android - Espresso onView 不等待元素

Question

我刚开始使用 Espresso recorder .我进行了第一次测试，从我可以看到的功能 onView ，这是假设等待对象继续不做的工作。它总是返回:
android.support.test.espresso.NoMatchingViewException: No views in hierarchy found matching .

是否有任何功能可以用作 wait for我可以改用吗？

package com.mytest;


import android.support.test.espresso.ViewInteraction;
import android.support.test.rule.ActivityTestRule;
import android.support.test.runner.AndroidJUnit4;
import android.test.suitebuilder.annotation.LargeTest;
import android.support.test.espresso.Espresso;
import android.support.test.espresso.IdlingResource;



import org.junit.Rule;
import org.junit.Test;
import org.junit.Before;
import org.junit.runner.RunWith;

import com.mytest.R;



import static android.support.test.espresso.Espresso.onView;
import static android.support.test.espresso.action.ViewActions.click;
import static android.support.test.espresso.contrib.RecyclerViewActions.actionOnItemAtPosition;
import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
import static android.support.test.espresso.matcher.ViewMatchers.withId;
import static android.support.test.espresso.matcher.ViewMatchers.withParent;
import static org.hamcrest.Matchers.allOf;

@LargeTest
@RunWith(AndroidJUnit4.class)
public class Test1 {

    @Rule
    public ActivityTestRule<MainActivity> mActivityRule = new ActivityTestRule<>(MainActivity.class);

    private IdlingResource mIdlingResource;

    @Before
    public void registerIdlingResource() {
        mIdlingResource = mActivityRule.getActivity().getIdlingResource();
        Espresso.registerIdlingResources(mIdlingResource);
    }

    @Test
    public void test1() {
        ViewInteraction recyclerView = onView(
                allOf(withId(R.id.recycler_view), isDisplayed()));
        recyclerView.perform(actionOnItemAtPosition(0, click()));

        ViewInteraction relativeLayout = onView(
                allOf(withId(R.id.capture_layout), isDisplayed()));
        relativeLayout.perform(click());

        ViewInteraction relativeLayout2 = onView(
                allOf(withId(R.id.like_layout),
                        withParent(allOf(withId(R.id.cameraLayout),
                                withParent(withId(android.R.id.content)))),
                        isDisplayed()));
        relativeLayout2.perform(click());

        ViewInteraction relativeLayout3 = onView(
                allOf(withId(R.id.exit_layout), isDisplayed()));
        relativeLayout3.perform(click());

    }
}

Answer 1

一种方法是与匹配器循环直到它发生。当我需要等待异步任务完成时，我使用以下帮助程序。

public class ViewSynchronizer {
    private static final String TAG = "MC_Synchronizer";

    public static boolean viewExists(final Matcher<View> viewMatcher, final long millis) throws InterruptedException {
        final Boolean[] found = new Boolean[1];

        final CountDownLatch latch = new CountDownLatch(1);
        ViewAction action = new ViewAction() {
            @Override
            public Matcher<View> getConstraints() {
                return isRoot();
            }

            @Override
            public String getDescription() {
                return "wait for a specific view with id <" + viewMatcher.toString() + "> during " + millis + " millis.";
            }

            @Override
            public void perform(final UiController uiController, final View view) {
                uiController.loopMainThreadUntilIdle();
                final long startTime = System.currentTimeMillis();
                final long endTime = startTime + millis;


                do {
                    for (View child : TreeIterables.breadthFirstViewTraversal(view)) {

                        if (viewMatcher.matches(child)) {
                            Log.d(TAG, "perform: found match");
                            found[0] = true;
                            latch.countDown();
                            return;
                        }
                    }

                    uiController.loopMainThreadForAtLeast(50);
                }
                while (System.currentTimeMillis() < endTime);

                found[0] = false;
                latch.countDown();
            }
        };
        onView(isRoot()).perform(action);

        latch.await();
        return found[0];
    }
}

用法:

 Assert.assertTrue(viewExists(allOf(withId(R.id.account_sign_out_btb),withEffectiveVisibility(ViewMatchers.Visibility.GONE)),2000)); //wait 2 seconds