行为变更：以 Android 15 或更高版本为目标平台的应用

与之前的版本一样，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
• New media processing foreground service type
• Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services
• Restrictions on starting foreground services while an app holds the SYSTEM_ALERT_WINDOW permission

Data sync foreground service timeout behavior

Android 15 introduces a new timeout behavior to dataSync for apps targeting Android 15 (API level 35) or higher. This behavior also applies to the new mediaProcessing foreground service type.

The system permits an app's dataSync 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(). When Service.onTimeout() is called, the service is no longer considered a foreground service. 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 dataSync did not stop within its timeout: [component name]"

Note: The 6-hour time limit is shared by all of an app's dataSync foreground services. For example, if an app runs a dataSync service for four hours, then starts a different dataSync service, that second service will only be allowed to run for two hours. However, if the user brings the app to the foreground, the timer resets and the app has 6 hours available.

To avoid problems with this behavior change, you can do one or more 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 dataSync 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 dataSync 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 dataSync foreground service, use an alternative API.

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

Testing

To test your app's behavior, you can enable data sync 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 data_sync_fgs_timeout_duration duration-in-milliseconds

New media processing foreground service type

Android 15 引入了一种新的前台服务类型 mediaProcessing。此服务类型适用于转码媒体文件等操作。例如，媒体应用可能会下载音频文件，并需要先将其转换为其他格式，然后才能播放。您可以使用 mediaProcessing 前台服务，确保即使应用在后台运行时转换也会继续。

系统允许应用的 mediaProcessing 服务在 24 小时内总共运行 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 15 中引入）。此时，服务有几秒钟的时间来调用 Service.stopSelf()。如果服务未调用 Service.stopSelf()，系统会抛出内部异常。系统会在 Logcat 中记录此异常，并显示以下消息：

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

注意 ：6 小时的时间限制由应用的所有mediaProcessing前台服务共享。例如，如果应用运行 mediaProcessing 服务四小时，然后启动其他 mediaProcessing 服务，则第二个服务将只能运行两小时。不过，如果用户将应用调到前台，计时器会重置，并且应用将有 6 小时的可用时间。

为避免出现此异常，您可以执行以下任一操作：

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，请务必在几秒钟内调用 stopSelf()。（如果您未立即停止应用，系统会生成失败情况。）
2. 确保应用的 mediaProcessing 服务在任何 24 小时内总运行时间不超过 6 小时（除非用户与应用互动，重置计时器）。
3. 仅在有直接用户互动时启动 mediaProcessing 前台服务；由于服务启动时应用位于前台，因此您的服务在应用进入后台后有完整的 6 小时时间。
4. 请改用 替代 API（例如 WorkManager），而不是使用 mediaProcessing 前台服务。

如果您的应用的 mediaProcessing 前台服务在过去 24 小时内运行了 6 小时，则您无法启动其他 mediaProcessing 前台服务，除非用户将您的应用切换到前台（这会重置计时器）。如果您尝试启动另一个 mediaProcessing 前台服务，系统会抛出 ForegroundServiceStartNotAllowedException，并显示类似于“前台服务类型 mediaProcessing 的时间限制已用尽”的错误消息。

如需详细了解 mediaProcessing 服务类型，请参阅 Android 15 前台服务类型变更：媒体处理。

测试

如需测试应用的行为，您可以启用媒体处理超时，即使您的应用并非以 Android 15 为目标平台也是如此（前提是应用在 Android 15 设备上运行）。如需启用超时，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，以便更轻松地测试应用在达到上限时的行为方式。如需设置新的超时期限，请运行以下 adb 命令：

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:

• dataSync
• camera
• mediaPlayback
• phoneCall
• mediaProjection
• microphone (this restriction has been in place for microphone since Android 14)

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

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.

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). To enable these new restrictions on starting foreground services from the background, run the following adb command:

adb shell am compat enable FGS_SAW_RESTRICTIONS your-package-name

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 (API level 35) and higher 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 continues the work of refreshing Android's core libraries to align with the features in the latest OpenJDK LTS releases.

