RecyclerView无法在android espresso测试上滚动

Question

我想滚动一个recyclerView并单击最初在屏幕上不可见的项目（使用Espresso，但是滚动操作不起作用（在其他活动中的其他recyclerViews的其他测试中确实如此）。

我已经尝试过https://developer.android.com/training/testing/espresso/lists中指示的onData（）方法>

但是它也不能正常工作。

这是我执行滚动并单击：]的方法

fun scrollToPositionAndClick(resId: Int, position: Int) {
        getActivityInstance()?.findViewById<RecyclerView>(resId)?.adapter?.let {
            onView(withId(resId))
                .perform(
                    scrollToPosition<RecyclerView.ViewHolder>(position),
                    actionOnItemAtPosition<RecyclerView.ViewHolder>(position, click())
                )
        }
    }
此方法在其他活动测试中有效，但由于某种原因，不适用于此屏幕（碎片），并且出现此错误：
androidx.test.espresso.PerformException: Error performing 'single click - At Coordinates: 290, 2197 and precision: 16, 16'
...
Caused by: androidx.test.espresso.PerformException: Error performing 'click (after 3 attempts)' on view 'unknown'.
我想滚动一个recyclerView并单击最初在屏幕上看不到的Espresso，但滚动动作不起作用（它在其他测试中确实适用于... 
当我在ViewPager中有一个RecyclerView时，我没有滚动问题。我能够通过自己执行RecyclerViewAction.scrollToPosition来修复它。我没有使用recyclerView滚动条的API，而是使用LayoutManager的API，如果它是LinearLayoutManager，则使用了scrollToPositionWithOffset。 
这里是该操作的代码。除了perform方法之外，其他都与原始文档相同。
public final class CustomRecyclerViewActions {

private CustomRecyclerViewActions() { }


public static <VH extends RecyclerView.ViewHolder> ViewAction scrollToPosition(@IntRange(from = 0) final int position) {
   return new ScrollToPositionViewAction(position);
}

private static final class ScrollToPositionViewAction implements ViewAction {
   private final int position;

   private ScrollToPositionViewAction(int position) {
     this.position = position;
   }

   public Matcher<View> getConstraints() {
      return Matchers.allOf(ViewMatchers.isAssignableFrom(RecyclerView.class), ViewMatchers.isDisplayed());
   }

  public String getDescription() {
    int var1 = this.position;
    return (new StringBuilder(44)).append("scroll RecyclerView to position: ").append(var1).toString();
  }

  public void perform(@NonNull UiController uiController, @NonNull View view) {
    RecyclerView recyclerView = (RecyclerView)view;
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    if (layoutManager instanceof LinearLayoutManager) {
      ((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(this.position, 0);
    } else {
      layoutManager.scrollToPosition(this.position);
    }
    uiController.loopMainThreadUntilIdle();
   }
 }
}

Answer 1

当我在ViewPager中有一个RecyclerView时，我没有滚动问题。我能够通过自己执行RecyclerViewAction.scrollToPosition来修复它。我没有使用recyclerView滚动条的API，而是使用LayoutManager的API，如果它是LinearLayoutManager，则使用了scrollToPositionWithOffset。

这里是该操作的代码。除了perform方法之外，其他都与原始文档相同。

public final class CustomRecyclerViewActions {

private CustomRecyclerViewActions() { }


public static <VH extends RecyclerView.ViewHolder> ViewAction scrollToPosition(@IntRange(from = 0) final int position) {
   return new ScrollToPositionViewAction(position);
}

private static final class ScrollToPositionViewAction implements ViewAction {
   private final int position;

   private ScrollToPositionViewAction(int position) {
     this.position = position;
   }

   public Matcher<View> getConstraints() {
      return Matchers.allOf(ViewMatchers.isAssignableFrom(RecyclerView.class), ViewMatchers.isDisplayed());
   }

  public String getDescription() {
    int var1 = this.position;
    return (new StringBuilder(44)).append("scroll RecyclerView to position: ").append(var1).toString();
  }

  public void perform(@NonNull UiController uiController, @NonNull View view) {
    RecyclerView recyclerView = (RecyclerView)view;
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    if (layoutManager instanceof LinearLayoutManager) {
      ((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(this.position, 0);
    } else {
      layoutManager.scrollToPosition(this.position);
    }
    uiController.loopMainThreadUntilIdle();
   }
 }
}