在Android Studio中找不到符号变量错误

我正在尝试构建一个应用程序，它以固定的间隔获取位置数据，并在地图上绘制指针

下面的函数是我构造的：

private void drawLocations() {
    // Get only latest logged locations - since 'START' button clicked
    Query queryRef =
            myFirebaseRef.orderByChild("timestamp").startAt(startLoggingTime);
    // Add listener for a child added at the data at this location
    queryRef.addChildEventListener(new ChildEventListener() {
        LatLngBounds bounds;
        LatLngBounds.Builder builder = new LatLngBounds.Builder();
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            Map  data = (Map ) dataSnapshot.getValue();
            String timestamp = (String) data.get("timestamp");
            // Get recorded latitude and longitude
            Map  mCoordinate = (HashMap)data.get("location");
            double latitude = (double) (mCoordinate.get("latitude"));
            double longitude = (double) (mCoordinate.get("longitude"));

            // Create LatLng for each locations
            LatLng mLatlng = new LatLng(latitude, longitude);

            // Make sure the map boundary contains the location
            builder.include(mLatlng);
            bounds = builder.build();

            // Add a marker for each logged location
            MarkerOptions mMarkerOption = new MarkerOptions()
                    .position(mLatlng)
                    .title(timestamp)
                    .icon(BitmapDescriptorFactory.fromResource(R.drawable.pointer));
            Marker mMarker = mMap.addMarker(mMarkerOption);
            markerList.add(mMarker);

            // Zoom map to the boundary that contains every logged location
            mMap.animateCamera(CameraUpdateFactory.newLatLngBounds(bounds,
                    MAP_ZOOM_LEVEL));
        }

我收到错误：

错误：（274，78）错误：找不到符号变量指针

我查看了其他问题，其中有人建议导入错误的R文件。但奇怪的是，代码前面有一行：

MarkerOptions mMarkerOption = new MarkerOptions()
                .position(mLatlng)
                .title(mLastUpdateTime)
                .icon(BitmapDescriptorFactory.fromResource(R.drawable.bus));

而且

R.drawable.bus似乎没有错误

我说似乎是因为gradle构建说它完成时有2个错误，虽然我认为这不是第二个错误问题，因为它出现在代码的前面，但我不知道Android Studio中的编译器如何显示错误，所以我可能会弄错

