PerformException：执行“单击”时出错

当我运行 android espresso 测试时出现错误：

com.google.android.apps.common.testing.ui.espresso.PerformException：在视图“id：为 ”上执行“单击”时出错。

我的代码很简单：

onView(withId(R.id.btn)).perform(click());

但这段代码没有错误：

onView(withId(R.id.btn)).check(matches(isDisplayed()));

我找不到发生这种情况的原因。

诀窍是读取错误的完整堆栈跟踪。中间有一些关键信息，如下所示：

Caused by: java.lang.RuntimeException: Action will not be performed because the target view does not match one or more of the following constraints:
at least 90 percent of the view's area is displayed to the user.
Target view: "ImageView{id=2131492903, res-name=button_hamburger, desc=opens the side drawer, visibility=VISIBLE, width=64, height=64, has-focus=false, has-focusable=false, has-window-focus=true, is-clickable=true, 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=6.0, y=6.0}"

这详细解释了错误。