功能和 API 概览

Android 14 面向开发者引入了强大的功能和 API。下文可帮助您了解适用于您的应用的功能并开始使用相关 API。

如需查看添加、修改和移除的 API 的详细列表，请参阅 API 差异报告。如需详细了解添加的 API，请访问 Android API 参考文档。对于 Android 14，查找在 API 级别 34 中添加的 API。如需了解平台变更可能会在哪些方面影响您的应用，请务必查看以 Android 14 为目标平台的应用和所有应用的 Android 14 行为变更。

国际化

各应用语言偏好设定

Android 14 扩展了 Android 13（API 级别 33）中引入的按应用设定语言功能，并包含以下额外功能：

  • 自动生成应用的 localeConfig：从 Android Studio Giraffe Canary 7 和 AGP 8.1.0-alpha07 开始，您可以将应用配置为自动支持各应用语言偏好设定。Android Gradle 插件会根据您的项目资源生成 LocaleConfig 文件，并在最终清单文件中添加对该文件的引用，这样您就不再需要手动创建或更新该文件。AGP 使用应用模块的 res 文件夹中的资源以及任何库模块依赖项来确定要在 LocaleConfig 文件中添加的语言区域。

  • 动态更新应用的 localeConfig：使用 LocaleManager 方法中的 setOverrideLocaleConfig() 和 getOverrideLocaleConfig() 可以在设备的系统设置中动态更新应用的受支持语言列表。有了这种灵活性，您可以按区域自定义支持的语言列表、运行 A/B 实验，或者如果您的应用通过服务器端推送进行本地化，则可以提供更新后的语言区域列表。

  • 输入法 (IME) 的应用语言可见性：IME 可以利用 getApplicationLocales() 方法查看当前应用的语言，并将 IME 语言与该语言进行匹配。

Grammatical Inflection API

3 billion people speak gendered languages: languages where grammatical categories—such as nouns, verbs, adjectives, and prepositions—inflect according to the gender of people and objects you talk to or about. Traditionally, many gendered languages use masculine grammatical gender as the default or generic gender.

Addressing users in the wrong grammatical gender, such as addressing women in masculine grammatical gender, can negatively impact their performance and attitude. In contrast, a UI with language that correctly reflects the user's grammatical gender can improve user engagement and provide a more personalized and natural-sounding user experience.

为帮助您针对区分性别的语言构建以用户为中心的界面，Android 14 引入了 Grammatical Inflection API，让您无需重构应用便能添加对语法性别的支持。

地区偏好设置

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.

无障碍功能

非线性字体放大至 200%

从 Android 14 开始，系统支持字体放大高达 200%，为弱视用户提供了符合网络内容无障碍指南 (WCAG) 的其他无障碍选项。

为防止屏幕上的大文本元素放大过大，系统会采用非线性放大曲线。这种放大策略意味着大号文本的放大比例不会与较小的文本相同。非线性字体缩放有助于保持不同大小元素之间的比例层次结构，同时缓解高级别线性文本缩放的问题（例如文本被截断或文本因超大显示大小而难以阅读）。

使用非线性字体放大测试应用

在设备的无障碍设置中启用最大字号，以测试应用。

如果您已经使用放大像素 (sp) 单位来定义文本大小，那么这些额外的选项和缩放改进会自动应用于应用中的文本。但是，您仍然应该在启用最大字体大小 (200%) 的情况下执行界面测试，以确保应用正确应用字体大小，并且可以适应更大的字体大小，而不影响易用性。

要启用 200% 字号，请按以下步骤操作：

  1. 打开“设置”应用，然后依次前往无障碍 > 显示大小和文字。
  2. 在字号选项中，点按加号 (+) 图标，直到启用最大字号设置，如本部分随附的图片所示。

针对文本大小使用放大像素 (sp) 单位

请务必始终以 sp 为单位指定文本大小。当应用使用 sp 单位时，Android 可以应用用户的首选文本大小并相应地缩放。

不要为内边距使用 sp 单位，也不假设隐式内边距定义视图高度：使用非线性字体缩放 sp 尺寸可能不成比例，因此 4sp + 20sp 可能不等于 24sp。

转换放大像素 (sp) 单位

使用 TypedValue.applyDimension() 从 sp 单位转换为像素，并使用 TypedValue.deriveDimension() 将像素转换为 sp。这些方法会自动应用适当的非线性缩放曲线。

避免使用 Configuration.fontScale 或 DisplayMetrics.scaledDensity 对方程进行硬编码。由于字体缩放是非线性的，因此 scaledDensity 字段不再准确。fontScale 字段应仅用于提供信息，因为字体不再使用单个标量值进行缩放。

对 lineHeight 使用 sp 单位

始终使用 sp 单位（而非 dp）定义 android:lineHeight，以便行高随文本一起缩放。否则，如果您的文本为 sp，而 lineHeight 以 dp 或 px 为单位，则文本无法缩放且看起来狭窄。TextView 会自动更正 lineHeight 以保留您预期的比例，但前提是以 sp 为单位同时定义 textSize 和 lineHeight。

摄像头和媒体

图片 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.

