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:
- Have your service implement the new
Service.onTimeout(int, int)
method. When your app receives the callback, make sure to callstopSelf()
within a few seconds. (If you don't stop the app right away, the system generates a failure.) - 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). - 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. - 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:
- 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)。 - 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)。 - 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。 - 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 formicrophone
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
以 Android 15 为目标平台的应用无法再更改设备上的全局状态或勿扰 (DND) 政策(通过修改用户设置或关闭 DND 模式)。相反,应用必须提供一个 AutomaticZenRule
,系统会将后者合并到一个具有现有最严格的政策胜出方案的全局政策中。调用之前影响全局状态的现有 API(setInterruptionFilter
、setNotificationPolicy
)会导致创建或更新隐式 AutomaticZenRule
,该 AutomaticZenRule
根据这些 API 调用的调用周期而开启或关闭。
请注意,只有在应用调用 setInterruptionFilter(INTERRUPTION_FILTER_ALL)
且预期调用会停用之前由其所有者激活的 AutomaticZenRule
时,此变更才会影响可观察的行为。
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()
andFormatter.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 usingArrays.asList(...).toArray()
, the component type of the resulting array is now anObject
—not the type of the underlying array's elements. So the following code throws aClassCastException
:String[] elements = (String[]) Arrays.asList("one", "two").toArray();
For this case, to preserve
String
as the component type in the resulting array, you could useCollection.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 theRandom.nextInt()
methods do:Generally, this change shouldn't result in app-breaking behavior, but your code shouldn't expect the sequence generated from
Random.ints()
methods to matchRandom.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()
andMutableList.removeLast()
extension functions inkotlin-stdlib
The
List
type in Java is mapped to theMutableList
type in Kotlin. Because theList.removeFirst()
andList.removeLast()
APIs have been introduced in Android 15 (API level 35), the Kotlin compiler resolves function calls, for examplelist.removeFirst()
, statically to the newList
APIs instead of to the extension functions inkotlin-stdlib
.If an app is re-compiled with
compileSdk
set to35
andminSdk
set to34
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()
andremoveLast()
function calls can be replaced withremoveAt(0)
andremoveAt(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")
andlintOptions { 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
andDeque
. 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, thejavac
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 ListExample 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 errorExample 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 errorTo 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 aPendingIntent
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 引入了新的安全措施,使 intent 更加安全可靠。这些变更旨在防止潜在漏洞和被恶意应用利用的 intent 滥用。Android 15 中对 intent 的安全性进行了两项主要改进:
- 匹配目标 intent 过滤器:定位特定组件的 intent 必须准确匹配目标的 intent 过滤器规范。如果您通过发送 intent 来启动其他应用的 activity,则目标 intent 组件需要与接收 activity 声明的 intent 过滤器保持一致。
- intent 必须具有操作:没有操作的 intent 将不再与任何 intent 过滤器匹配。这意味着,用于启动 activity 或服务的 intent 必须具有明确定义的操作。
- 待处理 intent:待处理 intent 的创建者被视为封装 intent 的发送者,而非待处理 intent 的发送者
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
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)。
全面强制执行
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。
![](https://developer.android.google.cn/static/about/versions/15/images/edge-to-edge-1.png?authuser=0000&hl=zh-tw)
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。
- 非浮動視窗的值必須為
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。
![](https://developer.android.google.cn/static/about/versions/15/images/edge-to-edge-4.png?authuser=0000&hl=zh-tw)
![](https://developer.android.google.cn/static/about/versions/15/images/edge-to-edge-6.png?authuser=0000&hl=zh-tw)
![](https://developer.android.google.cn/static/about/versions/15/images/edge-to-edge-2.png?authuser=0000&hl=zh-tw)
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 MaterialBottomNavigationView
、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
稳定配置
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
andscreenHeightDp
sizes no longer exclude the system bars.Configuration.smallestScreenWidthDp
is indirectly affected by changes toscreenWidthDp
andscreenHeightDp
.Configuration.orientation
is indirectly affected by changes toscreenWidthDp
andscreenHeightDp
on close-to-square devices.Display.getSize(Point)
is indirectly affected by the changes inConfiguration
. 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
对于以 Android 15 为目标平台的应用,elegantTextHeight
TextView
属性默认变为 true
,将默认使用的紧凑字体替换为一些具有较大垂直指标的脚本,并且这种字体更易于阅读。紧凑字体的引入是为了防止破坏布局;Android 13(API 级别 33)允许文本布局利用 fallbackLineSpacing
属性拉伸垂直高度,以防止许多此类破坏。
在 Android 15 中,紧凑字体仍保留在系统中,因此您的应用可以将 elegantTextHeight
设置为 false
,以获得与之前相同的行为,但即将在未来版本中提供支持。因此,如果您的应用支持以下文字:阿拉伯语、老挝语、缅甸、泰米尔语、古吉拉特语、卡纳达语、马拉雅拉姆语、奥里亚语、泰卢固语或泰语,请将 elegantTextHeight
设置为 true
,以测试应用。
![](https://developer.android.google.cn/static/about/versions/15/images/elegant-text-height-before.png?authuser=0000&hl=zh-tw)
elegantTextHeight
行为。![](https://developer.android.google.cn/static/about/versions/15/images/elegant-text-height-after.png?authuser=0000&hl=zh-tw)
elegantTextHeight
行为。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.
![](https://developer.android.google.cn/static/about/versions/15/images/cursive-clipped.png?authuser=0000&hl=zh-tw)
<TextView android:fontFamily="cursive" android:text="java" />
![](https://developer.android.google.cn/static/about/versions/15/images/cursive-noclipping.png?authuser=0000&hl=zh-tw)
<TextView android:fontFamily="cursive" android:text="java" android:useBoundsForWidth="true" android:shiftDrawingOffsetForStartOverhang="true" />
![](https://developer.android.google.cn/static/about/versions/15/images/thai-clipped.png?authuser=0000&hl=zh-tw)
<TextView android:text="คอมพิวเตอร์" />
![](https://developer.android.google.cn/static/about/versions/15/images/thai-noclipping.png?authuser=0000&hl=zh-tw)
<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:
![](https://developer.android.google.cn/static/about/versions/15/images/locale-aware-line-height-before.png?authuser=0000&hl=zh-tw)
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:
![](https://developer.android.google.cn/static/about/versions/15/images/locale-aware-line-height-after.png?authuser=0000&hl=zh-tw)
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
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.
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。