我正在为我的应用程序添加抽屉导航。我收到错误。应用程序 gradle 同步就好了。但是当我运行该应用程序时，出现了一堆重复的类错误。我认为这可能是因为我添加了相互冲突的依赖项并且我使用的是 v7 28.0.0 并且一些错误提到了 app: v4.我在网上看到的所有示例都使用 v7 28.0.0，尽管我在使用 v4 的 main_activity.xml 中有这个。不知道它是否与错误有关。 android.support.v4.widget.DrawerLayout

Caused by: com.android.ide.common.workers.WorkerExecutorException: 1 exception was raised by workers:
java.lang.RuntimeException: java.lang.RuntimeException: Duplicate class android.support.v4.accessibilityservice.AccessibilityServiceInfoCompat found in modules classes.jar (com.android.support:support-compat:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActionBarDrawerToggle found in modules classes.jar (com.android.support:support-core-ui:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActionBarDrawerToggle$Delegate found in modules classes.jar (com.android.support:support-core-ui:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActionBarDrawerToggle$DelegateProvider found in modules classes.jar (com.android.support:support-core-ui:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActionBarDrawerToggle$SlideDrawable found in modules classes.jar (com.android.support:support-core-ui:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActivityCompat found in modules classes.jar (com.android.support:support-compat:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActivityCompat$1 found in modules classes.jar (com.android.support:support-compat:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)
Duplicate class android.support.v4.app.ActivityCompat$OnRequestPermissionsResultCallback found in modules classes.jar (com.android.support:support-compat:28.0.0) and classes.jar (com.android.support:support-v4:24.0.0)

渐变文件

apply plugin: 'com.android.application'

android {    
    
    compileSdkVersion 28
    defaultConfig {
        applicationId "org.pctechtips.netdroid"
        minSdkVersion 21
        targetSdkVersion 28
        versionCode 8
        versionName "1.7"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
        multiDexEnabled = false
        signingConfig signingConfigs.config
    }
    buildTypes {
        release {
            shrinkResources false
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            debuggable false

        }
    }
}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support:design:28.0.0'
    /*androidTestImplementation('com.android.support.test.espresso:espresso-core:2.2.2', {
                        exclude group: 'com.android.support', module: 'support-annotations'
                        firebase
                        implementation 'com.google.firebase:firebase-core:10.2.1'
                    })*/
    //    compile 'com.android.support:appcompat-v7:25.3.0'
    implementation 'com.android.support.constraint:constraint-layout:1.0.2'
    testImplementation 'junit:junit:4.12'
    /*google play plugin for adMob*/
    implementation 'com.google.android.gms:play-services:10.2.1'
    implementation 'commons-net:commons-net:3.6'
    implementation 'org.samba.jcifs:jcifs:1.3.3'
}

最佳答案

异常意味着，在 2 个或更多不同的依赖项中存在重复的类，编译器将无法区分应该在 run-time 中使用它们中的哪些，因此抛出异常。

大多数情况下，口是心非发生在您尝试导入带有所需库的模块时。 (传递依赖)

您必须从 build.gradle 中的库中排除 重复的类。 如日志所示，support-core-ui 和 support-compat 模块具有重复的类。

apply plugin: 'com.android.application'

android {
    ...
    defaultConfig {
        ...
    }
    buildTypes {
        ...
    }
    configurations {
        all { // You should exclude one of them not both of them 
            exclude group: "com.android.support", module: "support-core-ui"
            exclude group: "com.android.support", module: "support-compat"
        }
    }
}

有时您不需要排除任何东西，您只需要将导入的模块更改为不带来其依赖项的模块。

其他情况 导致重复类 是当您将*.jar 添加到项目libs 目录时.因此，如果项目中没有开始使用它们，您需要将它们删除。

project->app->libs->*.jar

我看到有一些解决方案提到使用这两行可以解决问题但是如果你已经迁移到 Androidx 它会默认启用。

android.useAndroidX=true
android.enableJetifier=true

Jetifier 是

Jetifier tool migrates support-library-dependent libraries to rely on the equivalent AndroidX packages instead. The tool lets you migrate an individual library directly, instead of using the Android gradle plugin bundled with Android Studio.

有关更多信息，请查看 Exclude transitive dependencies

As an app grows in scope, it can contain a number of dependencies including direct dependencies and transitive dependencies (libraries which your app's imported libraries depend on). To exclude transitive dependencies that you no longer need, you can use the exclude keyword

如果您在排除类时遇到问题，请检查此线程:How do I exclude...

关于android - 为什么我在运行我的 Android 项目时会得到重复的类，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/56029393/