How to reset viewpager content on Android?

Question

Please tell me how to reset the content of ViewPager on android. I tried to call adapter.notifyDataSetChanged() but the adapter doesn't call getItem(position) when I scroll the view. It always returns old child views.

Update: This is my Fragment View. When I reset viewPager data, It used loaded Fragment views. It's just start at the onCreateView instead of Constructor.

public class ResultView extends Fragment {
//Declare properties

     //Constructor 
public ResultView(Province province, Calendar calendar) {
    Log.d("xskt", "ResultView constructor");
    this.province = province;
    this.calendar = (Calendar) calendar.clone();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    Log.d("xskt", "ResultView onCreateView");
    View view = inflater.inflate(R.layout.resultview, null);

    //do some thing

    return view;
}

Thanks.

Also you can try to override `public void destroyItem (ViewGroup container, int position, Object object)` `PageAdapter`'s callback to kill fragment that currently outside of the screen. Hope this will helps))) — Evos, Dec 04 '12 at 15:42
I have tried you recommend but no successful. I updated my question with more details of my case. — Nguyen Minh Binh, Dec 04 '12 at 15:57
Have you tried that solution? http://stackoverflow.com/a/7287121/1001401 — nfirex, Dec 04 '12 at 21:10
yes, I did. But the problem was not be solved. I have changed to use FragmentStatePagerAdapter rather than FragmentPagerAdapter, it works. So surprise! Thanks. — Nguyen Minh Binh, Dec 05 '12 at 02:20

Nguyen Minh Binh · Accepted Answer · 2012-12-05T07:24:07.183

39

I have changed to use FragmentStatePagerAdapter instead of FragmentPagerAdapter, the problem is resolved. Hope this helps.

edited Dec 05 '12 at 07:24

answered Dec 05 '12 at 02:21

Nguyen Minh Binh

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1

I've found a page and published it on Google+ on this. If people are interested in why this fixes it...https://plus.google.com/114575746308111414670/posts/XgVFNVMJcYM – Boy Nov 11 '13 at 18:57

score 2 · Answer 2 · edited Jan 01 '20 at 03:29

I think the best solution to reload fragments in another fragment is :

@Override
public void onPause() {
    super.onResume();
    List<Fragment> fragments = getFragmentManager().getFragments();
    if (fragments != null) {
        FragmentTransaction fragmentTransaction  = getFragmentManager().beginTransaction();
        for (Fragment fragment : fragments) {
            if (fragment instanceof Fragment) {
                fragmentTransaction.remove(fragment);
            }
        }
        fragmentTransaction.commitNowAllowingStateLoss();
    }
}

Check for your use case whether commitNowAllowingStateLoss or commitAllowingStateLoss is necessary.

score 0 · Answer 3 · answered Dec 04 '12 at 16:11

0

One method is to use the observer pattern. The data you are presenting is likely in an sqlite DB (or in stored in memory). You can set a listener in your fragment that will make the necessary updates to your fragment when the data is changed.

answered Dec 04 '12 at 16:11

Patrick Jackson

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My fragment view load data from DB base on 2 parameter I put on constructor. Please give me some example codes to do this. Thanks you so much. – Nguyen Minh Binh Dec 04 '12 at 16:18
@Patrick I would be glad to see some sample code with observer pattern that refreshes the view pager. – Rakesh Waghela Apr 04 '15 at 05:50

score 0 · Answer 4 · answered Feb 10 '21 at 15:45

It works if you do the following:

invalidate the viewPager to invalidate the cache
call notifyDataSetChanged() to tell the adapter that there have been changes and it has to refresh the Fragments
override getItemPosition in your FragmentStatePagerAdapter in order to have all of your Fragments refreshed

In your Activity or wherever you want to refresh the data:

viewPager.invalidate();
fragmentStatePageAdapter.notifyDataSetChanged();

In you FragmentStatePageAdapter:

@Override
public int getItemPosition(@NotNull Object object) {
    return POSITION_NONE;
}

How to reset viewpager content on Android?

4 Answers4

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