Android的AsyncTask的测试与Android测试框架 [英] Android AsyncTask testing with Android Test Framework

问题描述

我有一个非常简单的AsyncTask实现的例子，有问题，使用的是Android JUnit框架进行测试。 它工作得很好，当我实例在正常的应用程序执行。 然而，当它从任何Android的测试框架类的执行（即 AndroidTestCase 的 ActivityUnitTestCase 的 ActivityInstrumentationTestCase2 的等），它行为异常： - 它执行正确的 doInBackground（）的方法 - 然而，它没有调用它的任何通知方式（ onPostExecute（）的 onProgressUpdate（）的，等等） - 只是默默忽略它们没有显示出任何错误

I have a very simple AsyncTask implementation example and have problem to test it using Android JUnit framework. It works just fine when I instantiate and execute it in normal application. However when it's executed from any of Android Testing framework classes (i.e. AndroidTestCase, ActivityUnitTestCase, ActivityInstrumentationTestCase2 etc) it behaves strangely: - It executes doInBackground() method correctly - However it doesn't invokes any of its notification methods (onPostExecute(), onProgressUpdate(), etc) -- just silently ignores them without showing any errors.

这是很简单的AsyncTask的例子

This is very simple AsyncTask example

package kroz.andcookbook.threads.asynctask;

import android.os.AsyncTask;
import android.util.Log;
import android.widget.ProgressBar;
import android.widget.Toast;

public class AsyncTaskDemo extends AsyncTask<Integer, Integer, String> {

AsyncTaskDemoActivity _parentActivity;
int _counter;
int _maxCount;

public AsyncTaskDemo(AsyncTaskDemoActivity asyncTaskDemoActivity) {
    _parentActivity = asyncTaskDemoActivity;
}

@Override
protected void onPreExecute() {
    super.onPreExecute();
    _parentActivity._progressBar.setVisibility(ProgressBar.VISIBLE);
    _parentActivity._progressBar.invalidate();
}

@Override
protected String doInBackground(Integer... params) {
    _maxCount = params[0];
    for (_counter = 0; _counter <= _maxCount; _counter++) {
        try {
            Thread.sleep(1000);
            publishProgress(_counter);
        } catch (InterruptedException e) {
            // Ignore           
        }
    }
}

@Override
protected void onProgressUpdate(Integer... values) {
    super.onProgressUpdate(values);
    int progress = values[0];
    String progressStr = "Counting " + progress + " out of " + _maxCount;
    _parentActivity._textView.setText(progressStr);
    _parentActivity._textView.invalidate();
}

@Override
protected void onPostExecute(String result) {
    super.onPostExecute(result);
    _parentActivity._progressBar.setVisibility(ProgressBar.INVISIBLE);
    _parentActivity._progressBar.invalidate();
}

@Override
protected void onCancelled() {
    super.onCancelled();
    _parentActivity._textView.setText("Request to cancel AsyncTask");
}

}

这是一个测试案例。这里的 AsyncTaskDemoActivity 的是一个非常简单的活动在模式下进行测试的AsyncTask提供用户界面：

This is a test case. Here AsyncTaskDemoActivity is a very simple Activity providing UI for testing AsyncTask in mode:

package kroz.andcookbook.test.threads.asynctask;
import java.util.concurrent.ExecutionException;
import kroz.andcookbook.R;
import kroz.andcookbook.threads.asynctask.AsyncTaskDemo;
import kroz.andcookbook.threads.asynctask.AsyncTaskDemoActivity;
import android.content.Intent;
import android.test.ActivityUnitTestCase;
import android.widget.Button;

public class AsyncTaskDemoTest2 extends ActivityUnitTestCase<AsyncTaskDemoActivity> {
AsyncTaskDemo _atask;
private Intent _startIntent;

public AsyncTaskDemoTest2() {
    super(AsyncTaskDemoActivity.class);
}

protected void setUp() throws Exception {
    super.setUp();
    _startIntent = new Intent(Intent.ACTION_MAIN);
}

protected void tearDown() throws Exception {
    super.tearDown();
}

public final void testExecute() {
    startActivity(_startIntent, null, null);
    Button btnStart = (Button) getActivity().findViewById(R.id.Button01);
    btnStart.performClick();
    assertNotNull(getActivity());
}

}

这一切，code为工作得很好，但事实上，AsyncTask的不调用它的通知方法通过在Android的测试框架时执行。任何想法？

All this code is working just fine, except the fact that AsyncTask doesn't invoke it's notification methods when executed by within Android Testing Framework. Any ideas?

推荐答案

我遇到了类似的问题，同时实施一些单元测试。我不得不测试它与执行人工作过的一些服务，我需要让我的服务回调同步编辑从我ApplicationTestCase类的测试方法。一般测试方法本身的回调之前完成将被访问，所以通过回调发送的数据将不被测试。尝试应用@UiThreadTest胸围仍然没有奏效。

I met a similar problem while implementing some unit-test. I had to test some service which worked with Executors, and I needed to have my service callbacks sync-ed with the test methods from my ApplicationTestCase classes. Usually the test method itself finished before the callback would be accessed, so the data sent via the callbacks would not be tested. Tried applying the @UiThreadTest bust still didn't work.

我发现下面的方法，它的工作，我仍然使用它。我简单地使用CountDownLatch信号对象来实现的等待通知。（你可以使用同步（锁定）{... lock.notify（）;}，但是这会导致丑陋的code）机制

I found the following method, which worked, and I still use it. I simply use CountDownLatch signal objects to implement the wait-notify (you can use synchronized(lock){... lock.notify();}, however this results in ugly code) mechanism.

public void testSomething(){
final CountDownLatch signal = new CountDownLatch(1);
Service.doSomething(new Callback() {

  @Override
  public void onResponse(){
    // test response data
    // assertEquals(..
    // assertTrue(..
    // etc
    signal.countDown();// notify the count down latch
  }

});
signal.await();// wait for callback
}

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