一、问题
今天在学Android布局，在导入百分比布局时总报错，查了资料，又说
PercentFrameLayout
过时了。但是我要学这个啊~
二、不推荐的解决方案
如果你的上下文没有写
implementation "androidx..."
那么可以用下列两个方案：
-
方案一：
参考资料一
先选择离线
Grandle
-
方案二：
参考资料二
在sdk里找到对应的版本，然后再引入
三、推荐的解决方案
如果你仔细观察，会发现上下其他的库引入时都写着
androidX
。
实际上，现有的软件包，如本文的
android.support
库，被重构为
Androidx
。尽管在
Google Maven
上仍然提供支持库版本27及更低版本，但所有新开发将包含在Androidx 1.0.0及更高版本中。也就是说：AndroidX完全取代了支持库，不仅提供同等的功能，而且提供了新的库。
而且，只有软件包和 Maven 工件名称发生了变化；类、方法和字段名称没有改变。
所以，按照对应表【见附录】，此处的引用应该是：
这样就没有错了：
四、附录：其他对应的新旧库转换
| Old build artifact | AndroidX build artifact |
|---|---|
| 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🏃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🚗1.0.0-alpha5 |
| 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 |
| Old build artifact | AndroidX build artifact |
|---|---|
| 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 |
| 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 |