功能與 API 總覽

Android 14 為開發人員推出了強大的新功能和 API。以下資訊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 差異比較表。如要進一步瞭解新增的 API，請參閱 Android API 參考資料。如果是 Android 14，請找出 API 級別 34 中新增的 API。如要瞭解平台變更可能對應用程式造成的影響，請務必查看指定 Android 14 的應用程式和所有應用程式 的 Android 14 行為變更。

國際化

個別應用程式語言偏好

Android 14 進一步延伸 Android 13 (API 級別 33) 所推出的個別應用程式語言功能，並新增多項功能：

  • 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為該檔案新增參照，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，以決定要納入 LocaleConfig 檔案的語言代碼。

  • 應用程式 localeConfig 的動態更新：請使用 法LocaleManager 中的 setOverrideLocaleConfig() 和 getOverrideLocaleConfig() 方法，以動態方式更新應用程式在裝置的系統設定中的支援語言清單。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() 方法檢查當前應用程式的語言，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象或目標的性別，而有不同變化形式的文法類別語言。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，可能會對其表現及態度產生負面影響。相較之下，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。

To help you build a user-centric UI for gendered languages, Android 14 introduces the Grammatical Inflection API, which lets you add support for grammatical gender without refactoring your app.

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.

無障礙設定

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.fontScale 或 DisplayMetrics.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 textSize 和 lineHeight 都已在 sp 單位中定義。

相機和媒體

圖片的 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.

相機擴充功能中的縮放、聚焦、後視等功能

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:

感應器內縮放

當 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，透過 CaptureRequest 和 RAW 目標 (其串流用途已設為 CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW)，為經裁剪的 RAW 串流提供與全景視野相同的像素。透過實作要求覆寫控制項，更新後的相機可在其他相機控制項準備就緒前，提供縮放控制選項。

無損 USB 音訊

Android 14 支援無損音訊格式，可透過 USB 有線耳機提供頂級音響體驗。您可以查詢 USB 裝置的偏好混合器屬性、註冊偏好混合器屬性變更的事件監聽器，以及使用 AudioMixerAttributes 類別設定混合器屬性。這個類別代表音訊調音器的格式，例如通道遮罩、取樣率和行為。這個類別可讓您直接傳送音訊，不必進行混合、音量調整或處理效果。

開發人員工作效率和工具

Credential Manager

Android 14 會新增 Credential Manager 做為平台 API，並透過使用 Google Play 服務的 Jetpack 程式庫，進一步支援 Android 4.4 (API 級別 19) 裝置。Credential Manager 的目標是透過 API 協助使用者輕鬆登入，這些 API 會透過使用者設定的憑證提供者擷取及儲存憑證。Credential Manager 可在單一 API 中支援多種登入方式，包括使用者名稱和密碼、密碼金鑰，以及聯合登入解決方案 (例如使用 Google 帳戶登入)。

密碼金鑰具有許多優點，舉例來說，密碼金鑰採用業界標準，可在不同作業系統和瀏覽器環境中運作，也能與網站和應用程式搭配使用。

如需更多資訊，請參閱 Credential Manager 和密碼金鑰說明文件，以及Credential Manager 和密碼金鑰相關網誌文章。

Health Connect

Health Connect is an on-device repository for user health and fitness data. It allows users to share data between their favorite apps, with a single place to control what data they want to share with these apps.

On devices running Android versions prior to Android 14, Health Connect is available to download as an app on the Google Play store. Starting with Android 14, Health Connect is part of the platform and receives updates through Google Play system updates without requiring a separate download. With this, Health Connect can be updated frequently, and your apps can rely on Health Connect being available on devices running Android 14 or higher. Users can access Health Connect from the Settings in their device, with privacy controls integrated into the system settings.

Users can get started using Health Connect without a separate app download on devices running Android 14 or higher.
Users can control which apps have access to their health and fitness data through system settings.

Health Connect includes several new features in Android 14, such as exercise routes, allowing users to share a route of their workout which can be visualized on a map. A route is defined as a list of locations saved within a window of time, and your app can insert routes into exercise sessions, tying them together. To ensure that users have complete control over this sensitive data, users must allow sharing individual routes with other apps.

For more information, see the Health Connection documentation and the blogpost on What's new in Android Health.

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

Starting in Android 14, the Android package installer lets you specify app metadata, such as data safety practices, to include on app store pages such as Google Play.

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 updates the system sharesheet to support custom app actions and more informative preview results for users.

Add custom actions

With Android 14, your app can add custom actions to the system sharesheet it invokes.

Screenshot of custom actions on the sharesheet.

Improve ranking of Direct Share targets

Android 14 uses more signals from apps to determine the ranking of the direct share targets to provide more helpful results for the user. To provide the most useful signal for ranking, follow the guidance for improving rankings of your Direct Share targets. Communication apps can also report shortcut usage for outgoing and incoming messages.

Direct Share row in the sharesheet, as shown by 1

支援預測返回功能的內建和自訂動畫

Video: Predictive back animations

Android 13 introduced the predictive back-to-home animation behind a developer option. When used in a supported app with the developer option enabled, swiping back shows an animation indicating that the back gesture exits the app back to the home screen.

Android 14 includes multiple improvements and new guidance for Predictive Back:

With this Android 14 preview release, all features of Predictive Back remain behind a developer option. See the developer guide to migrate your app to predictive back, as well as the developer guide to creating custom in-app transitions.

大螢幕裝置製造商個別應用程式覆寫值

Per-app overrides enable device manufacturers to change the behavior of apps on large screen devices. For example, the FORCE_RESIZE_APP override instructs the system to resize the app to fit display dimensions (avoiding size compatibility mode) even if resizeableActivity="false" is set in the app manifest.

Overrides are intended to improve the user experience on large screens.

New manifest properties enable you to disable some device manufacturer overrides for your app.

大螢幕使用者個別應用程式覆寫值

Per-app overrides change the behavior of apps on large screen devices. For example, the OVERRIDE_MIN_ASPECT_RATIO_LARGE device manufacturer override sets the app aspect ratio to 16:9 regardless of the app's configuration.

Android 14 QPR1 enables users to apply per‑app overrides by means of a new settings menu on large screen devices.

應用程式分享螢幕畫面

App screen sharing enables users to share an app window instead of the entire device screen during screen content recording.

With app screen sharing, the status bar, navigation bar, notifications, and other system UI elements are excluded from the shared display. Only the content of the selected app is shared.

App screen sharing improves productivity and privacy by enabling users to run multiple apps but limit content sharing to a single app.

在 Pixel 8 Pro 上使用 LLM 技術支援的 Gboard 智慧回覆功能

在搭載 12 月功能更新的 Pixel 8 Pro 裝置上，開發人員可以試用 Gboard 中採用 Google Tensor 晶片的大型語言模型 (LLM) 所提供的更高品質智慧回覆功能。

這項功能目前僅在 WhatsApp、Line 和 KakaoTalk 提供美式英文的限量預覽版。你必須使用 Pixel 8 Pro 裝置，並將 Gboard 做為鍵盤。

如要試用這項功能，請先依序前往「設定」>「開發人員選項」>「AI Core 設定」>「啟用 Aicore 持續性」。

接著，在支援的應用程式中開啟對話，即可在 Gboard 的建議列中看到 LLM 支援的智慧回覆功能，以回覆傳入的訊息。

Gboard 會使用裝置端 LLM 提供更高品質的智慧回覆。

圖形

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 的 Canvas API 以硬體加速繪製至 HardwareBuffer，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，以便繪製低延遲畫面，這個 API 就特別實用。