行為變更：指定 Android 15 以上版本的應用程式

和先前版本一樣，Android 15 也包含可能會影響應用程式的行為變更。以下行為變更僅適用於指定 Android 15 以上版本的應用程式。如果應用程式指定 Android 15 以上版本，建議您視情況修改應用程式，以支援這些行為。

此外，無論應用程式的 targetSdkVersion 為何，請務必查看影響所有在 Android 15 上執行的應用程式行為變更清單。

核心功能

Android 15 修改或擴充 Android 系統的各種核心功能。

前景服務變更

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

• New media processing foreground service type
• Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services

Data sync foreground service timeout behavior

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]"

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 推出了新的前景服務類型 mediaProcessing。這個服務類型適用於轉碼媒體檔案等作業。舉例來說，媒體應用程式可能會下載音訊檔案，需要將其轉換成其他格式後再播放。您可以使用 mediaProcessing 前景服務，確保即使應用程式在背景執行時，轉換仍能持續。

系統允許應用程式的 mediaProcessing 服務在 24 小時內執行共計 6 小時，之後系統會呼叫執行中服務的 Service.onTimeout(int, int) 方法 (在 Android 15 中導入)。此時，服務有幾秒鐘的時間可以呼叫 Service.stopSelf()。如果服務未呼叫 Service.stopSelf()，系統會擲回內部例外狀況。例外狀況會記錄在 Logcat 中，並附帶以下訊息：

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

為避免例外狀況，您可以採取下列其中一種做法：

1. 讓您的服務實作新的 Service.onTimeout(int, int) 方法。應用程式收到回呼時，請務必在幾秒內呼叫 stopSelf()。(如果您沒有立即停止應用程式，系統會產生失敗情形)。
2. 確認應用程式的 mediaProcessing 服務在 24 小時內總計不會超過 6 小時 (除非使用者與應用程式互動，並重設計時器)。
3. 只有在使用者直接互動時才啟動 mediaProcessing 前景服務；由於您的應用程式在服務啟動後位於前景，因此應用程式進入背景後，您的服務有完整的六小時資訊。
4. 請使用替代 API，例如 WorkManager，不要使用 mediaProcessing 前景服務。

如果應用程式的 mediaProcessing 前景服務在過去 24 天內已執行 6 小時，則「除非」使用者將應用程式移至前景 (這會重設計時器)，否則您無法啟動另一項 mediaProcessing 前景服務。如果您嘗試啟動另一項 mediaProcessing 前景服務，系統會擲回 ForegroundServiceStartNotAllowedException，並顯示錯誤訊息「Time limit is Of for 前景服務類型 mediaProcessing」

如要進一步瞭解 mediaProcessing 服務類型，請參閱「Android 15 前景服務類型變更：媒體處理」。

測試

為了測試應用程式的行為，即使應用程式並非以 Android 15 為目標版本 (前提是應用程式在 Android 15 裝置上執行)，則可以啟用媒體處理逾時。如要啟用逾時，請執行下列 adb 指令：

adb shell am compat enable FGS_INTRODUCE_TIME_LIMITS your-package-name

您也可以調整逾時期限，方便測試應用程式在達到上限時的行為。如要設定新的逾時期限，請執行下列 adb 指令：

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

之前，即使應用程式擁有 SYSTEM_ALERT_WINDOW 權限，即使應用程式目前在背景中，系統仍會啟動前景服務 (如「不受背景啟動限制的豁免項目」所述)。

如果應用程式以 Android 15 為目標版本，則這項豁免權現在的範圍較小。應用程式現在需要 SYSTEM_ALERT_WINDOW 權限，且還要顯示可見的疊加層視窗。也就是說，應用程式必須先啟動 TYPE_APPLICATION_OVERLAY 視窗，而且需要顯示視窗，才能啟動前景服務。

如果應用程式不符合這些新規定，且嘗試從背景啟動前景服務 (且沒有其他豁免情況)，系統會擲回 ForegroundServiceStartNotAllowedException。

如果應用程式宣告 SYSTEM_ALERT_WINDOW 權限，並從背景啟動前景服務，可能就會受到這項異動影響。如果您的應用程式取得 ForegroundServiceStartNotAllowedException，請檢查應用程式的作業順序，並確認應用程式具備有效的重疊視窗，然後再嘗試從背景啟動前景服務。您可以呼叫 View.getWindowVisibility() 來檢查重疊視窗目前是否可見，也可以覆寫 View.onWindowVisibilityChanged()，在瀏覽權限變更時接收通知。

應用程式何時可修改「零打擾」模式的全域狀態異動

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 變更

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();
  }
  

安全性

Android 15 包含提升系統安全性的異動，可協助保護應用程式和使用者不受惡意應用程式侵擾。

啟動安全的背景活動

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.

