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 expands on the per-app language features that were introduced in Android 13 (API level 33) with these additional capabilities:
Automatically generate an app's
localeConfig
: Starting with Android Studio Giraffe Canary 7 and AGP 8.1.0-alpha07, you can configure your app to support per-app language preferences automatically. Based on your project resources, the Android Gradle plugin generates theLocaleConfig
file and adds a reference to it in the final manifest file, so you no longer have to create or update the file manually. AGP uses the resources in theres
folders of your app modules and any library module dependencies to determine the locales to include in theLocaleConfig
file.Dynamic updates for an app's
localeConfig
: Use thesetOverrideLocaleConfig()
andgetOverrideLocaleConfig()
methods inLocaleManager
to dynamically update your app's list of supported languages in the device's system settings. Use this flexibility to customize the list of supported languages per region, run A/B experiments, or provide an updated list of locales if your app utilizes server-side pushes for localization.App language visibility for input method editors (IMEs): IMEs can utilize the
getApplicationLocales()
method to check the language of the current app and match the IME language to that language.
Grammatical Inflection API
有 30 亿人在使用区分性别的语言,此类语言的语法类别(例如名词、动词、形容词和介词)会根据您交谈所涉及的人或物的性别而变化。传统上,许多区分性别的语言使用阳性语法性别作为默认或通用性别。
以错误的语法性别来称呼用户,例如以阳性语法性别来称呼女性,可能会对她们的表现和态度产生负面影响。相比之下,界面语言如果能正确反映用户的语法性别,就可以提高用户互动度,并提供更个性化、更自然的用户体验。
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.
![](https://developer.android.google.cn/static/about/versions/14/images/regional-preferences.png?authuser=5&hl=da)
![](https://developer.android.google.cn/static/about/versions/14/images/regional-preferences-temperature.png?authuser=5&hl=da)
无障碍功能
非线性字体放大至 200%
Starting in Android 14, the system supports font scaling up to 200%, providing low-vision users with additional accessibility options that align with Web Content Accessibility Guidelines (WCAG).
To prevent large text elements on screen from scaling too large, the system applies a nonlinear scaling curve. This scaling strategy means that large text doesn't scale at the same rate as smaller text. Nonlinear font scaling helps preserve the proportional hierarchy between elements of different sizes while mitigating issues with linear text scaling at high degrees (such as text being cut off or text that becomes harder to read due to an extremely large display sizes).
Test your app with nonlinear font scaling
![](https://developer.android.google.cn/static/images/about/versions/14/accessibility-font-options.png?authuser=5&hl=da)
If you already use scaled pixels (sp) units to define text sizing, then these additional options and scaling improvements are applied automatically to the text in your app. However, you should still perform UI testing with the maximum font size enabled (200%) to ensure that your app applies the font sizes correctly and can accommodate larger font sizes without impacting usability.
To enable 200% font size, follow these steps:
- Open the Settings app and navigate to Accessibility > Display size and text.
- For the Font size option, tap the plus (+) icon until the maximum font size setting is enabled, as shown in the image that accompanies this section.
Use scaled pixel (sp) units for text-sizes
Remember to always specify text sizes in sp units. When your app uses sp units, Android can apply the user's preferred text size and scale it appropriately.
Don't use sp units for padding or define view heights assuming implicit padding: with nonlinear font scaling sp dimensions might not be proportional, so 4sp + 20sp might not equal 24sp.
Convert scaled pixel (sp) units
Use TypedValue.applyDimension()
to convert from sp units
to pixels, and use TypedValue.deriveDimension()
to
convert pixels to sp. These methods apply the appropriate nonlinear scaling
curve automatically.
Avoid hardcoding equations using
Configuration.fontScale
or
DisplayMetrics.scaledDensity
. Because font scaling is
nonlinear, the scaledDensity
field is no longer accurate. The fontScale
field should be used for informational purposes only because fonts are no longer
scaled with a single scalar value.
Use sp units for lineHeight
Always define android:lineHeight
using sp units instead
of dp, so the line height scales along with your text. Otherwise, if your text
is sp but your lineHeight
is in dp or px, it doesn't scale and looks cramped.
TextView automatically corrects the lineHeight
so that your intended
proportions are preserved, but only if both textSize
and lineHeight
are
defined in sp units.
