如下：

<TextView
    android:fontFamily="cursive"
    android:text="java"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />
泰语文字的标准版式。部分字母被截断。 相应的 XML 如下：

<TextView
    android:text="คอมพิวเตอร์" />
相同泰语文本的布局，但有额外的宽度和内边距。相应的 XML 如下：

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

EditText 的语言区域感知型默认行高

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。

请求音频焦点的限制

Apps that target Android 15 must be the top app or running a 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.

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

更新后的非 SDK 限制

Android 15 includes updated lists of restricted non-SDK interfaces based on collaboration with Android developers and the latest internal testing. Whenever possible, we make sure that public alternatives are available before we restrict non-SDK interfaces.

If your app does not target Android 15, some of these changes might not immediately affect you. However, while it's possible for your app to access some non-SDK interfaces depending on your app's target API level, using any non-SDK method or field always carries a high risk of breaking your app.

If you are unsure if your app uses non-SDK interfaces, you can test your app to find out. If your app relies on non-SDK interfaces, you should begin planning a migration to SDK alternatives. Nevertheless, we understand that some apps have valid use cases for using non-SDK interfaces. If you can't find an alternative to using a non-SDK interface for a feature in your app, you should request a new public API.

To learn more about the changes in this release of Android, see Updates to non-SDK interface restrictions in Android 15. To learn more about non-SDK interfaces generally, see Restrictions on non-SDK interfaces.