更安全的意圖

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

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

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

使用者體驗和系統 UI

Android 15 包含一些變更，旨在打造更一致且符合直覺的使用者體驗。

視窗插邊變更

Android 15 的視窗插邊有兩項變更：根據預設，系統會強制執行無邊框設計，以及設定變更 (例如系統列的預設設定)。

Edge-to-edge enforcement

在搭載 Android 15 的裝置上，應用程式預設為無邊框設計 指定 Android 15 (API 級別 35) 為目標。

以 Android 14 為目標版本，且非採用無邊框設計的應用程式

這項破壞性變更可能會對應用程式的 UI 造成負面影響。 變更會影響下列 UI 區域：

• 手勢控點導覽列
  • 預設為透明。
  • 已停用底部偏移，因此內容會在系統導覽後繪製 除非套用插邊
  • setNavigationBarColor和R.attr#navigationBarColor是 且不會影響手勢操作模式。
  • setNavigationBarContrastEnforced 和 R.attr#navigationBarContrastEnforced 繼續於 以及手勢操作
• 三按鈕操作
  • 根據預設，透明度會設為 80%，色彩可能會與視窗相符 背景。
  • 已停用底部偏移，因此內容會在系統導覽列後方繪製 除非套用了插邊
  • setNavigationBarColor和R.attr#navigationBarColor是 設定為符合視窗背景。視窗背景 必須是顏色可繪項目，才能套用此預設值。這個 API 但會繼續影響三按鈕操作
  • setNavigationBarContrastEnforced 和 根據預設，R.attr#navigationBarContrastEnforced 為 true，因此系統會新增 三按鈕操作模式下的不透明背景：80%。
• 狀態列
  • 預設為透明。
  • 系統會停用頂部位移，因此內容會在狀態列後方繪製，除非 則套用插邊。
  • setStatusBarColor和R.attr#statusBarColor是 並且對 Android 15 沒有任何影響。
  • setStatusBarContrastEnforced 和 R.attr#statusBarContrastEnforced 已淘汰，但仍有 在 Android 15 上生效
• 螢幕凹口
  • 非浮動視窗的值必須為 layoutInDisplayCutoutMode LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS。SHORT_EDGES、NEVER和 系統會將 DEFAULT 解讀為 ALWAYS，因此使用者不會看見黑色 顯示出「無邊框」提示。

以下範例是指定前後對照的應用程式 Android 15 (API 級別 35) 及套用插邊前後的版本。

以 Android 14 為目標版本，且非採用無邊框設計的應用程式

以 Android 15 (API 級別 35) 為目標版本的應用程式採用無邊框設計。

要檢查應用程式是否已採用無邊框設計

如果您的應用程式已經採用無邊框設計，並套用插邊，那麼您 影響程度最高，不過下列情況除外。即使您認為 您不妨測試應用程式。

• 您有非浮動視窗，例如使用Activity 使用 SHORT_EDGES、NEVER 或 DEFAULT 取代 LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS。如果您的應用程式在啟動時異常終止， 這可能是因為啟動畫面所致您可將核心肌群 splashscreen 依附元件至 1.2.0-alpha01 或之後設定 window.attributes.layoutInDisplayCutoutMode = WindowManager.LayoutInDisplayCutoutMode.always。
• 部分流量較低的畫面可能會遭遮蔽，驗證這些 較少造訪的畫面沒有遮蔽 UI。低流量畫麵包括：
  • 登入或登入畫面
  • 設定頁面

檢查應用程式是否為無邊框應用程式的方法

如果您的應用程式尚未採用無邊框設計，那麼您很有可能受到影響。於 除了採用無邊框設計的應用程式相關情境外 請考慮以下幾點：

• 如果您的應用程式使用 Material 3 元件 ( androidx.compose.material3) 在 Compose 中，例如 TopAppBar BottomAppBar 和 NavigationBar，這些元件可能不 會自動處理插邊。
• 如果應用程式使用 Material 2 元件 ( androidx.compose.material) 就不會自動處理插邊不過，您可以存取插邊 並手動套用在 androidx.compose.material 1.6.0 中 然後，使用 windowInsets 參數手動套用插邊 BottomAppBar、TopAppBar、 BottomNavigation和 NavigationRail。 同樣地，對以下項目使用 contentWindowInsets 參數： Scaffold.
• 如果應用程式使用檢視畫面和 Material 元件 (com.google.android.material)，多數以檢視畫面為基礎的 Material BottomNavigationView、BottomAppBar 等元件 NavigationRailView 或 NavigationView，處理插邊，且不需要 其他作業不過，您需要新增 android:fitsSystemWindows="true" 若使用 AppBarLayout。
• 如果是自訂可組合項，請手動將插邊套用為邊框間距。如果您的 在 Scaffold 內的內容，您可以使用 Scaffold 取用插邊 邊框間距值。否則，請使用 WindowInsets.
• 如果應用程式使用 View 和 BottomSheet、SideSheet 或自訂 來套用邊框間距 ViewCompat.setOnApplyWindowInsetsListener。適用對象 RecyclerView，使用這個事件監聽器套用邊框間距，同時新增 clipToPadding="false"。

檢查應用程式是否必須提供自訂背景保護的事項

如果您的應用程式必須在三按鈕操作模式下提供自訂背景保護措施 狀態列時，應用程式應將可組合項或檢視畫面放置在系統列後方 使用 WindowInsets.Type#tappableElement() 取得 3 按鈕 導覽列高度或 WindowInsets.Type#statusBars。

其他無邊框資源

詳情請參閱「Edge to Edge View」和「Edge to Edge Compose」 指南。

已淘汰的 API

下列 API 現已淘汰：

• 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

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.

routeTextHeight 屬性預設為 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.

針對複雜的字母形狀變更 TextView 寬度

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 可感知本地化的預設行高

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:

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:

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.

相機與媒體

Android 15 針對指定 Android 15 以上版本為目標的應用程式，對相機和媒體行為做出下列變更。

要求音訊焦點的限制

以 Android 15 為目標的應用程式必須是頂層應用程式或執行前景服務，才能要求音訊焦點。如果應用程式嘗試要求焦點，但不符合上述其中一項要求，呼叫會傳回 AUDIOFOCUS_REQUEST_FAILED。

如要進一步瞭解音訊焦點，請參閱管理音訊焦點一文。

更新非 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.