Android AndroidX 简介与迁移

Android

发布日期: 2018-11-06

文章字数: 2.4k

阅读时长: 12 分

AndroidX 简介

AndroidX 是 Android 团队用于在 Jetpack 中开发，测试，打包，版本和发布库的开源项目。

AndroidX 是对原始 Android Support Library的重大改进。与支持库一样，AndroidX 与 Android 操作系统分开提供，并提供跨 Android 版本的向后兼容性。AndroidX 通过提供功能奇偶校验和新库完全取代了支持库。此外，AndroidX 还包括以下功能：

AndroidX 中的所有软件包都以字符串开头，位于一致的命名空间中 androidx。支持库包已映射到相应的 androidx.* 包中。有关所有旧类和构建组件的完整映射到新构件。
与支持库不同，AndroidX 软件包是单独维护和更新的。这些 androidx 包使用从版本 1.0.0 开始的严格语义版本控制。开发者可以单独更新项目中的 AndroidX 库。
所有新的支持库开发都将在 AndroidX 库中进行。这包括维护原始支持库组件和引入新的 Jetpack 组件。

使用 AndroidX

如果要在新项目中使用 AndroidX，则需要一下条件：

使用 Android Studio 3.2 及更高版本
将 compileSdkVersion 设置为 28(Android 9.0)或更高版本
将 gradle-wrapper.properties 文件中的 Gradle 版本改为 4.6或更高版本
在 gradle.properties 文件中将以下两个 Android Gradle 插件标志设置 true：
- android.useAndroidX：设置 true 为时，Android 插件使用相应的 AndroidX 库而不是支持库，默认为 false。
- android.enableJetifier：设置 true 为时，Android 插件会自动迁移现有的第三方库，通过重写其二进制文件来使用 AndroidX，默认为 false。

迁移到 AndroidX

AndroidX 将原始支持库 API 包映射到 androidx 命名空间。只有包和 Maven 组件名称发生了变化; 类、方法和字段名称没有改变。

使用 Android Studio 3.2 及更高版本，您可以通过从菜单栏中选择 Refactor> Migrate to AndroidX 快速迁移现有项目以使用 AndroidX 。

如果您有任何尚未迁移到 AndroidX 名称空间的 Maven 依赖项，那么当您将 gradle.properties 文件中以下两个 Android Gradle 插件标志设置 true，Android Studio 构建系统也会为您迁移这些依赖项：

android.useAndroidX=true
android.enableJetifier=true

要迁移不使用任何需要转换的依赖项的第三方库的现有项目，可以将 android.useAndroidX 标志设置为 true，将 android.enableJetifier 标志设置为 false。

