java - 即使我所有的 XML 文件都没有错误，也不会生成 R.java

Question

我在 Android Studio(3.1.3，内部版本 173.4819257)中开发我的应用时遇到了臭名昭著的 R 缺失问题。我尝试了很多解决方案，例如:

• 清理和重建
• 将项目与 Gradle 文件同步
• 使缓存失效并重新启动
• 更正我的 XML 文件(包括布局和 list )中的所有错误和警告
• 关闭 Android Studio 并重启
• 缩短包名和目录路径

这是我的 list 。我是 Android 开发的新手，所以我可能误解了一些东西。

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.n.nomoko">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme"
        android:fullBackupContent="true"
        tools:ignore="GoogleAppIndexingWarning">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service
            android:name=".logic.ChallengeService"
            android:process=":defis" />

        <activity android:name=".views.AccueilActivity" />
        <activity android:name=".views.InscriptionActivity">

        </activity>
    </application>

</manifest>

此外，这是我的存储库树，如果它有帮助的话。

我的问题是:manifest 中是否存在关于我的包或路径的问题？为什么 R.java 没有生成，即使所有的 XML 文件都是正确的？感谢您的帮助:)

[编辑]

这是我的应用程序>build.gradle

    apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.nomokoteam.nomoko"
        minSdkVersion 23
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}

[编辑] 这是编译器日志:

org.gradle.api.internal.tasks.compile.CompilationFailedException: Compilation failed; see the compiler error output for details.
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:52)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJavaCompiler.java:36)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegateAndHandleErrors(NormalizingJavaCompiler.java:100)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:52)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute(NormalizingJavaCompiler.java:38)
at org.gradle.api.internal.tasks.compile.AnnotationProcessorDiscoveringCompiler.execute(AnnotationProcessorDiscoveringCompiler.java:49)
at org.gradle.api.internal.tasks.compile.AnnotationProcessorDiscoveringCompiler.execute(AnnotationProcessorDiscoveringCompiler.java:35)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.execute(CleaningJavaCompilerSupport.java:39)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalCompilerFactory$2.execute(IncrementalCompilerFactory.java:110)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalCompilerFactory$2.execute(IncrementalCompilerFactory.java:106)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringCompiler.execute(IncrementalResultStoringCompiler.java:59)
at org.gradle.api.internal.tasks.compile.incremental.IncrementalResultStoringCompiler.execute(IncrementalResultStoringCompiler.java:43)
at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompile.java:153)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:121)
at com.android.build.gradle.tasks.AndroidJavaCompile.compile(AndroidJavaCompile.kt:233)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:73)
at org.gradle.api.internal.project.taskfactory.IncrementalTaskAction.doExecute(IncrementalTaskAction.java:50)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:39)
at org.gradle.api.internal.project.taskfactory.StandardTaskAction.execute(StandardTaskAction.java:26)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter$1.run(ExecuteActionsTaskExecuter.java:131)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:300)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:292)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:174)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeAction(ExecuteActionsTaskExecuter.java:120)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.executeActions(ExecuteActionsTaskExecuter.java:99)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.execute(ExecuteActionsTaskExecuter.java:77)
at org.gradle.api.internal.tasks.execution.OutputDirectoryCreatingTaskExecuter.execute(OutputDirectoryCreatingTaskExecuter.java:51)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter$1.run(EventFiringTaskExecuter.java:51)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:300)
at org.gradle.internal.operations.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:292)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:174)
at org.gradle.internal.operations.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:90)
at org.gradle.internal.operations.DelegatingBuildOperationExecutor.run(DelegatingBuildOperationExecutor.java:31)
at org.gradle.api.internal.tasks.execution.EventFiringTaskExecuter.execute(EventFiringTaskExecuter.java:46)
at org.gradle.execution.taskgraph.LocalTaskInfoExecutor.execute(LocalTaskInfoExecutor.java:42)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareWorkItemExecutor.execute(DefaultTaskExecutionGraph.java:277)
at org.gradle.execution.taskgraph.DefaultTaskExecutionGraph$BuildOperationAwareWorkItemExecutor.execute(DefaultTaskExecutionGraph.java:262)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:135)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:130)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.execute(DefaultTaskPlanExecutor.java:200)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.executeWithWork(DefaultTaskPlanExecutor.java:191)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$ExecutorWorker.run(DefaultTaskPlanExecutor.java:130)
at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
at java.lang.Thread.run(Thread.java:745)

我在这里找到了它们:

[编辑]

我在 app/build/generated/not_namespaced_r_class_sources/debug/processDebugResources/r/com/n/nomoko/文件夹中找到了 R.java。所以，我的猜测是 R 可以正确生成(我将其删除并进行了清理 + 重建，然后它重新出现)但不是在正确的位置。我对吗 ？这是我的存储库树:

Answer 1

关闭然后重新导入项目有时会修复奇怪的 Android Studio 问题。