Question

我可以成功构建并运行一个全新的flutter项目。但是，当我将image_cropper: ^1.0.0和contacts_service: ^0.2.4软件包都添加到pubspec.yaml并运行flutter packages get时，我无法再构建项目，并得到以下构建错误：

D8: Program type already present: android.support.v4.app.INotificationSideChannel

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:transformDexArchiveWithExternalLibsDexMergerForDebug'.
> com.android.builder.dexing.DexArchiveMergerException: Error while merging dex archives: E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\2.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\3.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\4.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\5.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\6.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\7.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\8.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\9.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\10.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\11.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\12.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\13.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\14.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\15.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\16.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\17.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\18.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\19.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\20.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\21.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\22.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\23.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\24.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\25.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\26.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\27.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\28.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\29.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\30.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\31.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\32.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\33.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\34.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\35.jar, E:\Projects\flutter\hello\build\app\intermediates\transforms\dexBuilder\debug\36.jar
  Learn how to resolve the issue at https://developer.android.com/studio/build/dependencies#duplicate_classes.
  Program type already present: android.support.v4.app.INotificationSideChannel

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 1m 19s
*******************************************************************************************
The Gradle failure may have been because of AndroidX incompatibilities in this Flutter app.
See https:///CP92wY for more information on the problem and how to fix it.
*******************************************************************************************
Finished with error: Gradle task assembleDebug failed with exit code 1

我不太清楚这个错误，但是似乎这两个软件包之间存在命名冲突（因为错误文本中的duplicate_classes）。有什么解决方法吗？

请注意，对于我来说，任何其他一对软件包都不会发生此错误。

Answer 1

在build.gradle defaultConfig中添加multiDexEnabled true

Answer 2

这是一个Android X兼容性问题。我可以按照here中提到的步骤进行修复，但总而言之：

首先确保app / build.gradle中的compileSdkVersion至少为28。此属性控制Gradle用于构建APK的Android SDK的版本。它不会影响您的应用可以运行的最低SDK版本。
右键单击flutter项目的android目录，然后使用以下菜单打开它：Flutter > Open android module in android studio
在新打开的项目中，从菜单中选择Refactor > Migrate to AdnroidX
关闭项目，然后再次打开您的flutter项目。

Flutter：添加“ image_cropper”和“ contacts_service”软件包时生成错误

2 个答案: