android.support已死，androidx当立——弃用support库指南

前言
androidx 是对 android.support.xxx 包的整理后产物。由于之前的support包过于混乱，所以，google推出了 androidX。

自support v7:28.+开始，大部分support包都会迁移到androidx下，，所以建议开发者们尽早将项目转移到androidx下

迁移步骤
1.先备份项目！
2.使用Android Studio自动迁移
在菜单栏中依次进入Refactor > Migrate to AndroidX，之后as会提示备份项目，如果已备份就不用勾选备份选项。

迁移完成之后，gradle.properties里会多出这两行

android.useAndroidX=true
android.enableJetifier=true

如果你的项目中没有使用任何三方依赖，那么android.enableJetifier可以设置为false

3. 旧依赖包名与新包名对照表（建议使用Ctrl + F搜索）
执行Migrate to AndroidX完成之后，虽然常用的support包都会被转成对应的androidx里的包名，但还是依然有部分包名未能转换成功，这时候需要我们手动修改。转载请注明出处，本文来自https://blog.csdn.net/yin_ol/article/details/89421390

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

参考 https://developer.android.google.cn/topic/libraries/support-library/refactor