摄像头和媒体
图片 Ultra HDR
![](https://developer.android.google.cn/static/images/about/versions/14/SDR-HDR-compare.png?authuser=5&hl=da)
Android 14 增加了对高动态范围 (HDR) 图片的支持,此类图片可在拍照时保留来自传感器的更多信息,从而实现鲜艳的色彩和更高的对比度。Android 采用 Ultra HDR 格式,这种格式可完全向后兼容 JPEG 图片,允许应用与 HDR 图片无缝互操作,从而根据需要以标准动态范围 (SDR) 显示图片。
当您的应用为其 Activity 窗口选择使用 HDR 界面(通过清单条目或在运行时通过调用 Window.setColorMode()
)时,框架会自动在 HDR 界面中呈现这些图片。您还可以在支持的设备上拍摄压缩的 Ultra HDR 静态图片。从传感器中恢复的颜色越多,博文中的编辑效果就越灵活。与 Ultra HDR 图片关联的 Gainmap
可用于使用 OpenGL 或 Vulkan 渲染这些图片。
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:
- Dynamic still capture processing latency estimation provides much more
accurate still capture latency estimates based on the current scene and
environment conditions. Call
CameraExtensionSession.getRealtimeStillCaptureLatency()
to get aStillCaptureLatency
object that has two latency estimation methods. ThegetCaptureLatency()
method returns the estimated latency betweenonCaptureStarted
andonCaptureProcessStarted()
, and thegetProcessingLatency()
method returns the estimated latency betweenonCaptureProcessStarted()
and the final processed frame being available. - Support for capture progress callbacks so that apps can display the current
progress of long-running, still-capture processing operations. You can check
if this feature is available with
CameraExtensionCharacteristics.isCaptureProcessProgressAvailable
, and if it is, you implement theonCaptureProcessProgressed()
callback, which has the progress (from 0 to 100) passed in as a parameter. Extension specific metadata, such as
CaptureRequest.EXTENSION_STRENGTH
for dialing in the amount of an extension effect, such as the amount of background blur withEXTENSION_BOKEH
.Postview Feature for Still Capture in camera extensions, which provides a less-processed image more quickly than the final image. If an extension has increased processing latency, a postview image could be provided as a placeholder to improve UX and switched out later for the final image. You can check if this feature is available with
CameraExtensionCharacteristics.isPostviewAvailable
. Then you can pass anOutputConfiguration
toExtensionSessionConfiguration.setPostviewOutputConfiguration
.Support for
SurfaceView
allowing for a more optimized and power-efficient preview render path.Support for tap to focus and zoom during extension usage.
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 开始支持无损音频格式,通过 USB 有线耳机提供发烧级体验。您可以查询 USB 设备的首选混音器属性,注册监听器以监听首选混音器属性的变化,并使用 AudioMixerAttributes
类配置混音器属性。此类表示格式,例如声道掩码、采样率和混音器行为。该类允许直接发送音频,而不进行混音、音量调整或处理效果。
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.
![](https://developer.android.google.cn/static/images/about/versions/14/health-connect-screen.png?authuser=5&hl=da)
![](https://developer.android.google.cn/static/images/about/versions/14/health-connect-permissions.png?authuser=5&hl=da)
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 将继续更新 Android 的核心库,以与最新 OpenJDK LTS 版本中的功能保持一致,包括适合应用和平台开发者的库更新和 Java 17 语言支持。
其中包含以下功能和改进:
- 将大约 300 个
java.base
类更新为支持 Java 17。 - 文本块 - 为 Java 编程语言引入了多行字符串字面量。
- instanceof 模式匹配:可让对象在
instanceof
中被视为具有特定类型,而无需任何额外的变量。 - 密封类:允许您限制哪些类和接口可以扩展或实现它们。
得益于 Google Play 系统更新 (Project Mainline),6 亿多台设备能够接收包含这些更改的最新 Android 运行时 (ART) 更新。我们致力于为应用提供更加一致、安全的跨设备环境,并为用户提供独立于平台版本的新功能。
Java 和 OpenJDK 是 Oracle 及/或其关联公司的商标或注册商标。
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.
![](https://developer.android.google.cn/static/images/training/sharing/sharesheet_custom_actions.png?authuser=5&hl=da)
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.
![](https://developer.android.google.cn/static/training/sharing/direct-share-targets.png?authuser=5&hl=da)
支持内置和自定义预测性返回动画
Android 13 在开发者选项背后引入了预测性“返回主屏幕”动画。在已启用开发者选项的受支持应用中使用时,滑回手势会显示动画,表明返回手势会使应用退回到主屏幕。
Android 14 包含针对“预测性返回”的多项改进和新指南:
- 您可设置
android:enableOnBackInvokedCallback=true
,以便为每个 activity 选择启用预测性返回系统动画,而不是为整个应用选择启用。 - 我们添加了新的系统动画,以配合 Android 13 中的“返回主屏幕”动画。新的系统动画是跨 activity 和跨任务的,您可在迁移到预测性返回后自动获得该动画。
- 我们为底部动作条、侧边动作条和搜索添加了新的 Material 组件动画。
- 我们制作了有关如何创建自定义应用内动画和转换的设计指南。
- 我们添加了许多新 API 来支持自定义的应用内转换动画:
在此 Android 14 预览版中,所有预测性返回功能都是位于开发者选项背后。请参阅与将您的应用迁移到预测性返回有关的开发者指南,以及与创建自定义应用内转换有关的开发者指南。
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
应用屏幕共享功能让用户能够在录制屏幕内容期间共享应用窗口,而非整个设备屏幕。
使用应用屏幕共享时,状态栏、导航栏、通知和其他系统界面元素会从共享显示屏中排除。系统只会分享所选应用的内容。
应用屏幕共享可让用户运行多个应用,但仅限单个应用共享内容,从而提高效率和隐私性。
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.
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.