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 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]"

Note: The 6-hour time limit is shared by all of an app's mediaProcessing foreground services. For example, if an app runs a mediaProcessing service for four hours, then starts a different mediaProcessing 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 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:

• 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 introduces new optional 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.

Important: A PendingIntent acts as a wrapper for a standard Intent, so these security measures apply to the Intent contained within the PendingIntent.

In order to check how your app responds to these changes, use StrictMode in your app. To see detailed logs about Intent usage violations, add the following method:

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

There are two changes related to window insets in Android 15: edge-to-edge is enforced by default, and there are also configuration changes, such as the default configuration of system bars.

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

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:

• Configuration.screenWidthDp and screenHeightDp sizes no longer exclude the system bars.
• Configuration.smallestScreenWidthDp is indirectly affected by changes to screenWidthDp and screenHeightDp.
• Configuration.orientation is indirectly affected by changes to screenWidthDp and screenHeightDp on close-to-square devices.
• Display.getSize(Point) is indirectly affected by the changes in Configuration. This was deprecated beginning in API level 30.
• Display.getMetrics() has already worked like this since API level 33.

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

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 (API level 35) 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 (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.

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.