[请帮助。该类中有一个Int字段isNew。不要问为什么要Int，有必要。视图中有一个切换按钮。
<Switch
android:id="@+id/switch_is_new_part"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="@dimen/margin_8"
android:layout_marginBottom="@dimen/margin_8"
android:text="SwitchButtonNew"
android:textSize="18sp"
android:checked="@={Converter.convertToBoolean(detail.isNew)}"
tools:visibility="visible" />
我正在尝试使用双向数据绑定和转换器将int转换为布尔值类转换器
public class Converter {
public static boolean convertToBoolean(int checked){
if(checked==1) return true; else return false;
}
@InverseMethod("convertToBoolean")
public static int convertToInt(boolean checked){
if(checked) return 1; else return 0;
}
}
如果使用单向绑定（@ {Converter.convertToBoolean（detail.isNew）}}，则所有内容都会编译。如果我尝试进行双向绑定（@ = {Converter.convertToBoolean（detail.isNew）}），编译会因错误而崩溃：
e: error: cannot generate view binders java.lang.NullPointerException
at android.databinding.tool.expr.Expr.lambda$join$0(Expr.java:770)
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
at java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:708)
at java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:499)
at android.databinding.tool.expr.Expr.join(Expr.java:771)
at android.databinding.tool.expr.Expr.join(Expr.java:766)
at android.databinding.tool.expr.MethodCallExpr.computeUniqueKey(MethodCallExpr.java:244)
at android.databinding.tool.expr.Expr.getUniqueKey(Expr.java:480)
at android.databinding.tool.expr.ExprModel.register(ExprModel.java:120)
at android.databinding.tool.expr.CallbackExprModel.register(CallbackExprModel.java:60)
at android.databinding.tool.expr.ExprModel.methodCall(ExprModel.java:305)
at android.databinding.tool.expr.FieldAccessExpr.generateInverse(FieldAccessExpr.java:428)
at android.databinding.tool.expr.MethodCallExpr.generateInverse(MethodCallExpr.java:311)
at android.databinding.tool.InverseBinding.<init>(InverseBinding.java:65)
at android.databinding.tool.BindingTarget.addInverseBinding(BindingTarget.java:70)
at android.databinding.tool.LayoutBinder.<init>(LayoutBinder.java:134)
at android.databinding.tool.DataBinder.<init>(DataBinder.java:60)
at android.databinding.tool.CompilerChef.ensureDataBinder(CompilerChef.java:117)
at android.databinding.tool.CompilerChef.sealModels(CompilerChef.java:369)
at android.databinding.annotationprocessor.ProcessExpressions.writeResourceBundle(ProcessExpressions.java:244)
at android.databinding.annotationprocessor.ProcessExpressions.onHandleStep(ProcessExpressions.java:126)
at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.runStep(ProcessDataBinding.java:247)
at android.databinding.annotationprocessor.ProcessDataBinding$ProcessingStep.access$000(ProcessDataBinding.java:232)
at android.databinding.annotationprocessor.ProcessDataBinding.doProcess(ProcessDataBinding.java:113)
at android.databinding.annotationprocessor.ProcessDataBinding.process(ProcessDataBinding.java:88)
at org.jetbrains.kotlin.kapt3.base.incremental.IncrementalProcessor.process(incrementalProcessors.kt)
at org.jetbrains.kotlin.kapt3.base.ProcessorWrapper.process(annotationProcessing.kt:132)
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.base.AnnotationProcessingKt.doAnnotationProcessing(annotationProcessing.kt:80)
at org.jetbrains.kotlin.kapt3.base.AnnotationProcessingKt.doAnnotationProcessing$default(annotationProcessing.kt:36)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.runAnnotationProcessing(Kapt3Extension.kt:223)
at org.jetbrains.kotlin.kapt3.AbstractKapt3Extension.analysisCompleted(Kapt3Extension.kt:187)
at org.jetbrains.kotlin.kapt3.ClasspathBasedKapt3Extension.analysisCompleted(Kapt3Extension.kt:98)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM$analyzeFilesWithJavaIntegration$2.invoke(TopDownAnalyzerFacadeForJVM.kt:95)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(TopDownAnalyzerFacadeForJVM.kt:105)
at org.jetbrains.kotlin.cli.jvm.compiler.TopDownAnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration$default(TopDownAnalyzerFacadeForJVM.kt:80)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:398)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$analyze$1.invoke(KotlinToJVMBytecodeCompiler.kt:65)
at org.jetbrains.kotlin.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.kt:107)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.kt:389)
at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:118)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:166)
at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:56)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:84)
at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:42)
at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:104)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:442)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$compile$1$1$2.invoke(CompileServiceImpl.kt:102)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:1005)
at org.jetbrains.kotlin.daemon.CompileServiceImpl$doCompile$$inlined$ifAlive$lambda$2.invoke(CompileServiceImpl.kt:102)
at org.jetbrains.kotlin.daemon.common.DummyProfiler.withMeasure(PerfUtils.kt:138)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.checkedCompile(CompileServiceImpl.kt:1047)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.doCompile(CompileServiceImpl.kt:1004)
at org.jetbrains.kotlin.daemon.CompileServiceImpl.compile(CompileServiceImpl.kt:441)
at sun.reflect.GeneratedMethodAccessor113.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$1.run(Transport.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.Transport.serviceCall(Transport.java:196)
at sun.rmi.transport.tcp.TCPTransport.handleMessages(TCPTransport.java:573)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run0(TCPTransport.java:834)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.lambda$run$0(TCPTransport.java:688)
at java.security.AccessController.doPrivileged(Native Method)
at sun.rmi.transport.tcp.TCPTransport$ConnectionHandler.run(TCPTransport.java:687)
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)
> Task :app:kaptDebugKotlin FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':app:kaptDebugKotlin'.
> Compilation error. See log for more details
我在哪里弄错了？
注解@InverseMethod应该添加到双向绑定表达式中调用的函数中。所以
public class Converter {
public static boolean convertToBoolean(int checked)
@InverseMethod("convertToBoolean")
public static int convertToInt(boolean checked)
}
应更改为
public class Converter {
@InverseMethod("convertToInt")
public static boolean convertToBoolean(int checked)
public static int convertToInt(boolean checked)
}