我正在得到
android.support.test.espresso.PerformException：执行'发送错误在“动画或过渡”视图上显示keyCode：4，metaState：0键事件在目标设备上启用。
我阅读了同样的错误但没有找到答案的文章。
我有一个简单的android应用，我尝试测试简单的东西：
代码非常容易：
@Test
public void getOver500Products() {
onView(withId(R.id.drawer_layout)).perform(DrawerActions.open());
onView(withId(R.id.layout2)).perform(click());
clickExactItem(2);
for (int i = 0; i< 501; i++) {
clickRandomItem();
addedToCart();
Espresso.pressBack();
}
}
public void clickRandomItem() {
try {
int x = getRandomRecyclerPosition(R.id.list);
clickExactItem(x);
} catch (NoMatchingViewException e) {
}
}
public void clickExactItem(int position) {
onView(withId(R.id.list))
.perform(RecyclerViewActions
.actionOnItemAtPosition(position, click()));
}
public boolean addedToCart() {
try {
onView(withId(R.id.product_add_in_cart)).perform(click());
} catch (NoMatchingViewException e) {
return false;
}
return true;
}
[它在10-50次迭代后（随机）抛出异常，因此基本上代码是正确的。
EspressoTestDev.java:88崩溃所在的行是
Espresso.pressBack();
恰好在此行之后，我得到了例外。
Exception stacktrace：
android.support.test.espresso.PerformException: Error performing 'send keyCode: 4, metaState: 0 key event' on view 'Animations or transitions are enabled on the target device.
is a root view.'.
at android.support.test.espresso.PerformException$Builder.build(PerformException.java:83)
at android.support.test.espresso.base.DefaultFailureHandler.getUserFriendlyError(DefaultFailureHandler.java:80)
at android.support.test.espresso.base.DefaultFailureHandler.handle(DefaultFailureHandler.java:56)
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 android.support.test.espresso.Espresso.pressBack(Espresso.java:189)
at com.app.myapp.EspressoTestDev.getOver500Products(EspressoTestDev.java:88)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
at android.support.test.internal.statement.UiThreadStatement.evaluate(UiThreadStatement.java:55)
at android.support.test.rule.ActivityTestRule$ActivityStatement.evaluate(ActivityTestRule.java:270)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at org.junit.runner.JUnitCore.run(JUnitCore.java:115)
at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1851)
Caused by: java.lang.RuntimeException: Action will not be performed because the target view does not match one or more of the following constraints:
is displayed on the screen to the user
Target view: "PopupViewContainer{id=-1, visibility=VISIBLE, width=0, height=0, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=false, is-enabled=true, is-focused=false, is-focusable=false, is-layout-requested=false, is-selected=false, root-is-layout-requested=false, has-input-connection=false, x=0.0, y=0.0, child-count=1}"
at android.support.test.espresso.ViewInteraction$1.run(ViewInteraction.java:138)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:422)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.Handler.handleCallback(Handler.java:815)
at android.os.Handler.dispatchMessage(Handler.java:104)
at android.os.Looper.loop(Looper.java:194)
at android.app.ActivityThread.main(ActivityThread.java:5549)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:964)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:759)
看起来它发现PopupViewContainer有问题，但我没有使用它，也没有单击它，我也不知道它如何影响Espresso.pressBack()
我尝试过的事情：
在getInstrumentation().waitForIdleSync();之前和之后添加Espresso.pressBack()] >>
根据建议设置延迟here
问题是：如何避免
我正在获取android.support.test.espresso.PerformException：在视图'执行目标设备上的动画或过渡时执行'发送keyCode：4，metaState：0键事件'时出错。我...
在目标设备上启用了动画或过渡。
从控制台，则必须添加以下命令：
onView(...).perform(scrollTo(), click());
Animations or transitions are enabled on the target device。在最新情况下，真正的问题是我的UI代码抛出了NullPointerException。不幸的是，Espresso误吞了NullPointerException，并给了我无关的错误Animations or transitions are enabled on the target device。Alternativ通过代码将500个项目添加到购物车，然后通过UI测试添加1个额外项目。