Question

Strangley，我的AsyncTask将执行onPreExecute但不会doInBackground()或onPostExecute()。 Logcat没有错误或消息表明出现了问题。

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);
    }
}

如您所见，AsycTask并不特别，但doInBackground和onPostExecute未在测试用例和Activity中都被调用。我不明白发生了什么，请让我明白什么是错的。感谢。

Answer 1

AsyncTask必须是CsLocationTaskTest的子类。此外，您不需要null。

根据开发文档：

"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).)"

发现于：http://developer.android.com/reference/android/os/AsyncTask.html

试试这个：

 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============");
    }
}


}

无法调用AsyncTask doInBackground（）和onPostExecute

1 个答案: