功能與 API 總覽

Android 14 為開發人員推出了強大的功能和 API。以下可協助您瞭解應用程式功能,並開始使用相關的 API。

如需新增、修改及移除 API 的詳細清單,請參閱 API 差異比較報表。如要進一步瞭解新增的 API,請參閱「Android API 參考資料」一文;如果是 Android 14,請查看在 API 級別 34 中新增的 API。如要瞭解平台變更可能會影響應用程式的哪些方面,請務必查看指定 Android 14 為目標版本的應用程式所有應用程式適用的 Android 14 行為變更。

國際化

個別應用程式語言偏好

Android 14 則進一步擴充 Android 13 (API 級別 33) 所推出的個別應用程式語言功能,並提供下列額外功能:

  • 自動產生應用程式的 localeConfig:自 Android Studio Giraffe Canary 7 和 AGP 8.1.0-alpha07 起,您可以將應用程式設為自動支援個別應用程式語言偏好設定。Android Gradle 外掛程式會根據您的專案資源產生 LocaleConfig 檔案,並在最終資訊清單檔案中加入該檔案的參照,為您省去手動建立或更新檔案的需求。AGP 會使用應用程式模組 res 資料夾中的資源和任何程式庫模組依附元件,決定要納入 LocaleConfig 檔案的語言代碼。

  • 應用程式的 localeConfig 動態更新:在 LocaleManager 中使用 setOverrideLocaleConfig()getOverrideLocaleConfig() 方法,可在裝置的系統設定中動態更新應用程式支援的語言清單。如果應用程式使用伺服器端推送進行本地化,則可利用此彈性自訂各區域的支援語言清單、執行 A/B 實驗,或提供更新的語言代碼清單。

  • 輸入法編輯器 (IME) 的應用程式語言瀏覽權限:輸入法編輯器可透過 getApplicationLocales() 方法檢查目前應用程式的語言,並和輸入法編輯器的語言進行比對。

文法轉變 API

30 億人使用性別化語言:即名詞、動詞、形容詞和介系詞會隨著交談或談論對像或目標的性別,而有不同變化的文法類別語言。一般來說,許多性別化語言都會使用陽性文法性別做為預設或通用性別。

若以錯誤的文法性別稱呼使用者,例如:以陽性文法性別稱呼女性,可能會對其表現和態度產生負面影響。相反地,如果使用者介面的用語正確反映了使用者的文法性別,便可提高使用者參與度,同時提供更個人化且更自然親切的使用者體驗。

為了協助你針對使用文法性別的語言,建構以使用者為中心的使用者介面,Android 14 採用了文法轉變 API,可讓你新增對文法性別的支援,而不必重構應用程式。

地區偏好設定

Regional preferences enable users to personalize temperature units, the first day of the week, and numbering systems. A European living in the United States might prefer temperature units to be in Celsius rather than Fahrenheit and for apps to treat Monday as the beginning of the week instead of the US default of Sunday.

New Android Settings menus for these preferences provide users with a discoverable and centralized location to change app preferences. These preferences also persist through backup and restore. Several APIs and intents—such as getTemperatureUnit and getFirstDayOfWeek— grant your app read access to user preferences, so your app can adjust how it displays information. You can also register a BroadcastReceiver on ACTION_LOCALE_CHANGED to handle locale configuration changes when regional preferences change.

To find these settings, open the Settings app and navigate to System > Languages & input > Regional preferences.

Regional preferences screen in Android system settings.
Temperature options for regional preferences in Android system settings.

無障礙功能

非線性字型縮放至 200%

自 Android 14 起,系統將支援高達 200% 的字型縮放功能,為低視能使用者提供符合無障礙網頁內容規範 (WCAG)的額外無障礙選項。

為避免畫面上的大型文字元素縮放過大,系統會套用非線性縮放曲線。套用此縮放策略後,大型文字的縮放比例會和小型文字的縮放比例有所區別。非線性字型縮放有助於保留不同大小元素之間的比例階層,同時減少高度線性文字縮放的問題 (例如文字遭到截斷,或因顯示大小過大而難以閱讀的文字)。

使用非線性字型縮放測試應用程式

請在裝置的無障礙設定中啟用字型大小上限,以便測試您的應用程式。

如果您已使用縮放像素 (sp) 單位來定義文字大小,這些額外選項和縮放改善功能會自動套用至應用程式中的文字。不過,您仍應執行 UI 測試,並將字型大小上限設為啟用 (200%),以確保應用程式能正確套用字型大小,而且能在不影響可用性的情況下容納較大的字型大小。

如要啟用 200% 的字型大小,請按照下列步驟進行:

  1. 開啟「設定」應用程式,然後依序前往「無障礙中心」>「顯示大小與文字」
  2. 在「字型大小」選項中,輕觸加號 (+) 圖示,直到達字型大小上限為止,如本節隨附的圖片所示。

使用經過調整像素 (sp) 的單位處理文字大小

請記得一律以 sp 單位指定文字大小。如果您的應用程式使用 sp 單位,Android 可套用使用者偏好的文字大小,並適當縮放。

請勿使用 sp 單位做為邊框間距,或是假定檢視畫面高度,並假設有隱性邊框間距:使用非線性字型縮放 sp 尺寸可能不是比例,因此 4sp + 20sp 不一定會等於 24sp。

轉換經過調整像素 (sp) 的單位

使用 TypedValue.applyDimension() 將 sp 單位轉換為像素,並使用 TypedValue.deriveDimension() 將像素轉換為 sp。這些方法會自動套用適當的非線性縮放曲線。

避免使用硬式編碼方程式使用 Configuration.fontScaleDisplayMetrics.scaledDensity。由於字型縮放功能為非線性方式,因此 scaledDensity 欄位已變得不準確。fontScale 欄位應僅用於提供資訊,因為字型不再需要以單一純量值縮放字型。

使用 sp 單位做為 lineHeight

請一律使用 sp 單位 (而非 dp) 定義 android:lineHeight,讓行高會隨著文字縮放。否則,如果文字是 sp,但 lineHeight 是以 dp 或 px 為單位,則無法縮放,看起來會遭到破壞。TextView 會自動修正 lineHeight,以便保留預期的比例,但前提是 textSizelineHeight 都已在 sp 單位中定義。

相機與媒體

圖像專用 Ultra HDR

An illustration of Standard Dynamic Range (SDR) versus High Dynamic Range (HDR) image quality.

Android 14 adds support for High Dynamic Range (HDR) images that retain more of the information from the sensor when taking a photo, which enables vibrant colors and greater contrast. Android uses the Ultra HDR format, which is fully backward compatible with JPEG images, allowing apps to seamlessly interoperate with HDR images, displaying them in Standard Dynamic Range (SDR) as needed.

Rendering these images in the UI in HDR is done automatically by the framework when your app opts in to using HDR UI for its Activity Window, either through a manifest entry or at runtime by calling Window.setColorMode(). You can also capture compressed Ultra HDR still images on supported devices. With more colors recovered from the sensor, editing in post can be more flexible. The Gainmap associated with Ultra HDR images can be used to render them using OpenGL or Vulkan.

相機擴充功能提供縮放、對焦、貼文檢視畫面和其他功能

Android 14 upgrades and improves camera extensions, allowing apps to handle longer processing times, which enables improved images using compute-intensive algorithms like low-light photography on supported devices. These features give users an even more robust experience when using camera extension capabilities. Examples of these improvements include:

感應器縮放功能

CameraCharacteristics 中的 REQUEST_AVAILABLE_CAPABILITIES_STREAM_USE_CASE 包含 SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW 時,應用程式可以使用進階感應器功能,為裁剪的 RAW 串流提供與整個視野相同的像素。只要將 CaptureRequest 搭配串流用途設為 CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW 的 RAW 目標即可。透過實作要求覆寫控制項,新版相機可讓使用者在設定其他相機控制項之前,提供縮放控制項。

無損 USB 音訊

Android 14 gains support for lossless audio formats for audiophile-level experiences over USB wired headsets. You can query a USB device for its preferred mixer attributes, register a listener for changes in preferred mixer attributes, and configure mixer attributes using the AudioMixerAttributes class. This class represents the format, such as channel mask, sample rate, and behavior of the audio mixer. The class allows for audio to be sent directly, without mixing, volume adjustment, or processing effects.

