How to cancel AsyncTask in Fragment

Question

I have created an Android Application, in that I want to cancel AsyncTask onPause state of Fragment.

I tried using AsyncTask.cancel(true); but it gives null pointer exception.

@Override
public void onPause()
{
    super.onPause();
    AsyncTask.cancel(true);
}

Thanks.

you need object of AsyncTask instead of AsyncTask class, see this for more info http://stackoverflow.com/questions/6039158/android-cancel-async-task — Shayan Pourvatan, Dec 21 '14 at 12:36
I have created the object of it, but still gives null pointer error. — Sagar Zala, Dec 21 '14 at 12:49
check object, maybe you not initialized that, check if it's not null then cancel tht — Shayan Pourvatan, Dec 21 '14 at 12:53
correct and safe way to cancel an asynctask http://www.quicktips.in/correct-way-to-cancel-an-asynctask-in-android/ — Deepak Swami, Jun 29 '16 at 17:09

score 0 · Answer 1 · answered Dec 21 '14 at 12:34

0

task.cancel() will do it. Be sure to include frequent checks to isCancelled() in your onBackground() as well as in onPostExecute() to avoid accessing/updating UI which is no longer there.

public void onActivityPause() {
    task.cancel();
}

answered Dec 21 '14 at 12:34

Shailendra Madda

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score 0 · Answer 2 · answered Dec 21 '14 at 12:45

asyncTask.cancel(true); will change a boolean value only and don't stop your thread. so you need to "ask" if the async task not cancelled.

example:

@Override
protected Void doInBackground(Void... params) {
    while(!isCancelled()){
        // do something
    }
    return null;
}

How to cancel AsyncTask in Fragment

2 Answers2