How can I refresh Fragment with ListView?

Question

SOLVED - in my comment below. My fragment contains a ListView that displays data from a database. When I press Clear, I delete data from the database. I want to instantly refresh data on screen and I think that I need to refresh my Fragment:

public class MyFragment extends Fragment implements View.OnClickListener

with ListView:

@Override
public View onCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_my, container, false);
    //...
    listView = (ListView) rootView.findViewById(R.id.listView);
    adapter = new ArrayAdapter<String>(getActivity(),R.layout.row, R.id.label, my_data);
    listView.setAdapter(adapter);

    return rootView;
    }
}

I want to call refresh here, after click on button:

@Override
    public void onClick(View v) {
        db.deleteAll();
        my_data = db.getAllData();
        adapter.notifyDataSetChanged();

        /*
         * I tried this:
           Fragment currentFragment =getFragmentManager().findFragmentByTag("MyFragment");
           FragmentTransaction fragTransaction = getFragmentManager().beginTransaction();
           fragTransaction.detach(currentFragment);
           fragTransaction.attach(currentFragment);
           fragTransaction.commit();
        */
}

I tried solution that i wrote in comment (and many similar, that i found on SO), but it crashes. Do you have any directions how can i do it?

My LogCat:

    E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.NullPointerException
    at android.app.BackStackRecord.run(BackStackRecord.java:668)
    at android.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1447)
    at android.app.FragmentManagerImpl$1.run(FragmentManager.java:443)
    at android.os.Handler.handleCallback(Handler.java:733)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:136)
    at android.app.ActivityThread.main(ActivityThread.java:5017)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:515)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
    at dalvik.system.NativeStart.main(Native Method)

post your logcat ( http://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this ) — EpicPandaForce, Sep 09 '14 at 13:17

score 0 · Answer 1 · answered Sep 09 '14 at 14:11

0

I just solve my problem, it wasn't necessary to refresh Fragment. It's enough to notify adapter about changes and and then re-set it on listView. I wanted to vote-up but I have too low reputation, so thank You especially to @Arash and @Roll no1

answered Sep 09 '14 at 14:11

livetwice

65
8

score 0 · Accepted Answer · answered Sep 09 '14 at 14:15

You don't need to refresh the fragment. Reset the adapter with the new results. Here is an example:

@Override
public void onClick(View v) {
    db.deleteAll();
    link_list = db.getAllLinks();
    adapter = new ArrayAdapter<String>(getActivity(),R.layout.row, R.id.label, link_list);
    listView.setAdapter(adapter);
}

How can I refresh Fragment with ListView?

2 Answers2