组件映射

下表列出了从旧组件到新组件的当前映射，也可以下载CSV格式映射文件：

旧构建组件	AndroidX 构建组件
android.arch.core:common	androidx.arch.core:core-common:2.0.0-rc01
android.arch.core:core	androidx.arch.core:core:2.0.0-rc01
android.arch.core:core-testing	androidx.arch.core:core-testing:2.0.0-rc01
android.arch.core:runtime	androidx.arch.core:core-runtime:2.0.0-rc01
android.arch.lifecycle:common	androidx.lifecycle:lifecycle-common:2.0.0-rc01
android.arch.lifecycle:common-java8	androidx.lifecycle:lifecycle-common-java8:2.0.0-rc01
android.arch.lifecycle:compiler	androidx.lifecycle:lifecycle-compiler:2.0.0-rc01
android.arch.lifecycle:extensions	androidx.lifecycle:lifecycle-extensions:2.0.0-rc01
android.arch.lifecycle:livedata	androidx.lifecycle:lifecycle-livedata:2.0.0-rc01
android.arch.lifecycle:livedata-core	androidx.lifecycle:lifecycle-livedata-core:2.0.0-rc01
android.arch.lifecycle:reactivestreams	androidx.lifecycle:lifecycle-reactivestreams:2.0.0-rc01
android.arch.lifecycle:runtime	androidx.lifecycle:lifecycle-runtime:2.0.0-rc01
android.arch.lifecycle:viewmodel	androidx.lifecycle:lifecycle-viewmodel:2.0.0-rc01
android.arch.paging:common	androidx.paging:paging-common:2.0.0-rc01
android.arch.paging:runtime	androidx.paging:paging-runtime:2.0.0-rc01
android.arch.paging:rxjava2	androidx.paging:paging-rxjava2:2.0.0-rc01
android.arch.persistence.room:common	androidx.room:room-common:2.0.0-rc01
android.arch.persistence.room:compiler	androidx.room:room-compiler:2.0.0-rc01
android.arch.persistence.room:guava	androidx.room:room-guava:2.0.0-rc01
android.arch.persistence.room:migration	androidx.room:room-migration:2.0.0-rc01
android.arch.persistence.room:runtime	androidx.room:room-runtime:2.0.0-rc01
android.arch.persistence.room:rxjava2	androidx.room:room-rxjava2:2.0.0-rc01
android.arch.persistence.room:testing	androidx.room:room-testing:2.0.0-rc01
android.arch.persistence:db	androidx.sqlite:sqlite:2.0.0-rc01
android.arch.persistence:db-framework	androidx.sqlite:sqlite-framework:2.0.0-rc01
com.android.support.constraint:constraint-layout	androidx.constraintlayout:constraintlayout:1.1.2
com.android.support.constraint:constraint-layout-solver	androidx.constraintlayout:constraintlayout-solver:1.1.2
com.android.support.test.espresso.idling:idling-concurrent	androidx.test.espresso.idling:idling-concurrent:3.1.0
com.android.support.test.espresso.idling:idling-net	androidx.test.espresso.idling:idling-net:3.1.0
com.android.support.test.espresso:espresso-accessibility	androidx.test.espresso:espresso-accessibility:3.1.0
com.android.support.test.espresso:espresso-contrib	androidx.test.espresso:espresso-contrib:3.1.0
com.android.support.test.espresso:espresso-core	androidx.test.espresso:espresso-core:3.1.0
com.android.support.test.espresso:espresso-idling-resource	androidx.test.espresso:espresso-idling-resource:3.1.0
com.android.support.test.espresso:espresso-intents	androidx.test.espresso:espresso-intents:3.1.0
com.android.support.test.espresso:espresso-remote	androidx.test.espresso:espresso-remote:3.1.0
com.android.support.test.espresso:espresso-web	androidx.test.espresso:espresso-web:3.1.0
com.android.support.test.janktesthelper:janktesthelper	androidx.test.jank:janktesthelper:1.0.1
com.android.support.test.services:test-services	androidx.test:test-services:1.1.0
com.android.support.test.uiautomator:uiautomator	androidx.test.uiautomator:uiautomator:2.2.0
com.android.support.test:monitor	androidx.test:monitor:1.1.0
com.android.support.test:orchestrator	androidx.test:orchestrator:1.1.0
com.android.support.test:rules	androidx.test:rules:1.1.0
com.android.support.test:runner	androidx.test:runner:1.1.0
com.android.support:animated-vector-drawable	androidx.vectordrawable:vectordrawable-animated:1.0.0
com.android.support:appcompat-v7	androidx.appcompat:appcompat:1.0.0
com.android.support:asynclayoutinflater	androidx.asynclayoutinflater:asynclayoutinflater:1.0.0
com.android.support:car	androidx.car:car:1.0.0
com.android.support:cardview-v7	androidx.cardview:cardview:1.0.0
com.android.support:collections	androidx.collection:collection:1.0.0
com.android.support:coordinatorlayout	androidx.coordinatorlayout:coordinatorlayout:1.0.0
com.android.support:cursoradapter	androidx.cursoradapter:cursoradapter:1.0.0
com.android.support:customtabs	androidx.browser:browser:1.0.0
com.android.support:customview	androidx.customview:customview:1.0.0
com.android.support:design	com.google.android.material:material:1.0.0-rc01
com.android.support:documentfile	androidx.documentfile:documentfile:1.0.0
com.android.support:drawerlayout	androidx.drawerlayout:drawerlayout:1.0.0
com.android.support:exifinterface	androidx.exifinterface:exifinterface:1.0.0
com.android.support:gridlayout-v7	androidx.gridlayout:gridlayout:1.0.0
com.android.support:heifwriter	androidx.heifwriter:heifwriter:1.0.0
com.android.support:interpolator	androidx.interpolator:interpolator:1.0.0
com.android.support:leanback-v17	androidx.leanback:leanback:1.0.0
com.android.support:loader	androidx.loader:loader:1.0.0
com.android.support:localbroadcastmanager	androidx.localbroadcastmanager:localbroadcastmanager:1.0.0
com.android.support:media2	androidx.media2:media2:1.0.0-alpha03
com.android.support:media2-exoplayer	androidx.media2:media2-exoplayer:1.0.0-alpha01
com.android.support:mediarouter-v7	androidx.mediarouter:mediarouter:1.0.0
com.android.support:multidex	androidx.multidex:multidex:2.0.0
com.android.support:multidex-instrumentation	androidx.multidex:multidex-instrumentation:2.0.0
com.android.support:palette-v7	androidx.palette:palette:1.0.0
com.android.support:percent	androidx.percentlayout:percentlayout:1.0.0
com.android.support:preference-leanback-v17	androidx.leanback:leanback-preference:1.0.0
com.android.support:preference-v14	androidx.legacy:legacy-preference-v14:1.0.0
com.android.support:preference-v7	androidx.preference:preference:1.0.0
com.android.support:print	androidx.print:print:1.0.0
com.android.support:recommendation	androidx.recommendation:recommendation:1.0.0
com.android.support:recyclerview-selection	androidx.recyclerview:recyclerview-selection:1.0.0
com.android.support:recyclerview-v7	androidx.recyclerview:recyclerview:1.0.0
com.android.support:slices-builders	androidx.slice:slice-builders:1.0.0
com.android.support:slices-core	androidx.slice:slice-core:1.0.0
com.android.support:slices-view	androidx.slice:slice-view:1.0.0
com.android.support:slidingpanelayout	androidx.slidingpanelayout:slidingpanelayout:1.0.0
com.android.support:support-annotations	androidx.annotation:annotation:1.0.0
com.android.support:support-compat	androidx.core:core:1.0.0
com.android.support:support-content	androidx.contentpager:contentpager:1.0.0
com.android.support:support-core-ui	androidx.legacy:legacy-support-core-ui:1.0.0
com.android.support:support-core-utils	androidx.legacy:legacy-support-core-utils:1.0.0
com.android.support:support-dynamic-animation	androidx.dynamicanimation:dynamicanimation:1.0.0
com.android.support:support-emoji	androidx.emoji:emoji:1.0.0
com.android.support:support-emoji-appcompat	androidx.emoji:emoji-appcompat:1.0.0
com.android.support:support-emoji-bundled	androidx.emoji:emoji-bundled:1.0.0
com.android.support:support-fragment	androidx.fragment:fragment:1.0.0
com.android.support:support-media-compat	androidx.media:media:1.0.0
com.android.support:support-tv-provider	androidx.tvprovider:tvprovider:1.0.0
com.android.support:support-v13	androidx.legacy:legacy-support-v13:1.0.0
com.android.support:support-v4	androidx.legacy:legacy-support-v4:1.0.0
com.android.support:support-vector-drawable	androidx.vectordrawable:vectordrawable:1.0.0
com.android.support:swiperefreshlayout	androidx.swiperefreshlayout:swiperefreshlayout:1.0.0
com.android.support:textclassifier	androidx.textclassifier:textclassifier:1.0.0
com.android.support:transition	androidx.transition:transition:1.0.0
com.android.support:versionedparcelable	androidx.versionedparcelable:versionedparcelable:1.0.0
com.android.support:viewpager	androidx.viewpager:viewpager:1.0.0
com.android.support:wear	androidx.wear:wear:1.0.0
com.android.support:webkit	androidx.webkit:webkit:1.0.0