開發人員工作效率和工具

Credential Manager

Android 14 將 Credential Manager 新增為平台 API,並透過 Jetpack 程式庫使用 Google Play 服務,支援 Android 4.4 (API 級別 19) 裝置。Credential Manager 的目標是利用 API 擷取及儲存使用者設定憑證提供者的憑證,讓使用者輕鬆登入。Credential Manager 可在單一 API 中支援多種登入方式,包括使用者名稱/密碼、密碼金鑰,以及聯合登入解決方案 (例如使用 Google 帳戶登入)。

密碼金鑰有許多優點。舉例來說,密碼金鑰是以業界標準建構而成,適用於不同的作業系統和瀏覽器生態系統,也適用於網站和應用程式。

詳情請參閱 Credential Manager 和密碼金鑰說明文件Credential Manager 和密碼金鑰的網誌文章

Health Connect

Health Connect 是裝置端的存放區,存放使用者健康與健身資料。可讓使用者在喜愛的應用程式之間共用資料,並集中控管要與這些應用程式分享哪些資料。

在搭載 Android 14 之前版本的裝置上,您可以在 Google Play 商店中以應用程式形式下載 Health Connect。從 Android 14 開始,Health Connect 是平台的一部分,而且不需另外下載,即可透過 Google Play 系統更新接收更新。如此一來,Health Connect 就可以經常更新,而應用程式必須有搭載 Android 14 以上版本的裝置提供 Health Connect。使用者可透過裝置的「設定」存取 Health Connect,並將隱私權控制項整合至系統設定。

使用者不必另外下載應用程式,就能在搭載 Android 14 以上版本的裝置上開始使用 Health Connect。
使用者可以透過系統設定,控管哪些應用程式可存取其健康與健身資料。

Health Connect 提供 Android 14 的幾項新功能 (例如運動路線),可讓使用者分享健身路線,並透過地圖查看路線。路線是指在一段時間內儲存的位置清單,應用程式可以在運動時段中插入路徑並結合。為確保使用者能完全控管這類機密資料,使用者必須允許與其他應用程式共用個別路徑。

詳情請參閱 Health Connection 說明文件和「Android Health 有哪些新功能」網誌文章。

OpenJDK 17 更新

Android 14 continues the work of refreshing Android's core libraries to align with the features in the latest OpenJDK LTS releases, including both library updates and Java 17 language support for app and platform developers.

The following features and improvements are included:

  • Updated approximately 300 java.base classes to Java 17 support.
  • Text Blocks, which introduce multi-line string literals to the Java programming language.
  • Pattern Matching for instanceof, which allows an object to be treated as having a specific type in an instanceof without any additional variables.
  • Sealed classes, which allow you restrict which classes and interfaces can extend or implement them.

Thanks to Google Play system updates (Project Mainline), over 600 million devices are enabled to receive the latest Android Runtime (ART) updates that include these changes. This is part of our commitment to give apps a more consistent, secure environment across devices, and to deliver new features and capabilities to users independent of platform releases.

Java and OpenJDK are trademarks or registered trademarks of Oracle and/or its affiliates.

應用程式商店改善項目

Android 14 introduces several PackageInstaller APIs that allow app stores to improve their user experience.

Request install approval before downloading

Installing or updating an app might require user approval. For example, when an installer making use of the REQUEST_INSTALL_PACKAGES permission attempts to install a new app. In prior Android versions, app stores can only request user approval after APKs are written to the install session and the session is committed.

Starting with Android 14, the requestUserPreapproval() method lets installers request user approval before committing the install session. This improvement lets an app store defer downloading any APKs until after the installation has been approved by the user. Furthermore, once a user has approved installation, the app store can download and install the app in the background without interrupting the user.

Claim responsibility for future updates

The setRequestUpdateOwnership() method allows an installer to indicate to the system that it intends to be responsible for future updates to an app it is installing. This capability enables update ownership enforcement, meaning that only the update owner is permitted to install automatic updates to the app. Update ownership enforcement helps to ensure that users receive updates only from the expected app store.

Any other installer, including those making use of the INSTALL_PACKAGES permission, must receive explicit user approval in order to install an update. If a user decides to proceed with an update from another source, update ownership is lost.

