Refreshing custom List withing AsyncTask android

Question

I have a custom List which I want to refresh when a action bar button is clicked. This List is within a Fragment.

I want to show a ProgressBar until the List is refreshed.

Currently Iam doing this:-

private class RefreshList extends AsyncTask<Void, Void, Void>
{

    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);

        if(refDialog!=null)
        {
            refDialog.dismiss();
        }
    }

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();

        if(refDialog!=null)
        {
            refDialog =null;
        }
        refDialog =  WaitProgressFragment.newInstance();

        refDialog.show(getFragmentManager(), "Wait");


    }

    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub
        //stagAdaper.notifyDataSetChanged();

        itemsAdapter.notifyDataSetChanged();



        return null;
    }

}

But I get this error

Caused by: android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.

How can I refresh the List while showing the progress dialog?

Check: http://stackoverflow.com/questions/5161951/android-only-the-original-thread-that-created-a-view-hierarchy-can-touch-its-vi — Paresh Mayani, Jul 15 '14 at 11:20

score 0 · Accepted Answer · answered Jul 15 '14 at 10:35

0

Put

itemsAdapter.notifyDataSetChanged();

Inside onPostExecute.

notifyDataSetChanged is an UI operation and doInBackground does not work on UI thread, whereas onPostExecute does.

answered Jul 15 '14 at 10:35

vipul mittal

17,343
3
41
44

I tried doing it, but then the ProgressDialog does not show – user3146095 Jul 15 '14 at 10:38
You need to do something in doInBackground. If you are only testing progress dialog put a sleep in doInBackground. – vipul mittal Jul 15 '14 at 10:39

score 0 · Answer 2 · answered Jul 15 '14 at 10:35

0

You have to move the portion of the background task to the UI thread,so notify itemsAdapter in onPostExecute method as

  @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        itemsAdapter.notifyDataSetChanged()

        if(refDialog!=null)
        {
            refDialog.dismiss();
        }
    }

answered Jul 15 '14 at 10:35

Giru Bhai

14,370
5
46
74

I tried doing it. But then the ProgressDialog does not show – user3146095 Jul 15 '14 at 10:37
@user3146095 call itemsAdapter.notifyDataSetChanged() before dismissing dialog,see edited answer. – Giru Bhai Jul 15 '14 at 10:38

Refreshing custom List withing AsyncTask android

2 Answers2