类映射

下表列出了部分常用的从旧命名空间到新 androidx 包的当前映射，也可以下载CSV格式映射文件：

支持库类	AndroidX 类
android.support.multidex.MultiDex	androidx.multidex.MultiDex
android.support.v4.app.ActivityCompat	androidx.core.app.ActivityCompat
android.support.v4.app.ActivityManagerCompat	androidx.core.app.ActivityManagerCompat
android.support.v4.app.ActivityOptionsCompat	androidx.core.app.ActivityOptionsCompat
android.support.v4.app.AlarmManagerCompat	androidx.core.app.AlarmManagerCompat
android.support.v4.app.BundleCompat	androidx.core.app.BundleCompat
android.support.v4.app.DialogFragment	androidx.fragment.app.DialogFragment
android.support.v4.app.Fragment	androidx.fragment.app.Fragment
android.support.v4.app.FragmentActivity	androidx.fragment.app.FragmentActivity
android.support.v4.app.FragmentManager	androidx.fragment.app.FragmentManager
android.support.v4.app.ListFragment	androidx.fragment.app.ListFragment
android.support.v4.app.LoaderManager	androidx.loader.app.LoaderManager
android.support.v4.app.NotificationCompat	androidx.core.app.NotificationCompat
android.support.v4.app.NotificationCompatBuilder	androidx.core.app.NotificationCompatBuilder
android.support.v4.app.NotificationManagerCompat	androidx.core.app.NotificationManagerCompat
android.support.v4.content.ContextCompat	androidx.core.content.ContextCompat
android.support.v4.content.CursorLoader	androidx.loader.content.CursorLoader
android.support.v4.content.FileProvider	androidx.core.content.FileProvider
android.support.v4.graphics.BitmapCompat	androidx.core.graphics.BitmapCompat
android.support.v4.graphics.ColorUtils	androidx.core.graphics.ColorUtils
android.support.v4.graphics.PaintCompat	androidx.core.graphics.PaintCompat
android.support.v4.graphics.PathParser	androidx.core.graphics.PathParser
android.support.v4.math.MathUtils	androidx.core.math.MathUtils
android.support.v4.util.LruCache	androidx.collection.LruCache
android.support.v4.util.Pair	androidx.core.util.Pair
android.support.v4.util.TimeUtils	androidx.core.util.TimeUtils
android.support.v4.widget.AutoScrollHelper	androidx.core.widget.AutoScrollHelper
android.support.v4.widget.AutoSizeableTextView	androidx.core.widget.AutoSizeableTextView
android.support.v4.widget.CircleImageView	androidx.swiperefreshlayout.widget.CircleImageView
android.support.v4.widget.DrawerLayout	androidx.drawerlayout.widget.DrawerLayout
android.support.v7.app.AlertDialog	androidx.appcompat.app.AlertDialog
android.support.v7.app.AppCompatActivity	androidx.appcompat.app.AppCompatActivity
android.support.v7.app.AppCompatDialog	androidx.appcompat.app.AppCompatDialog
android.support.v7.widget.CardView	androidx.cardview.widget.CardView
android.support.v7.widget.GridLayout	androidx.gridlayout.widget.GridLayout
android.support.v7.widget.GridLayoutManager	androidx.recyclerview.widget.GridLayoutManager