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=7&hl=ro)
![](https://developer.android.google.cn/static/about/versions/14/images/regional-preferences-temperature.png?authuser=7&hl=ro)
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
![](https://developer.android.google.cn/static/images/about/versions/14/accessibility-font-options.png?authuser=7&hl=ro)
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:
- 打开“设置”应用,然后依次前往无障碍 > 显示大小和文字。
- 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
![](https://developer.android.google.cn/static/images/about/versions/14/SDR-HDR-compare.png?authuser=7&hl=ro)
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:
- 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 是设备端存储库,用于存储用户健康与健身数据。借助该平台,用户可以在自己喜爱的应用之间共享数据,并集中控制他们想要与这些应用共享的数据。
在搭载 Android 14 之前的 Android 版本的设备上,Health Connect 可作为应用从 Google Play 商店下载。从 Android 14 开始,Health Connect 已成为 Android 平台的一部分,可通过 Google Play 系统更新接收更新,而无需单独下载。这样,Health Connect 就可以经常更新,您的应用可以依赖于搭载 Android 14 或更高版本的设备上的 Health Connect 可用。用户可以通过设备的“设置”页面访问 Health Connect,并将隐私控制集成到系统设置中。
![](https://developer.android.google.cn/static/images/about/versions/14/health-connect-screen.png?authuser=7&hl=ro)
![](https://developer.android.google.cn/static/images/about/versions/14/health-connect-permissions.png?authuser=7&hl=ro)
Health Connect 在 Android 14 中包含多项新功能(例如锻炼路线),让用户可以共享锻炼路线,并在地图上直观呈现这些路线。路线是指一段时间内保存的位置列表,您的应用可以将路线插入锻炼时段,并将其关联起来。为确保用户可以完全控制这些敏感数据,用户必须允许与其他应用共享个别路由。
如需了解详情,请参阅 Health Connection 文档以及 Android Health 的新变化这篇博文。
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
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=7&hl=ro)
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=7&hl=ro)
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
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
按应用替换会更改大屏设备上应用的行为。例如,无论应用的配置如何,OVERRIDE_MIN_ASPECT_RATIO_LARGE
设备制造商替换项都会将应用宽高比设置为 16:9。
Android 14 QPR1 允许用户在大屏设备上通过新的设置菜单应用按应用替换项。
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 的 Path
API 是一种强大且灵活的机制,
创建和渲染矢量图形,能够描边或填充
使用线段、二次曲线或立方曲线构造路径,执行
进行布尔运算,以获取更复杂的形状,
。其中一项限制是,我们不能确定
Path 对象;在创建后,对象的内部信息对调用方是不透明的。
如需创建 Path
,您可以调用如下方法:
moveTo()
、lineTo()
和
cubicTo()
添加路径段。但当前无法
询问该路径有哪些路段,因此,您必须在以下位置保留该信息:
创建时间。
从 Android 14 开始,您可以查询路径以了解其内部内容。首先,您需要使用PathIterator
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();
接下来,您可以调用 PathIterator
来遍历这些细分。
逐个检索每个细分的所有必要数据。本示例
使用 PathIterator.Segment
对象,用于打包数据
:
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
还有 next()
的非分配版本,您可以在该版本中传递
来保存点数据。
查询 Path
数据的一个重要用例是插值。对于
例如,您可能想在两个不同的路径之间添加动画(或变形)。接收者
Android 14 还包含
Path
上的 interpolate()
方法。假设两条路径的
interpolate()
方法会创建一个新的 Path
输出值。此示例返回形状为
介于 path
和 otherPath
之间的一半(线性插值为 0 .5):
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); }
Jetpack graphics-path 库为 Android 早期版本
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。