Some of these changes can affect app compatibility for apps targeting Android 15 (API level 35):

• 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:

  • String.format(String, Object[])
  • String.format(Locale, String, Object[])
  • Formatter.format(String, Object[])
  • Formatter.format(Locale, String, Object[])

  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:

  • Random.ints(long)
  • Random.ints(long, int, int)
  • Random.ints(int, int)
  • Random.ints()

  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().

The new SequencedCollection API can affect your app's compatibility after you update compileSdk in your app's build configuration to use Android 15 (API level 35):

• Collision with MutableList.removeFirst() and MutableList.removeLast() extension functions in kotlin-stdlib

  The List type in Java is mapped to the MutableList type in Kotlin. Because the List.removeFirst() and List.removeLast() APIs have been introduced in Android 15 (API level 35), the Kotlin compiler resolves function calls, for example list.removeFirst(), statically to the new List APIs instead of to the extension functions in kotlin-stdlib.

  If an app is re-compiled with compileSdk set to 35 and minSdk set to 34 or lower, and then the app is run on Android 14 and lower, a runtime error is thrown:

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

  The existing NewApi lint option in Android Gradle Plugin can catch these new API usages.

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

  To fix the runtime exception and lint errors, the removeFirst() and removeLast() function calls can be replaced with removeAt(0) and removeAt(list.lastIndex) respectively in Kotlin. If you're using Android Studio Ladybug | 2024.1.3 or higher, it also provides a quick fix option for these errors.

  Consider removing @SuppressLint("NewApi") and lintOptions { disable 'NewApi' } if the lint option has been disabled.

• Collision with other methods in Java

  New methods have been added into the existing types, for example, List and Deque. These new methods might not be compatible with the methods with the same name and argument types in other interfaces and classes. In the case of a method signature collision with incompatibility, the javac compiler outputs a build-time error. For example:

  Example error 1:

  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
  

  Example error 2:

  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
  

  Example error 3:

  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
  

  To fix these build errors, the class implementing these interfaces should override the method with a compatible return type. For example:

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

安全

Android 15 中包含一些有助于提升系统安全性的变更，可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).

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 引入了新的可选安全措施，以提高 intent 的安全性和稳健性。这些变更旨在防止潜在的漏洞以及恶意应用可能利用的 intent 滥用行为。Android 15 对 intent 的安全性进行了两项主要改进：

• 与目标 intent 过滤器匹配：定位到特定组件的 intent 必须与目标的 intent 过滤器规范完全匹配。如果您发送 intent 来启动其他应用的 activity，目标 intent 组件需要与接收 activity 声明的 intent 过滤器保持一致。
• intent 必须具有操作：没有操作的 intent 将不再与任何 intent 过滤器匹配。这意味着，用于启动 activity 或服务的 intent 必须具有明确定义的操作。

重要提示：PendingIntent 充当标准 Intent 的封装容器，因此这些安全措施适用于 PendingIntent 中包含的 Intent。

如需检查您的应用对这些更改的响应方式，请在应用中使用 StrictMode。如需查看有关 Intent 使用违规行为的详细日志，请添加以下方法：

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 进行了一些更改，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。

Edge-to-edge enforcement

默认情况下，如果应用以 Android 15（API 级别 35）为目标平台，在搭载 Android 15 的设备上，应用默认采用全屏。

重要提示： 如果您的应用尚未采用边到边设计，则应用的部分内容可能会被遮挡，因此您必须处理内边距。这项工作可能很简单，也可能很复杂，具体取决于应用。Material 3 Scaffold 组件可以减少与 Android 15 边到边强制执行兼容所需的工作量。

目标平台为 Android 14 且在 Android 15 设备上未采用边到边设计的应用。

以 Android 15（API 级别 35）为目标平台且在 Android 15 设备上全屏显示的应用。此应用主要使用会自动应用边衬区的 Material 3 Compose 组件。此屏幕不受 Android 15 强制执行的无边框措施的影响。

