所以我试图点击RecyclerView项目。如果位置在视图中，那么此代码可以正常工作
onView(withId(R.id.recyclerView)).perform(
RecyclerViewActions.actionOnItemAtPosition(7, click()));
所以说如果项目不在视图中我首先执行滚动操作，然后单击它。在这种情况下，这是不必要的，因为RecyclerViewActions.actionOnItemAtPosition最初调用
new ScrollToPositionViewAction(position).perform(uiController, view);
uiController.loopMainThreadUntilIdle();
在执行实际点击操作之前。 Reference
无论如何，最终，它产生了以下异常
android.support.test.espresso.PerformException: Error performing 'single click' on view 'with id: com.abc.test.d:id/recyclerView'.
at android.support.test.espresso.PerformException$Builder.build(PerformException.java:83)
at android.support.test.espresso.base.DefaultFailureHandler.getUserFriendlyError(DefaultFailureHandler.java:70)
at android.support.test.espresso.base.DefaultFailureHandler.handle(DefaultFailureHandler.java:53)
at android.support.test.espresso.ViewInteraction.runSynchronouslyOnUiThread(ViewInteraction.java:184)
at android.support.test.espresso.ViewInteraction.doPerform(ViewInteraction.java:115)
at android.support.test.espresso.ViewInteraction.perform(ViewInteraction.java:87)
at com.abc.test.FirstScreenTest.testInteraction(FirstScreenTest.java:69)
at java.lang.reflect.Method.invoke(Native Method)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
at android.support.test.internal.statement.UiThreadStatement.evaluate(UiThreadStatement.java:55)
at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:257)
at org.junit.rules.RunRules.evaluate(RunRules.java:20)
at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runners.Suite.runChild(Suite.java:128)
at org.junit.runners.Suite.runChild(Suite.java:27)
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:54)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:240)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1879)
Caused by: android.support.test.espresso.PerformException: Error performing 'click (after 3 attempts)' on view 'unknown'.
at android.support.test.espresso.PerformException$Builder.build(PerformException.java:83)
at android.support.test.espresso.action.MotionEvents.sendDown(MotionEvents.java:111)
at android.support.test.espresso.action.Tap.sendSingleTap(Tap.java:133)
at android.support.test.espresso.action.Tap.access$100(Tap.java:35)
at android.support.test.espresso.action.Tap$1.sendTap(Tap.java:40)
at android.support.test.espresso.action.GeneralClickAction.perform(GeneralClickAction.java:98)
at android.support.test.espresso.contrib.RecyclerViewActions$ActionOnItemAtPositionViewAction.perform(RecyclerViewActions.java:303)
at android.support.test.espresso.ViewInteraction$1.run(ViewInteraction.java:144)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:423)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)