错误：com.app.android.dagger.component.AppComponent（unscoped）可能不引用作用域绑定：

Question

嗨我在我的Android应用程序中使用dagger2。我有AppModule和AppComponent，它提供ConnectivityManager。

AppModule.kt

@Module
class AppModule(private val application: Application) {

    @Provides
    @Singleton
    fun providesApplication(): Application = application

    @Provides
    @Singleton
    fun providesConnectivityManager(): ConnectivityManager = application.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
}

AppComponent.kt

@Component(modules = arrayOf(AppModule::class))
interface AppComponent {
    fun inject(app: ApprApplication)
}

在我的应用程序类中，我正在注入ConnectivityManager，但是当我记录时，我得到的值为null。

class AppApplication : Application(), AnkoLogger {

    private val appComponent: AppComponent by lazy {
        DaggerAppComponent.builder().appModule(AppModule(this)).build()
    }

    lateinit @Inject
    var cm: ConnectivityManager

    override fun onCreate() {
        super.onCreate()
        appComponent.inject(this)

        info {
            "connectivity manager ${cm}"
        }
    }
}

堆栈跟踪：

$ gradlew build

> Configure project :app
NDK is missing a "platforms" directory.
If you are using NDK, verify the ndk.dir is set to a valid NDK directory.  It is currently set to C:\android-ndk-r15.
If you are not using NDK, unset the NDK variable from ANDROID_NDK_HOME or local.properties to remove this warning.


> Task :app:kaptGenerateStubsDebugKotlin
Using kotlin incremental compilation

e: D:\android\appandroid\app\app\build\tmp\kapt3\stubs\debug\com\app\android\dagger\component\AppComponent.java:4: error: com.app.android.dagger.component.AppComponent (unscoped) may not reference scoped bindings:
e:

e: @dagger.Component(modules = {com.app.android.dagger.module.AppModule.class})
e: ^
e:       @org.jetbrains.annotations.NotNull @Singleton @Provides android.net.ConnectivityManager com.app.android.dagger.module.AppModule.providesConnectivityManager()
e: java.lang.IllegalStateException: failed to analyze: org.jetbrains.kotlin.kapt3.diagnostic.KaptError: Error while annotation processing
        at org.jetbrains.kotlin.analyzer.AnalysisResult.throwIfError(AnalysisResult.kt:57)
        at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules(KotlinToJVMBytecodeCompiler.kt:138)
        at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:170)
        at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:58)
        at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:93)
        at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:46)
        at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:92)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$2.invoke(CompileServiceImpl.kt:386)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$2.invoke(CompileServiceImpl.kt:98)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:832)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:98)
        at org.jetbrains.kotlin.daemon.common.DummyProfiler.withMeasure(PerfUtils.kt:137)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl.checkedCompile(CompileServiceImpl.kt:859)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl.doCompile(CompileServiceImpl.kt:831)
        at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:385)
        at sun.reflect.GeneratedMethodAccessor80.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at sun.rmi.server.UnicastServerRef.dispatch(UnicastServerRef.java:346)
        at sun.rmi.transport.Transport$1.run(Transport.java:200)
        at sun.rmi.transport.Transport$1.run(Transport.java:197)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
        at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:568)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:826)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:683)
        at java.security.AccessController.doPrivileged(Native Method)
        at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:682)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
        at java.lang.Thread.run(Thread.java:745)
Caused by: org.jetbrains.kotlin.kapt3.diagnostic.KaptError: Error while annotation processing
        at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:90)
        at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing$default(annotationProcessing.kt:42)
        at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.runAnnotationProcessing(Kapt3Extension.kt:205)
        at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.analysisCompleted(Kapt3Extension.kt:166)
        at org.jetbrains.kotlin.kapt3.ClasspathBasedKapt3Extension.analysisCompleted(Kapt3Extension.kt:82)
        at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM$analyzeFilesWithJavaIntegration$2.invoke(TopDownAnalyzerFacadeForJVM.kt:96)
        at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:106)
        at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:83)
        at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:377)
        at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:68)
        at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:96)
        at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:368)
        at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules(KotlinToJVMBytecodeCompiler.kt:133)
        ... 29 more


FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':app:kaptDebugKotlin'.
> Internal compiler error. See log for more details

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

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

BUILD FAILED in 7s
13 actionable tasks: 2 executed, 11 up-to-date

当我从provideConnectivityManager中删除@Singleton时，它运行良好。有谁知道这里有什么问题？

Answer 1

您需要将@Singleton添加到AppComponent类：

@Singleton
@Component(modules = arrayOf(AppModule::class))
interface AppComponent {
    fun inject(app: ApprApplication)
}