【发布时间】：2018-07-04 16:31:44
【问题描述】：
我有一个多模块 Android 项目，使用 Kotlin，数据绑定 v2，在 Android Studio 3.1.3 下。我的大多数支持数据绑定的布局都包含在库模块中，最终应用程序模块会聚合这些模块。
当我想在我的应用程序模块中添加新布局或从库模块之一覆盖布局时，问题就开始了。将带有<layout> 标记的测试布局添加到应用程序模块后，数据绑定停止生成，并出现以下错误：
error: cannot find symbol
public static TestBinding bind(@NonNull View view, @Nullable DataBindingComponent component) {
^
symbol: class DataBindingComponent
location: class TestBinding
e: error: cannot generate view binders java.lang.NullPointerException
at android.databinding.tool.store.SetterStore.getMatchingMultiAttributeSetters(SetterStore.java:633)
at android.databinding.tool.store.SetterStore.getMultiAttributeSetterCalls(SetterStore.java:520)
at android.databinding.tool.BindingTarget.resolveMultiSetters(BindingTarget.java:220)
at android.databinding.tool.LayoutBinder.<init>(LayoutBinder.java:256)
at android.databinding.tool.DataBinder.<init>(DataBinder.java:55)
at android.databinding.tool.CompilerChef.ensureDataBinder(CompilerChef.java:95)
at android.databinding.tool.CompilerChef.sealModels(CompilerChef.java:259)
at android.databinding.annotationprocessor.ProcessExpressions.writeResourceBundle(ProcessExpressions.java:213)
at android.databinding.annotationprocessor.ProcessExpressions.onHandleStep(ProcessExpressions.java:111)
at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.runStep(ProcessDataBinding.java:203)
at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.access$000(ProcessDataBinding.java:188)
at android.databinding.annotationprocessor.ProcessDataBinding.doProcess(ProcessDataBinding.java:90)
at android.databinding.annotationprocessor.ProcessDataBinding.process(ProcessDataBinding.java:65)
at org.jetbrains.kotlin.kapt3.ProcessorWrapper.process(annotationProcessing.kt:131)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.callProcessor(JavacProcessingEnvironment.java:794)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.discoverAndRunProcs(JavacProcessingEnvironment.java:705)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.access$1800(JavacProcessingEnvironment.java:91)
at com.sun.tools.javac.processing.JavacProcessingEnvironment$Round.run(JavacProcessingEnvironment.java:1035)
at com.sun.tools.javac.processing.JavacProcessingEnvironment.doProcessing(JavacProcessingEnvironment.java:1176)
at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1170)
at com.sun.tools.javac.main.JavaCompiler.processAnnotations(JavaCompiler.java:1068)
at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:87)
at org.jetbrains.kotlin.kapt3.AnnotationProcessingKt.doAnnotationProcessing$default(annotationProcessing.kt:45)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.runAnnotationProcessing(Kapt3Extension.kt:257)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.analysisCompleted(Kapt3Extension.kt:212)
at org.jetbrains.kotlin.kapt3.ClasspathBasedKapt3Extension.analysisCompleted(Kapt3Extension.kt:95)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM$analyzeFilesWithJavaIntegration$2.invoke(TopDownAnalyzerFacadeForJVM.kt:97)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:107)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:84)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:374)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:64)
at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:101)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:365)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:130)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:161)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:63)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:107)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.java:51)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:96)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:405)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:98)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:920)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$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:950)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.doCompile(CompileServiceImpl.kt:919)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:404)
at sun.reflect.GeneratedMethodAccessor101.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:357)
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:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
库模块中的所有DataBindingComponent接口正在生成，只有应用程序模块中的一个没有生成。
【问题讨论】：
-
对于它的价值，我们也使用了一个多模块项目，除了我们有一个库模块和多个应用程序模块。虽然我们通常不会覆盖应用程序模块中的库布局，但我现在已经对其进行了测试，并且运行良好。只有我们的单元测试在 Kotlin 中，其余的是 Java。 Android Studio 3.1.2.
-
问题的根本原因是 github.com/woxblom/DragListView 添加为
implementation依赖项到库项目之一。将其更改为api依赖项解决了该问题。不过奇怪的是，lib 本身不包含任何数据。
标签： android kotlin android-databinding