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
用户可通过地区偏好设置对温度单位、一周的第一天和编号系统进行个性化设置。居住在美国的欧洲用户可能更希望使用摄氏度,而不是华氏度,并且希望应用将星期一视为一周的开始,而不是像美国那样默认从星期日开始。
新 Android 设置菜单包含这些偏好设置,使用户能够在一个位置集中发现这些应用更改偏好设置。这些偏好设置在备份和恢复设备后也会保持不变。多个 API 和 intent(例如 getTemperatureUnit
和 getFirstDayOfWeek
)会为您的应用授予读取权限来访问用户偏好设置,因此您的应用可以调整其显示信息的方式。您还可以在 ACTION_LOCALE_CHANGED
上注册 BroadcastReceiver
,以便在地区偏好设置发生更改时处理语言区域配置更改。
如需找到这些设置,请打开“设置”应用,然后依次前往系统 > 语言和输入法 > 地区偏好设置。
![](https://developer.android.google.cn/static/about/versions/14/images/regional-preferences.png?authuser=8&hl=hu)
![](https://developer.android.google.cn/static/about/versions/14/images/regional-preferences-temperature.png?authuser=8&hl=hu)
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=8&hl=hu)
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=8&hl=hu)
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 升级并改进了相机扩展,使应用能够处理更长的处理时间,从而支持在受支持的设备上使用弱光摄影等计算密集型算法来改进图像。在使用相机扩展功能时,这些功能可让用户获得更可靠的体验。这些改进的示例包括:
- 动态静态拍摄的处理延迟时间估算值会根据当前的场景和环境条件提供更准确的静态拍摄延迟时间估算值。调用
CameraExtensionSession.getRealtimeStillCaptureLatency()
以获取具有两种延迟时间估算方法的StillCaptureLatency
对象。getCaptureLatency()
方法返回onCaptureStarted
和onCaptureProcessStarted()
之间的估计延迟时间,getProcessingLatency()
方法返回onCaptureProcessStarted()
与最终处理后的帧可用之间的估计延迟时间。 - 支持拍摄进度回调,以便应用可以显示长时间运行的静态拍摄处理操作的当前进度。您可以使用
CameraExtensionCharacteristics.isCaptureProcessProgressAvailable
检查此功能是否可用,如果可用,请实现onCaptureProcessProgressed()
回调,该回调会将进度(从 0 到 100)以参数形式传入。 特定于扩展程序的元数据,例如
CaptureRequest.EXTENSION_STRENGTH
,用于调整扩展效果的程度,例如使用EXTENSION_BOKEH
时的背景模糊处理程度。相机扩展中的静态拍摄功能(用于静态拍摄)的后视图功能,相比最终图片,提供处理较少的图片。如果扩展程序延长了处理延迟时间,则可以提供浏览后图片作为占位符来改善用户体验,之后可针对最终图片关闭该功能。您可以通过
CameraExtensionCharacteristics.isPostviewAvailable
检查此功能是否可用。然后,您可以将OutputConfiguration
传递给ExtensionSessionConfiguration.setPostviewOutputConfiguration
。支持
SurfaceView
,可实现更优化、更节能的预览渲染路径。支持在使用扩展程序期间点按即可对焦和缩放。
传感器内缩放
当 CameraCharacteristics
中的 REQUEST_AVAILABLE_CAPABILITIES_STREAM_USE_CASE
包含 SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW
时,您的应用可以使用高级传感器功能,通过使用 CaptureRequest
以及数据流用例设置为 CameraMetadata.SCALER_AVAILABLE_STREAM_USE_CASES_CROPPED_RAW
的 RAW 目标,为剪裁后的 RAW 数据流提供与完整视野相同的像素。通过实现请求替换控件,更新后的摄像头让用户可在其他摄像头控件准备就绪之前实现缩放控制。
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 添加了 Credential Manager 作为平台 API,并通过使用 Google Play 服务的 Jetpack 库为 Android 4.4(API 级别 19)设备提供了额外的支持。凭据管理器旨在使用 API 通过用户配置的凭据提供程序检索和存储凭据,让用户更轻松地登录。凭据管理器在一个 API 中支持多种登录方法,包括用户名和密码、通行密钥和联合登录解决方案(如“使用 Google 账号登录”)。
通行密钥具有许多优势。例如,通行密钥基于业界标准构建,可在不同的操作系统和浏览器生态系统中使用,还可用于网站和应用。
如需了解详情,请参阅凭据管理器和通行密钥文档以及关于 Credential Manager 和通行密钥的博文。
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=8&hl=hu)
![](https://developer.android.google.cn/static/images/about/versions/14/health-connect-permissions.png?authuser=8&hl=hu)
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 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.
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
为了打造更加标准化的屏幕截图检测体验,Android 14 引入了可保护隐私的屏幕截图检测 API。借助此 API,应用可以按 activity 注册回调。如果用户在该 activity 可见时截取屏幕截图,系统会调用这些回调并通知用户。
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=8&hl=hu)
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=8&hl=hu)
支持内置和自定义预测性返回动画
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:
- You can set
android:enableOnBackInvokedCallback=true
to opt in to predictive back system animations per-Activity instead of for the entire app. - We've added new system animations to accompany the back-to-home animation from Android 13. The new system animations are cross-activity and cross-task, which you get automatically after migrating to Predictive Back.
- We've added new Material Component animations for Bottom sheets, Side sheets, and Search.
- We've created design guidance for creating custom in-app animations and transitions.
- We've added new APIs to support custom in-app transition animations:
handleOnBackStarted
,handleOnBackProgressed
,handleOnBackCancelled
in
OnBackPressedCallback
onBackStarted
,onBackProgressed
,onBackCancelled
in
OnBackAnimationCallback
- Use
overrideActivityTransition
instead ofoverridePendingTransition
for transitions that respond as the user swipes 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
借助按应用替换项,设备制造商可以在大屏设备上更改应用的行为。例如,FORCE_RESIZE_APP
替换项指示系统调整应用大小以适应显示屏尺寸(避免尺寸兼容模式),即使在应用清单中设置了 resizeableActivity="false"
也是如此。
替换项旨在改善大屏设备上的用户体验。
借助新的清单属性,您可以为应用停用某些设备制造商替换项。
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
为协助使用 Android 的 Canvas
API 通过硬件加速在 HardwareBuffer
中进行绘制,Android 14 引入了 HardwareBufferRenderer
。当您的用例涉及通过 SurfaceControl
与系统合成器进行通信以实现低延迟绘制时,此 API 特别有用。