有没有人知道是什么导致了这一切

提前谢谢

堆栈跟踪：

* Exception is:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task
':app:com
pileDebugJava'.
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.ex
ecuteActions(ExecuteActionsTaskExecuter.java:69)
at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.ex
ecute(ExecuteActionsTaskExecuter.java:46)
at org.gradle.api.internal.tasks.execution.PostExecutionAnalysisTaskExec
uter.execute(PostExecutionAnalysisTaskExecuter.java:35)
at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.exec
ute(SkipUpToDateTaskExecuter.java:64)
at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execut 
e(ValidatingTaskExecuter.java:58)
at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecu
ter.execute(SkipEmptySourceFilesTaskExecuter.java:42)
at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter
.execute(SkipTaskWithNoActionsExecuter.java:52)
at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execut
e(SkipOnlyIfTaskExecuter.java:53)
at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter
.execute(ExecuteAtMostOnceTaskExecuter.java:43)
at org.gradle.api.internal.AbstractTask.executeWithoutThrowingTaskFailur
e(AbstractTask.java:310)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorW
orker.executeTask(AbstractTaskPlanExecutor.java:79)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorW
orker.processTask(AbstractTaskPlanExecutor.java:63)
at org.gradle.execution.taskgraph.AbstractTaskPlanExecutor$TaskExecutorW
orker.run(AbstractTaskPlanExecutor.java:51)
at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor.process(Defaul
tTaskPlanExecutor.java:23)
at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter.execute(Defau
ltTaskGraphExecuter.java:88)
at org.gradle.execution.SelectedTaskExecutionAction.execute(SelectedTask
ExecutionAction.java:37)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecute
r.java:62)
at org.gradle.execution.DefaultBuildExecuter.access$200(DefaultBuildExec
uter.java:23)
at org.gradle.execution.DefaultBuildExecuter$2.proceed(DefaultBuildExecu
ter.java:68)
at org.gradle.execution.DryRunBuildExecutionAction.execute(DryRunBuildEx
ecutionAction.java:32)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecute
r.java:62)
at org.gradle.execution.DefaultBuildExecuter.execute(DefaultBuildExecute
r.java:55)
at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(Default
GradleLauncher.java:149)
at org.gradle.initialization.DefaultGradleLauncher.doBuild(DefaultGradle
Launcher.java:106)
at org.gradle.initialization.DefaultGradleLauncher.run(DefaultGradleLaun
cher.java:86)
at org.gradle.launcher.exec.InProcessBuildActionExecuter$DefaultBuildCon
troller.run(InProcessBuildActionExecuter.java:90)
at org.gradle.tooling.internal.provider.ExecuteBuildActionRunner.run(Exe
cuteBuildActionRunner.java:28)
at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildA
ctionRunner.java:35)
at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProce
ssBuildActionExecuter.java:41)
at org.gradle.launcher.exec.InProcessBuildActionExecuter.execute(InProce
ssBuildActionExecuter.java:28)
at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.exe
cute(DaemonUsageSuggestingBuildActionExecuter.java:50)
at org.gradle.launcher.exec.DaemonUsageSuggestingBuildActionExecuter.exe
cute(DaemonUsageSuggestingBuildActionExecuter.java:27)
at org.gradle.launcher.cli.RunBuildAction.run(RunBuildAction.java:40)
at org.gradle.internal.Actions$RunnableActionAdapter.execute(Actions.jav
a:169)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction. 
execute(CommandLineActionFactory.java:237)
at org.gradle.launcher.cli.CommandLineActionFactory$ParseAndBuildAction.
execute(CommandLineActionFactory.java:210)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRunti
meValidationAction.java:35)
at org.gradle.launcher.cli.JavaRuntimeValidationAction.execute(JavaRunti
meValidationAction.java:24)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(
CommandLineActionFactory.java:206)
at org.gradle.launcher.cli.CommandLineActionFactory$WithLogging.execute(
CommandLineActionFactory.java:169)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionRep
ortingAction.java:33)
at org.gradle.launcher.cli.ExceptionReportingAction.execute(ExceptionRep
ortingAction.java:22)
at org.gradle.launcher.Main.doAction(Main.java:33)
at org.gradle.launcher.bootstrap.EntryPoint.run(EntryPoint.java:45)
at org.gradle.launcher.bootstrap.ProcessBootstrap.runNoExit(ProcessBoots
trap.java:54)
at org.gradle.launcher.bootstrap.ProcessBootstrap.run(ProcessBootstrap.j
ava:35)
at org.gradle.launcher.GradleMain.main(GradleMain.java:23)
at org.gradle.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.ja
va:33)
at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:130)
at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:48)
Caused by: org.gradle.api.internal.tasks.compile.CompilationFailedException:      
Com
pilation failed; see the compiler error output for details.
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJava
Compiler.java:47)
at org.gradle.api.internal.tasks.compile.JdkJavaCompiler.execute(JdkJava
Compiler.java:33)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.delegat
eAndHandleErrors(NormalizingJavaCompiler.java:101)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute
(NormalizingJavaCompiler.java:50)
at org.gradle.api.internal.tasks.compile.NormalizingJavaCompiler.execute
(NormalizingJavaCompiler.java:36)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.exe
cute(CleaningJavaCompilerSupport.java:34)
at org.gradle.api.internal.tasks.compile.CleaningJavaCompilerSupport.exe
cute(CleaningJavaCompilerSupport.java:25)
at org.gradle.api.tasks.compile.JavaCompile.performCompilation(JavaCompi
le.java:157)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:137
)
at org.gradle.api.tasks.compile.JavaCompile.compile(JavaCompile.java:91)

at org.gradle.internal.reflect.JavaMethod.invoke(JavaMethod.java:75)
at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskF
    actory$IncrementalTaskAction.doExecute(AnnotationProcessingTaskFactory.java:243)

        at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskF
actory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:219)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskF
actory$IncrementalTaskAction.execute(AnnotationProcessingTaskFactory.java:230)
    at org.gradle.api.internal.project.taskfactory.AnnotationProcessingTaskF
    actory$StandardTaskAction.execute(AnnotationProcessingTaskFactory.java:208)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.ex
    ecuteAction(ExecuteActionsTaskExecuter.java:80)
    at org.gradle.api.internal.tasks.execution.ExecuteActionsTaskExecuter.ex
    ecuteActions(ExecuteActionsTaskExecuter.java:61)
    ... 49 more

问题似乎是“R.drawable.pointer”，你能检查一下你是否有那个文件吗？是的，我有那个文件保存在res/drawable下。在Android Studio中，当我转到该行时，它甚至会显示图片来代替行号。如果只是为了测试而使用R.drawable.bus而不是poinet，您仍然会收到一个错误？另外，你能把异常的痕迹放进去吗，也许那里有有用的信息！当我将其更改为R.drawable.bus时，没有错误，它完全构建。我在这个问题上添加了堆栈跟踪。似乎在某个时候，grade在编译项目时失败了。可能是因为找不到drawable.pointer。也许这会有帮助：