相机扩展程序中的缩放、对焦、Postview 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:

传感器内缩放

When REQUEST_AVAILABLE_CAPABILITIES_STREAM_USE_CASE in CameraCharacteristics contains SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW, your app can use advanced sensor capabilities to give a cropped RAW stream the same pixels as the full field of view by using a CaptureRequest with a RAW target that has stream use case set to CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW. By implementing the request override controls, the updated camera gives users zoom control even before other camera controls are ready.

无损 USB 音频

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.

开发者工作效率和工具

Credential Manager

Android 14 adds Credential Manager as a platform API, with additional support back to Android 4.4 (API level 19) devices through a Jetpack Library using Google Play services. Credential Manager aims to make sign-in easier for users with APIs that retrieve and store credentials with user-configured credential providers. Credential Manager supports multiple sign-in methods, including username and password, passkeys, and federated sign-in solutions (such as Sign-in with Google) in a single API.

Passkeys provide many advantages. For example, passkeys are built on industry standards, can work across different operating systems and browser ecosystems, and can be used with both websites and apps.

For more information, see the Credential Manager and passkeys documentation and the blogpost about Credential Manager and passkeys.

健康数据共享

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.

针对应用商店的改进

Android 14 引入了多个 PackageInstaller API，可帮助应用商店改善其用户体验。

下载之前请求批准安装

安装或更新应用可能需要用户批准。 例如，当使用 REQUEST_INSTALL_PACKAGES 权限的安装程序尝试安装新应用时。在之前的 Android 版本中，应用商店只有在 APK 写入安装会话且该会话已提交之后才能请求用户批准。

从 Android 14 开始，requestUserPreapproval() 方法可让安装程序在提交安装会话之前请求用户批准。此项改进可让应用商店将任何 APK 的下载操作推迟到用户批准安装之后。此外，用户批准安装后，应用商店可以在后台下载并安装应用，而不会干扰用户。

承担未来更新的责任

通过 setRequestUpdateOwnership() 方法，安装程序可以告知系统它打算负责未来安装的应用更新。此功能可实现更新所有权强制执行，即只有更新所有者才能为应用安装自动更新。更新所有权强制执行有助于确保用户仅从预期的应用商店接收更新。

任何其他安装程序（包括使用 INSTALL_PACKAGES 权限的安装程序）都必须获得用户的明确批准，才能安装更新。如果用户决定继续从其他来源进行更新，更新所有权将会丢失。

在干扰较少的时段更新应用

应用商店通常希望避免更新正在使用的应用，因为这会导致应用正在运行的进程被终止，而这可能会中断用户正在执行的操作。

从 Android 14 开始，InstallConstraints API 让安装程序可以确保其应用更新在适当的时机进行。例如，应用商店可以调用 commitSessionAfterInstallConstraintsAreMet() 方法来确保仅在用户不再与相关应用互动时进行更新。

无缝安装可选拆分

借助拆分 APK，应用的功能可以通过单独的 APK 文件提供，而不是以单体式 APK 的形式提供。借助拆分 APK，应用商店可以优化不同应用组件的提供。例如，应用商店可能会根据目标设备的属性进行优化。自从在 API 级别 22 中引入以来，PackageInstaller API 一直支持拆分。

在 Android 14 中，setDontKillApp() 方法可让安装程序指明在安装新的分块时不应终止应用正在运行的进程。应用商店可以使用此功能，在用户使用应用时无缝安装应用的新功能。

应用元数据软件包

从 Android 14 开始，Android 软件包安装程序可让您指定应用元数据（例如数据安全做法），以将其添加到 Google Play 等应用商店页面。

检测用户何时截取设备屏幕截图

To create a more standardized experience for detecting screenshots, Android 14 introduces a privacy-preserving screenshot detection API. This API lets apps register callbacks on a per-activity basis. These callbacks are invoked, and the user is notified, when the user takes a screenshot while that activity is visible.

用户体验

Sharesheet 自定义操作和经过改进的排名系统

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

支持内置和自定义预测性返回动画

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.

大屏设备制造商按应用替换项

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.

大屏用户按应用替换项

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.

分享应用界面

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.

Pixel 8 Pro 上搭载 LLM 的 Gboard 智能回复

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.

显卡

路径可查询和插值

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.

使用顶点和 fragment 着色器的自定义网格

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.

适用于 Canvas 的硬件缓冲区渲染程序

To assist in using Android's Canvas API to draw with hardware acceleration into a HardwareBuffer, Android 14 introduces HardwareBufferRenderer. This API is particularly useful when your use case involves communication with the system compositor through SurfaceControl for low-latency drawing.