问题
I recently updated my Android Studio (and I'm pretty sure the Gradle version), and now I've been getting a bunch of errors when trying to compile my project. Here's the one that is plaguing me at the moment:
Duplicate class android.support.v4.app.INotificationSideChannel found in modules classes.jar (androidx.core:core:1.0.1) and classes.jar (com.android.support:support-compat:26.1.0)
This is followed by lots of similar ones.
I tried removing all uses of com.android.support in favor of androidx (see here for what I was using the replace things), but com.android.support libraries are still being used, even when I delete the libraries (they're just remade once I try to compile again).
Here's a link to the full error I get.
回答1:
I hope you have in your gradle.properties these two lines:
(If you don't have a gradle.properties, then simply create it in the root directory of your project)
android.useAndroidX=true
android.enableJetifier=true
It looks like you have some support relics any where in your dependencies, maybe form a lib ?
To investigate and see the dependencies tree, please run
./gradlew :yourApp:dependencies
and then you see from where it comes.
回答2:
In your app build.gradle you are using a mix of old support library and new support library artifacts. Remove one of them from your build.gradle to resolve this issue.
Old artifact: com.android.support:support-compat
Corresponding new artifact: androidx.core:core:1.0.0
See this page for more information on migrating to AndroidX.
回答3:
This solution from here worked the best for me. Migrating to androidX
https://developer.android.com/jetpack/androidx/migrate
With Android Studio 3.2 and higher, you can migrate an existing project to AndroidX by selecting Refactor > Migrate to AndroidX from the menu bar.
The refactor command makes use of two flags. By default, both of them are set to true in your gradle.properties file:
android.useAndroidX=trueThe Android plugin uses the appropriate AndroidX library instead of a Support Library. android.enableJetifier=true The Android plugin automatically migrates existing third-party libraries to use AndroidX by rewriting their binaries.
回答4:
Like others says, the solution is to migrating to AndroidX, it works for me. However, it isn´t an easy way and it requires a bit of pacience... These are the steps that I did:
First, is very important that you do all this changes in a different branch or you make a backup of your project.
You need to have the Android Gradle Plugin Version 3.5.1. So, in build.gradle set:
dependencies { classpath 'com.android.tools.build:gradle:3.5.1' ...- Migrate to AndroidX using Android Studio Tool : Refactor --> Migrate to AndroidX...
When it finishes, it has done all pertinents modification, but posibly you can´t deploy the project correctly because you find any errors. These are the problems that I found and the solutions:
If you use Kotlin, in build.gradle set:
buildscript { ext.kotlin_version = '1.3.10' ...andcompile "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"- If you use destination method, add "file" parameter:
destination file("$reportsDir/checkstyle/checkstyle.xml") - If you use Butterknife, use 10.0.0 version
- Finally, Build --> Clean Project and Build --> Rebuild Project
回答5:
go to the Gradle Scrpits->gradle.properties and then paste this code :
- android.useAndroidX=true
- android.enableJetifier=true
and rebulid your project. good luck :)
来源：https://stackoverflow.com/questions/55756647/duplicate-classes-from-androidx-and-com-android-support