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

我们将在 Android 15 中对前台服务进行以下更改。

• 数据同步前台服务超时行为
• 新媒体处理前台服务类型
• 对启动前台服务的 BOOT_COMPLETED 广播接收器的限制
• 针对在应用拥有 SYSTEM_ALERT_WINDOW 权限时启动前台服务的限制

数据同步前台服务超时行为

Android 15 introduces a new timeout behavior to dataSync for apps targeting Android 15 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

新建媒体处理前台服务类型

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

对启动前台服务的 BOOT_COMPLETED 广播接收器实施限制

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

限制在应用拥有 SYSTEM_ALERT_WINDOW 权限时启动前台服务

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 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.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 可保护用户免受恶意应用的侵害，并让用户更好地控制 来防止恶意后台应用 将其他应用置于前台、提升其权限以及滥用 用户互动自以下时间以来，后台活动启动一直受到限制 Android 10（API 级别 29）。

禁止与堆栈中的顶部 UID 不匹配的应用启动 activity

恶意应用可以在同一任务中启动另一个应用的 activity，然后 叠加在上面，营造出像该应用一样的错觉。这个“任务” 劫持"攻击绕过了当前的后台启动限制， 会发生在同一个可见任务中。为了降低这种风险，Android 15 新增了 用于阻止与堆栈中的顶层 UID 不匹配的应用启动的标志 活动。如需选择启用应用的所有活动，请更新 allowCrossUidActivitySwitchFromBelow 属性：AndroidManifest.xml

<application android:allowCrossUidActivitySwitchFromBelow="false" >

如果满足以下所有条件，则启用新的安全措施：

• 执行启动的应用以 Android 15 为目标平台。
• 任务堆栈顶部的应用以 Android 15 为目标平台。
• 所有可见活动都已选择启用新保护措施

如果启用了安全措施，应用可能会返回主屏幕，而不是返回 最后一个可见应用（如果他们自行完成任务）。

其他变更

除了限制 UID 匹配之外，这些其他变更也 包括：

• 更改 PendingIntent 创作者，以阻止后台活动启动，具体方法是： 默认。这有助于防止应用意外创建 可能被恶意操作者滥用的 PendingIntent。
• 请勿将应用调到前台，除非 PendingIntent 发送者 允许它。此变更旨在防止恶意应用滥用 在后台启动 activity 的功能。默认情况下，应用 允许将任务堆栈转到前台，除非创建者允许 后台活动启动权限或发送者有后台活动 启动权限
• 控制任务堆栈的顶层 activity 完成其任务的方式。如果 顶层 activity 完成一项任务后，Android 会返回到之前执行的 上次活动时间。此外，如果非顶层 activity 完成其任务，Android 将 返回主屏幕；因此不会阻碍这个非顶层的 活动。
• 防止将其他应用中的任意 activity 启动到您自己的 activity 任务。这项变更旨在防止恶意应用 看起来像是来自其他应用的活动
• 禁止将不可见窗口视为后台活动 发布。这有助于防止恶意应用滥用后台 activity 来向用户显示不需要或恶意的内容。

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

Important: Strict Mode can be enabled to help catch potential issues 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 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。

全面强制执行

Apps are edge-to-edge by default on devices running Android 15 if the app is targeting Android 15 (API level 35).

Important: If your app is not already edge-to-edge, portions of your app may be obscured and you must handle insets. Depending on the app, this work may or may not be significant. The Material 3 Scaffold component can reduce the work required to be compatible with the Android 15 edge-to-edge enforcement.

An app that targets Android 14 and is not edge-to-edge on an Android 15 device.

An app that targets Android 15 (API level 35) and is edge-to-edge on an Android 15 device. This app mostly uses Material 3 Compose Components that automatically apply insets. This screen is not negatively impacted by the Android 15 edge-to-edge enforcement.

This is a breaking change that might negatively impact your app's UI. The changes affect the following UI areas:

• Gesture handle navigation bar
  • Transparent by default.
  • Bottom offset is disabled so content draws behind the system navigation bar unless insets are applied.
  • setNavigationBarColor and R.attr#navigationBarColor are deprecated and don't affect gesture navigation.
  • setNavigationBarContrastEnforced and R.attr#navigationBarContrastEnforced continue to have no effect on gesture navigation.
• 3-button navigation
  • Opacity set to 80% by default, with color possibly matching the window background.
  • Bottom offset disabled so content draws behind the system navigation bar unless insets are applied.
  • setNavigationBarColor and R.attr#navigationBarColor are set to match the window background by default. The window background must be a color drawable for this default to apply. This API is deprecated but continues to affect 3-button navigation.
  • setNavigationBarContrastEnforced and R.attr#navigationBarContrastEnforced is true by default, which adds an 80% opaque background across 3-button navigation.
• Status bar
  • Transparent by default.
  • The top offset is disabled so content draws behind the status bar unless insets are applied.
  • setStatusBarColor and R.attr#statusBarColor are deprecated and have no effect on Android 15.
  • setStatusBarContrastEnforced and R.attr#statusBarContrastEnforced are deprecated but still have an effect on Android 15.
• Display cutout
  • layoutInDisplayCutoutMode of non-floating windows must be LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS. SHORT_EDGES, NEVER and DEFAULT are interpreted as ALWAYS so that users don't see a Black bar caused by the display cutout and appear edge-to-edge.

The following example shows an app before and after targeting Android 15 (API level 35), and before and after applying insets.