Update apps at less-disruptive times

App stores typically want to avoid updating an app that is actively in use because this leads to the app's running processes being killed, which potentially interrupts what the user was doing.

Starting with Android 14, the InstallConstraints API gives installers a way to ensure that their app updates happen at an opportune moment. For example, an app store can call the commitSessionAfterInstallConstraintsAreMet() method to make sure that an update is only committed when the user is no longer interacting with the app in question.

Seamlessly install optional splits

With split APKs, features of an app can be delivered in separate APK files, rather than as a monolithic APK. Split APKs allow app stores to optimize the delivery of different app components. For example, app stores might optimize based on the properties of the target device. The PackageInstaller API has supported splits since its introduction in API level 22.

In Android 14, the setDontKillApp() method allows an installer to indicate that the app's running processes shouldn't be killed when new splits are installed. App stores can use this feature to seamlessly install new features of an app while the user is using the app.

應用程式中繼資料套件

從 Android 14 開始,Android 套件安裝程式可讓您指定應用程式中繼資料 (例如資料安全性做法),以加入 Google Play 等應用程式商店頁面。

在使用者擷取裝置螢幕畫面時偵測

為建立更標準化的螢幕截圖偵測體驗,Android 14 推出了具隱私保護功能的螢幕截圖偵測 API。此 API 可讓應用程式依個別活動登錄回呼。當使用者在具備瀏覽權限的活動中拍攝螢幕截圖時,系統會叫用這些回呼,並傳送通知給使用者。

使用者體驗

Sharesheet 自訂動作與改善排名

Android 14 會更新系統 Sharesheet,以支援自訂應用程式動作,使用者也能取得更豐富的預覽結果。

新增自訂動作

在 Android 14 中,應用程式可將自訂動作新增至其叫用的系統 Sharesheet

Sharesheet 上自訂動作的螢幕截圖。

改善直接分享目標的排名

Android 14 會使用更多應用程式信號來判斷直接分享目標的排名,以便為使用者提供更實用的結果。如要提供最實用的排名信號,請按照提高直接分享目標的排名指南操作。通訊應用程式也可以針對傳出和傳入訊息回報捷徑使用情形

Sharesheet 中的直接共用列,如 1 所示

支援預測返回功能的內建和自訂動畫

影片:預測返回動畫

Android 13 推出了在開發人員選項背後顯示「預測返回主畫面」動畫的功能。只要使用支援的應用程式,並啟用開發人員選項,當您執行滑動返回的操作時,系統就會顯示動畫,指出返回手勢可讓應用程式結束並返回主畫面。

Android 14 內含多項改善項目,並提供有關預測返回手勢的全新指南:

在這個 Android 14 預先發布版本中,所有預測返回相關功能都保留在開發人員選項後方。請參閱開發人員指南,瞭解如何讓應用程式改用預測返回功能,以及如何建立自訂的應用程式內轉場效果

大螢幕裝置製造商個別應用程式覆寫值

裝置製造商可以透過個別應用程式覆寫值,變更大螢幕裝置上的應用程式行為。舉例來說,即使應用程式資訊清單中已設定 resizeableActivity="false"FORCE_RESIZE_APP 覆寫值仍會指示系統根據螢幕尺寸調整應用程式大小 (避免使用大小相容性模式)。

覆寫功能旨在改善大螢幕的使用者體驗。

您可以利用新的資訊清單屬性,為應用程式停用部分裝置製造商覆寫值。

大螢幕使用者個別應用程式覆寫值

個別應用程式覆寫值會變更應用程式在大螢幕裝置上的行為。舉例來說,無論應用程式設定為何,OVERRIDE_MIN_ASPECT_RATIO_LARGE 裝置製造商覆寫值都會將應用程式顯示比例設為 16:9。

Android 14 QPR1 可讓使用者在大螢幕裝置上提供新的設定選單,藉此套用個別應用程式的覆寫值。

分享應用程式畫面

應用程式分享螢幕畫面功能可讓使用者在錄製螢幕畫面時,分享應用程式視窗,而非整個裝置螢幕畫面。

應用程式分享螢幕畫面時,狀態列、導覽列、通知和其他系統 UI 元素都不會在共用螢幕上排除。系統只會分享所選應用程式的內容。

應用程式分享螢幕畫面功能可讓使用者執行多個應用程式,但只分享單一應用程式的內容,藉此提高工作效率和隱私權。

Pixel 8 Pro 上的 Gboard 支援 LLM 智慧回覆功能

On Pixel 8 Pro devices with the December Feature Drop, developers can try out higher-quality smart replies in Gboard powered by on-device Large Language Models (LLMs) running on Google Tensor.

