What happens to an AsyncTask when the launching activity is stopped/destroyed while it is still running?

Question

I\'ve seen few questions nearly identical to mine, but I couldn\'t find a complete answer that satisfies all my doubts.. so here I am.. Suppose that you have an activity wit

Answer 1

Consider this Task (where R.id.test refers to a valid view in my activity's layout):

public class LongTaskTest extends AsyncTask{
    private WeakReference mActivity;
    public LongTaskTest(Activity a){
        mActivity = new WeakReference(a);
    }
    @Override protected Void doInBackground(Void... params) {
        LogUtil.d("LongTaskTest.doInBackground()");
        SystemClock.sleep(5*60*1000);
        LogUtil.d("mActivity.get()==null " + (mActivity.get()==null));
        LogUtil.d("mActivity.get().findViewById(R.id.frame)==null " + (mActivity.get().findViewById(R.id.test)==null));
        return null;
    }
}

If I run this task from an Activity's onCreate like so:

public class Main extends Activity {
    @Override
    public void onCreate(Bundle state) {
        super.onCreate(state);
        setContentView(R.layout.testlayout);
        new LongTaskTest(this).execute();
        finish();
    }
}

No matter how long I sleep the background thread, my log always shows:

LongTaskTest.doInBackground()
mActivity.get()==null false
mActivity.get().findViewById(R.id.frame)==null false

Which is to say that the activity and its views appear to stay alive (even if I manually issue GCs via DDMS). If I had more time I'd look at a memory dump, but otherwise I don't really know why this is the case ... but in answer to your questions it appears that:

• Does it silently fail? No
• Does it produce any exception? No
• Will the user be notified that something has gone wrong? No