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.

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。此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，因此必須先將其轉換為其他格式才能播放。您可以使用 mediaProcessing 前景服務，確保即使應用程式在背景執行，轉換作業仍會持續。

系統允許應用程式的 mediaProcessing 服務在 24 小時內總共執行 6 小時，之後系統會呼叫執行中服務的 Service.onTimeout(int, int) 方法 (於 Android 15 中導入)。目前，服務有幾秒鐘才能呼叫 Service.stopSelf()。如果服務未呼叫 Service.stopSelf()，就會發生錯誤，並顯示以下錯誤訊息：「<fgs_type> 的前景服務並未在逾時內停止：<component_name>」。在 Beta 版 2 中，失敗訊息會顯示為 ANR，但在日後的 Beta 版中，這個失敗訊息會擲回自訂例外狀況。

如要避免發生 ANR，您可以採取下列任一做法：

  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()。(如果您未立即停止應用程式，系統會產生失敗)。
  2. 請確保應用程式的 mediaProcessing 服務在 24 小時內不會執行超過總計 6 小時 (除非使用者與應用程式互動、重設計時器)。
  3. 只有在使用者直接互動後，才啟動 mediaProcessing 前景服務；由於服務在服務啟動時位於前景，因此服務在應用程式進入背景後可持續六小時。
  4. 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 內已執行 6 小時，則「除非」使用者將應用程式移至前景 (重設計時器)，否則您無法啟動其他 mediaProcessing 前景服務。如果您嘗試啟動另一個 mediaProcessing 前景服務，系統會擲回 ForegroundServiceStartNotAllowedException 並顯示錯誤訊息，例如「Time limit is outed on 自動調整 service type 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」。

Restrictions on BOOT_COMPLETED broadcast receivers launching foreground services

There are new restrictions on BOOT_COMPLETED broadcast receivers launching foreground services. BOOT_COMPLETED receivers are not allowed to launch the following types of foreground services:

If a BOOT_COMPLETED receiver tries to launch any of those types of foreground services, the system throws ForegroundServiceStartNotAllowedException.

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

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 17 變更

Android 15 會繼續更新 Android 核心程式庫，以便與最新版 OpenJDK LTS 中的功能保持一致。

其中一項變更可能會影響指定 Android 15 的應用程式相容性：

  • 字串格式 API 變更：現在使用下列 String.format() 和 Formatter.format() API 時，引數索引、標記、寬度和精確度的驗證作業更加嚴格：

    舉例來說，如果使用引數索引 0 (格式字串中的 %0)，系統會擲回以下例外狀況：

    IllegalFormatArgumentIndexException: Illegal format argument index = 0

    在這種情況下，您可以使用引數索引 1 修正此問題 (格式字串中的 %1)。

  • Arrays.asList(...).toArray() 的元件類型變更：使用 Arrays.asList(...).toArray() 時，產生的陣列的元件類型現在是 Object，而非基礎陣列元素的類型。因此，以下程式碼會擲回 ClassCastException：

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

    在此情況下，如果想在結果陣列中保留 String 做為元件類型，您可以改用 Collection.toArray(Object[])：

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

  • 語言代碼變更：使用 Locale API 時，希伯來文、意第緒文和印尼文的語言代碼不會再轉換為過時形式 (希伯來文：iw、Yiddish：ji 和印尼文：in)。 指定其中一個語言代碼的語言代碼時，請改用 ISO 639ish-1 和 印尼文 (希伯來文)：he、印尼文、印尼文 (12)。yiid

  • 隨機連續序列的變更：完成 https://bugs.openjdk.org/browsing/JDK-8301574 變更後，下列 Random.ints() 方法會傳回與 Random.nextInt() 方法不同的數字序列：

    一般而言，這項變更應該不會導致應用程式破壞行為，但您的程式碼不應預期從 Random.ints() 方法產生的順序與 Random.nextInt() 相符。

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

Kotlin


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

Java


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

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

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

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:

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:

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.

elegantTextHeight behavior for apps targeting Android 14 (API level 34) and lower.
elegantTextHeight behavior for apps targeting Android 15.

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:

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.

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

Apps that target Android 15 must be the top app or running an audio-related foreground service in order to request audio focus. If an app attempts to request focus when it does not meet one of these requirements, the call returns AUDIOFOCUS_REQUEST_FAILED.

A foreground service is considered audio-related if its type is mediaPlayback, camera, microphone, or phoneCall.

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

更新非 SDK 限制

基於與 Android 開發人員合作及最新的內部測試，Android 15 包含更新後的受限制非 SDK 介面清單。在限制非 SDK 介面之前，我們盡可能確保公開替代方案的可得性。

如果您的應用程式並不是以 Android 15 為目標版本，則此處所述的某些變更可能不會立即對您造成影響。不過，視應用程式的目標 API 級別而定，應用程式可以存取部分非 SDK 介面，但使用任何非 SDK 方法或欄位時，都會面臨應用程式停止運作的高度風險。

如果不確定應用程式是否使用非 SDK 介面，可測試應用程式以便確認。如果您的應用程式仰賴非 SDK 介面，則建議您開始規劃遷移至 SDK 替代方案。我們瞭解有些應用程式可使用非 SDK 介面的有效用途。如果您除了為應用程式中的某個功能使用非 SDK 介面外，已別無他法，則應要求新的公用 API。

如要進一步瞭解此 Android 版本中的變更，請參閱 Android 15 的非 SDK 介面限制更新內容。如要進一步瞭解非 SDK 介面的一般資訊，請參閱非 SDK 介面的限制。