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。这些变更会影响以下界面区域：

• 手势处理程序导航栏
  • 默认透明。
  • 底部偏移量处于停用状态，因此除非应用边衬区，否则内容会在系统导航栏后面绘制。
  • setNavigationBarColor 和 R.attr#navigationBarColor 已废弃，不会影响手势导航。
  • setNavigationBarContrastEnforced 和 R.attr#navigationBarContrastEnforced 对手势导航的影响仍然不变。
• “三按钮”导航
  • 默认情况下，不透明度设置为 80%，颜色可能与窗口背景相匹配。
  • 底部偏移量处于停用状态，因此除非应用了边衬区，否则内容会在系统导航栏后面绘制。
  • 默认情况下，setNavigationBarColor 和 R.attr#navigationBarColor 会设置为与窗口背景相匹配。窗口背景必须是彩色可绘制对象，此默认值才能应用。此 API 已废弃，但仍会影响三按钮导航。
  • setNavigationBarContrastEnforced 和 R.attr#navigationBarContrastEnforced 默认为 true，这会在“三按钮”导航中添加 80% 的不透明背景。
• 状态栏
  • 默认透明。
  • 顶部偏移量已停用，因此除非应用边衬区，否则内容绘制在状态栏后面。
  • 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，但对 Android 15 仍有影响。
• 刘海屏
  • 非浮动窗口的 layoutInDisplayCutoutMode 必须为 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS。SHORT_EDGES、NEVER 和 DEFAULT 会被解读为 ALWAYS，这样用户就不会看到由刘海屏导致的黑条，从而显示为无边框。

以下示例展示了应用在以 Android 15（API 级别 35）为目标平台之前和之后，以及应用在应用内嵌之前和之后的效果。

目标平台为 Android 14 且在 Android 15 设备上未采用边到边设计的应用。

以 Android 15（API 级别 35）为目标平台且在 Android 15 设备上全屏显示的应用。不过，由于 Android 15 强制执行边到边显示，许多元素现在都被状态栏、三按钮导航栏或显示屏缺口遮挡。隐藏的界面包括 Material 2 顶部应用栏、悬浮操作按钮和列表项。

以 Android 15（API 级别 35）为目标平台的应用，在 Android 15 设备上从边到边，并应用内嵌，以免界面被隐藏。

如何检查应用是否已采用边到边设计

如果您的应用已采用边到边设计并应用了内边距，则除以下情况外，您大多不会受到影响。不过，即使您认为自己未受到影响，我们仍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，这可能是启动画面造成的。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。
• 可能会有流量较低的屏幕显示被遮挡的界面。验证这些访问次数较少的屏幕是否存在遮挡的界面。流量较低的屏幕包括：
  • 初始配置或登录屏幕
  • “设置”页面

如果您的应用尚未采用边到边设计，应检查哪些方面

如果您的应用尚未采用边到边设计，您很可能受到影响。除了已经采用边到边设计的应用的场景之外，您还应考虑以下情况：

• 如果您的应用在 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。
• 如果应用使用的是 Compose 中的 Material 2 组件 (androidx.compose.material)，这些组件本身并不会自动处理边衬区。不过，您可以获得边衬区的访问权限，然后手动应用边衬区。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。
• 如果应用使用了 View 和 Material 组件 (com.google.android.material)，则大多数基于 View 的 Material 组件（例如 BottomNavigationView、BottomAppBar、NavigationRailView 或 NavigationView）都会处理边衬区，因此不需要执行额外的操作。不过，如果使用 AppBarLayout，则需要添加 android:fitsSystemWindows="true"。
• 对于自定义可组合项，请手动将边衬区应用为内边距。如果您的内容位于 Scaffold 中，您可以使用 Scaffold 内边距值使用内边距。否则，请使用 WindowInsets 之一应用内边距。
• 如果应用使用的是 View 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"。

如果您的应用必须提供自定义后台保护，应检查哪些方面

如果您的应用必须为三按钮导航栏或状态栏提供自定义背景保护，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。

其他端到端资源

如需了解有关应用内边距的其他注意事项，请参阅边到边视图和边到边 Compose 指南。

已弃用的 API

以下 API 已废弃，但并未停用：

• R.attr#enforceStatusBarContrast
• R.attr#navigationBarColor（适用于三按钮导航，透明度为 80%）
• Window#isStatusBarContrastEnforced
• Window#setNavigationBarColor（适用于 80% Alpha 版的三按钮导航）
• Window#setStatusBarContrastEnforced

