問題描述

在我的測試中，我有一個階段，在按下按鈕后，應用程序會執行大量異步計算并向云服務發出請求，之后它會顯示某個視圖.

In my test I have a stage where after pressing a button application does a lot of asynchronous calculations and requests to the cloud service, after which it displays a certain view.

是否可以使用 Espresso 的 IdlingResource 實現等到某個視圖出現?

Is it possible to use Espresso's IdlingResource implementation to wait until a certain view appears?

我已閱讀此處的答案，并且評論似乎表明您可以使用 IdlingResource 代替，但我不明白如何.Espresso 似乎沒有任何內置方法來處理長操作，但必須編寫自己的等待循環感覺就像是 hack.

I've read an answers here and comments seems to suggest that you can use IdlingResource instead, but I don't understand how. Espresso does not seem to have any built-in way to handle long operations, but having to write your own waiting loops feels like a hack.

有什么方法可以解決這個問題，或者我應該按照鏈接線程中的答案建議做嗎?

Any way to solve this or should I just do as the answer in the linked thread suggests?

推薦答案

您的 IdlingResource 可能如下所示:

Your IdlingResource could look like this:

import android.support.test.espresso.IdlingResource;
import android.support.test.espresso.ViewFinder;
import android.support.test.espresso.ViewInteraction;
import android.view.View;

import org.hamcrest.Matcher;

import java.lang.reflect.Field;

import static android.support.test.espresso.Espresso.onView;

public class ViewShownIdlingResource implements IdlingResource {

    private static final String TAG = ViewShownIdlingResource.class.getSimpleName();

    private final Matcher<View> viewMatcher;
    private ResourceCallback resourceCallback;

    public ViewShownIdlingResource(final Matcher<View> viewMatcher) {
        this.viewMatcher = viewMatcher;
    }

    @Override
    public boolean isIdleNow() {
        View view = getView(viewMatcher);
        boolean idle = view == null || view.isShown();

        if (idle && resourceCallback != null) {
            resourceCallback.onTransitionToIdle();
        }

        return idle;
    }

    @Override
    public void registerIdleTransitionCallback(ResourceCallback resourceCallback) {
        this.resourceCallback = resourceCallback;
    }

    @Override
    public String getName() {
        return this + viewMatcher.toString();
    }

    private static View getView(Matcher<View> viewMatcher) {
        try {
            ViewInteraction viewInteraction = onView(viewMatcher);
            Field finderField = viewInteraction.getClass().getDeclaredField("viewFinder");
            finderField.setAccessible(true);
            ViewFinder finder = (ViewFinder) finderField.get(viewInteraction);
            return finder.getView();
        } catch (Exception e) {
            return null;
        }
    }
}

然后，您可以創建一個等待您的視圖的輔助方法:

Then, you could create a helper method waiting for your view:

public void waitViewShown(Matcher<View> matcher) {
    IdlingResource idlingResource = new ViewShownIdlingResource(matcher);///
    try {
        IdlingRegistry.getInstance().register(idlingResource);
        onView(matcher).check(matches(isDisplayed()));  
    } finally {
        IdlingRegistry.getInstance().unregister(idlingResource);
    }    
}

最后，在你的測試中:

@Test
public void someTest() {
    waitViewShown(withId(R.id.<some>));

    //do whatever verification needed afterwards    
} 

您可以通過讓 IdlingResource 等待任何條件來改進此示例，而不僅僅是等待可見性條件.

You could improve this example by making IdlingResource wait for any condition, not just for the visibility one.

這篇關于是否可以使用 Espresso 的 IdlingResource 等到某個視圖出現?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！