An app that targets Android 14 and is not edge-to-edge on an Android 15 device.

An app that targets Android 15 (API level 35) and is edge-to-edge on an Android 15 device. However, many elements are now hidden by the status bar, 3-button navigation bar, or display cutout due to the Android 15 edge-to-edge enforcements. Hidden UI includes the Material 2 top app bar, floating action buttons, and list items.

An app that targets Android 15 (API level 35), is edge to edge on an Android 15 device and applies insets so that UI is not hidden.

What to check if your app is already edge-to-edge

If your app is already edge-to-edge and applies insets, you are mostly unimpacted, except in the following scenarios. However, even if you think you aren't impacted, we recommend you test your app.

• You have a non-floating window, such as an Activity that uses SHORT_EDGES, NEVER or DEFAULT instead of LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS. If your app crashes on launch, this might be due to your splashscreen. You can either upgrade the core splashscreen dependency to 1.2.0-alpha01 or later or set window.attributes.layoutInDisplayCutoutMode = WindowManager.LayoutInDisplayCutoutMode.always.
• There might be lower-traffic screens with occluded UI. Verify these less-visited screens don't have occluded UI. Lower-traffic screens include:
  • Onboarding or sign-in screens
  • Settings pages

What to check if your app is not already edge-to-edge

If your app is not already edge-to-edge, you are most likely impacted. In addition to the scenarios for apps that are already edge-to-edge, you should consider the following:

• If your app uses Material 3 Components ( androidx.compose.material3) in compose, such as TopAppBar, BottomAppBar, and NavigationBar, these components are likely not impacted because they automatically handle insets.
• If your app is using Material 2 Components ( androidx.compose.material) in Compose, these components don't automatically handle insets. However, you can get access to the insets and apply them manually. In androidx.compose.material 1.6.0 and later, use the windowInsets parameter to apply the insets manually for BottomAppBar, TopAppBar, BottomNavigation, and NavigationRail. Likewise, use the contentWindowInsets parameter for Scaffold.
• If your app uses views and Material Components (com.google.android.material), most views-based Material Components such as BottomNavigationView, BottomAppBar, NavigationRailView, or NavigationView, handle insets and require no additional work. However, you need to add android:fitsSystemWindows="true" if using AppBarLayout.
• For custom composables, apply the insets manually as padding. If your content is within a Scaffold, you can consume insets using the Scaffold padding values. Otherwise, apply padding using one of the WindowInsets.
• If your app is using views and BottomSheet, SideSheet or custom containers, apply padding using ViewCompat.setOnApplyWindowInsetsListener. For RecyclerView, apply padding using this listener and also add clipToPadding="false".

What to check if your app must offer custom background protection

If your app must offer custom background protection to 3-button navigation or the status bar, you app should place a composable or view behind the system bar using WindowInsets.Type#tappableElement() to get the 3-button navigation bar height or WindowInsets.Type#statusBars.

Additional edge-to-edge resources

See the Edge to Edge Views and Edge to Edge Compose guides for additional considerations on applying insets.

Deprecated APIs

The following APIs are now deprecated:

• R.attr#enforceStatusBarContrast
• R.attr#navigationBarColor
• R.attr#navigationBarDividerColor
• R.attr#statusBarColor
• Window#getNavigationBarColor
• Window#getNavigationBarDividerColor
• Window#getStatusBarColor
• Window#isStatusBarContrastEnforced
• Window#setDecorFitsSystemWindows
• Window#setNavigationBarColor
• Window#setNavigationBarDividerColor
• Window#setStatusBarColor
• Window#setStatusBarContrastEnforced

稳定配置

如果您的应用以 Android 15（API 级别 35）或更高版本为目标平台，Configuration 否 不再包含系统栏。如果您使用 Configuration 类，您应将其替换为更好的 相应的 ViewGroup、WindowInsets 或 WindowMetricsCalculator，具体取决于您的需求。

Configuration 从 API 1 开始提供。它通常从 Activity.onConfigurationChanged.它提供窗口密度、 屏幕方向和尺寸窗口大小的一个重要特征 Configuration 之前会排除系统栏。

配置大小通常用于选择资源，例如 /res/layout-h500dp，这仍然是一个有效的用例。但将其用于 但一直不建议进行布局计算。如果需要，您应该将 现在离它远去。您应该使用 Configuration 具体取决于您的应用场景。

如果使用它来计算布局，请使用适当的 ViewGroup，例如 CoordinatorLayout 或 ConstraintLayout。如果使用该属性确定高度 ，请使用 WindowInsets。如果您想知道当前尺寸 ，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受到更改的间接影响 发送给screenWidthDp和screenHeightDp。
• Configuration.orientation受到以下项的更改间接影响： screenWidthDp 和 screenHeightDp，在近似方形设备上显示。
• Display.getSize(Point)会间接受到 Configuration。从 API 级别 30 开始，此 API 已废弃。
• 从 API 级别 33 开始，Display.getMetrics() 已采用这种方式。

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

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

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 包含更新后的受限非 SDK 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，使用任何非 SDK 均可 方法或字段总是很有破坏应用的风险。

如果您不确定自己的应用是否使用了非 SDK 接口，可以 测试您的应用，找出答案。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。 尽管如此，我们了解到，某些应用具有 非 SDK 接口。如果您无法找到使用非 SDK 的替代方案 应用某项功能的界面，您应该 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。