Question

Strangley, my AsyncTask will execute onPreExecute but not doInBackground() or onPostExecute().
Logcat has no error or message indicating that something is going wrong.

class LocationTask extends AsyncTask<String, Void, String>{

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        Log.d(TAG, "onPreExecute============");
    }

    @Override
    protected String doInBackground(String... urls) {
        Log.d(TAG, "doInBackground============");
        Log.d(TAG, "urls[0]:" + urls[0]);
        return "test";
    }

    @Override
    protected void onPostExecute(String result){
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        Log.d(TAG, "onPostExecute============");
    }
}

public class CsLocationTaskTest extends AndroidTestCase {

    public void testExecute(){
        LocationTask task = new LocationTask();
        task.execute("my_test_url", null);
    }
}

As you see, AsycTask is nothing special, but doInBackground and onPostExecute are not being called in both a test case and in my Activity. I don’t understand what happened, please let me understand what is wrong. Thanks.

Answer 1

AsyncTask needs to be a sub class of CsLocationTaskTest. Also, you don’t need null.

Per the development document:

"AsyncTask must be subclassed to be used. The subclass will override at least one method (doInBackground(Params...)), and most often will override a second one (onPostExecute(Result).)"

Found at: http://developer.android.com/reference/android/os/AsyncTask.html

Try this:

 public class CsLocationTaskTest extends AndroidTestCase {

    public void testExecute(){
        LocationTask task = new LocationTask();
        task.execute("my_test_url");
    }

    class LocationTask extends AsyncTask<String, Void, String>{

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        Log.d(TAG, "onPreExecute============");
    }

    @Override
    protected String doInBackground(String... urls) {
        Log.d(TAG, "doInBackground============");
        Log.d(TAG, "urls[0]:" + urls[0]);
        return "test";
    }

    @Override
    protected void onPostExecute(String result){
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        Log.d(TAG, "onPostExecute============");
    }
}


}