This feature is available as a limited preview for US English in WhatsApp, Line, and KakaoTalk. It requires using a Pixel 8 Pro device with Gboard as your keyboard.

To try it out, first enable the feature in Settings > Developer Options > AiCore Settings > Enable Aicore Persistent.

Next, open a conversation in a supported app to see LLM-powered Smart Reply in Gboard's suggestion strip in response to incoming messages.

Gboard utilizes on-device LLMs to provide higher-quality smart replies.

圖像

路徑可供查詢及內插

Android's Path API is a powerful and flexible mechanism for creating and rendering vector graphics, with the ability to stroke or fill a path, construct a path from line segments or quadratic or cubic curves, perform boolean operations to get even more complex shapes, or all of these simultaneously. One limitation is the ability to find out what is actually in a Path object; the internals of the object are opaque to callers after creation.

To create a Path, you call methods such as moveTo(), lineTo(), and cubicTo() to add path segments. But there has been no way to ask that path what the segments are, so you must retain that information at creation time.

Starting in Android 14, you can query paths to find out what's inside of them. First, you need to get a PathIterator object using the Path.getPathIterator API:

Kotlin

val path = Path().apply {
    moveTo(1.0f, 1.0f)
    lineTo(2.0f, 2.0f)
    close()
}
val pathIterator = path.pathIterator

Java

Path path = new Path();
path.moveTo(1.0F, 1.0F);
path.lineTo(2.0F, 2.0F);
path.close();
PathIterator pathIterator = path.getPathIterator();

Next, you can call PathIterator to iterate through the segments one by one, retrieving all of the necessary data for each segment. This example uses PathIterator.Segment objects, which packages up the data for you:

Kotlin

for (segment in pathIterator) {
    println("segment: ${segment.verb}, ${segment.points}")
}

Java

while (pathIterator.hasNext()) {
    PathIterator.Segment segment = pathIterator.next();
    Log.i(LOG_TAG, "segment: " + segment.getVerb() + ", " + segment.getPoints());
}

PathIterator also has a non-allocating version of next() where you can pass in a buffer to hold the point data.

One of the important use cases of querying Path data is interpolation. For example, you might want to animate (or morph) between two different paths. To further simplify that use case, Android 14 also includes the interpolate() method on Path. Assuming the two paths have the same internal structure, the interpolate() method creates a new Path with that interpolated result. This example returns a path whose shape is halfway (a linear interpolation of .5) between path and otherPath:

Kotlin

val interpolatedResult = Path()
if (path.isInterpolatable(otherPath)) {
    path.interpolate(otherPath, .5f, interpolatedResult)
}

Java

Path interpolatedResult = new Path();
if (path.isInterpolatable(otherPath)) {
    path.interpolate(otherPath, 0.5F, interpolatedResult);
}

The Jetpack graphics-path library enables similar APIs for earlier versions of Android as well.

使用頂點和片段著色器的自訂網格

Android has long supported drawing triangle meshes with custom shading, but the input mesh format has been limited to a few predefined attribute combinations. Android 14 adds support for custom meshes, which can be defined as triangles or triangle strips, and can, optionally, be indexed. These meshes are specified with custom attributes, vertex strides, varying, and vertex and fragment shaders written in AGSL.

The vertex shader defines the varyings, such as position and color, while the fragment shader can optionally define the color for the pixel, typically by using the varyings created by the vertex shader. If color is provided by the fragment shader, it is then blended with the current Paint color using the blend mode selected when drawing the mesh. Uniforms can be passed into the fragment and vertex shaders for additional flexibility.

Canvas 的硬體緩衝區轉譯器

為協助使用 Android Canvas API 以硬體加速功能在 HardwareBuffer 中繪圖,Android 14 推出了 HardwareBufferRenderer。如果您的用途涉及透過 SurfaceControl 與系統合成器通訊,以進行低延遲繪製,這個 API 特別實用。