以下 API 已弃用和停用：

• R.attr#navigationBarColor（适用于手势导航）
• R.attr#navigationBarDividerColor
• R.attr#statusBarColor
• Window#setDecorFitsSystemWindows
• Window#getNavigationBarColor
• Window#getNavigationBarDividerColor
• Window#getStatusBarColor
• Window#setNavigationBarColor（适用于手势导航）
• Window#setNavigationBarDividerColor
• Window#setStatusBarColor

Stable configuration

如果您的应用以 Android 15（API 级别 35）或更高版本为目标平台，Configuration 不再排除系统栏。如果您使用 Configuration 类中的屏幕尺寸进行布局计算，应根据需要将其替换为合适的 ViewGroup、WindowInsets 或 WindowMetricsCalculator 等更好的替代方案。

Configuration 从 API 1 开始提供。它通常从 Activity.onConfigurationChanged 中获取。它提供窗口密度、屏幕方向和尺寸等信息。从 Configuration 返回的窗口大小的一个重要特征是，它之前会排除系统栏。

配置大小通常用于资源选择（例如 /res/layout-h500dp），这仍然是一个有效的用例。不过，我们一直不建议将其用于布局计算。如果确实如此，您应暂时放弃。您应根据自己的用例，将 Configuration 的使用替换为更合适的用法。

如果您使用它来计算布局，请使用适当的 ViewGroup，例如 CoordinatorLayout 或 ConstraintLayout。如果您使用它来确定系统侧边栏的高度，请使用 WindowInsets。如果您想知道应用窗口的当前大小，请使用 computeCurrentWindowMetrics。

以下列表介绍了受此变更影响的字段：

• Configuration.screenWidthDp 和 screenHeightDp 尺寸不再排除系统栏。
• Configuration.smallestScreenWidthDp 会间接受到对 screenWidthDp 和 screenHeightDp 的更改的影响。
• 在接近方形的设备上，Configuration.orientation 会间接受到对 screenWidthDp 和 screenHeightDp 所做的更改的影响。
• Display.getSize(Point) 会间接受到 Configuration 中更改的影响。从 API 级别 30 开始，此方法已被弃用。
• 从 API 级别 33 开始，Display.getMetrics() 就已经这样运作了。

elegantTextHeight 属性的默认值为 true

For apps targeting Android 15 (API level 35), 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，某些具有复杂形状的手写字体或语言可能会在上一个或下一个字符的区域绘制字母。在某些情况下，此类字母会在开头或结尾处被剪裁。从 Android 15 开始，TextView 会分配宽度，以便为此类字母绘制足够的空间，并允许应用请求向左额外添加内边距以防止剪裁。

由于此更改会影响 TextView 确定宽度的方式，因此如果应用以 Android 15（API 级别 35）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。

由于添加左内边距可能会导致现有布局未对齐，因此默认情况下不会添加内边距，即使以 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剪裁。

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。

采用手写体字体的英语文本的标准布局。部分字母被截断。对应的 XML 如下：

<TextView
    android:fontFamily="cursive"
    android:text="java" />

相同英语文本的布局，增加了宽度和内边距。以下是相应的 XML：

<TextView
    android:fontFamily="cursive"
    android:text="java"
    android:useBoundsForWidth="true"
    android:shiftDrawingOffsetForStartOverhang="true" />

泰语文本的标准布局。部分字母被截断。 以下是相应的 XML：

<TextView
    android:text="คอมพิวเตอร์" />

相同泰语文本的布局，增加了宽度和内边距。以下是相应的 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 (API level 35), 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。

有关请求音频焦点的限制

以 Android 15 为目标平台的应用必须是顶级应用或运行前台服务，才能请求音频焦点。如果应用在不符合其中任何一项要求时尝试请求焦点，该调用将返回 AUDIOFOCUS_REQUEST_FAILED。

您可以参阅管理音频焦点，详细了解音频焦点。

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.

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。