CODEWITHSUNDEEP
androidandroid-fragmentsandroid-adapterandroid-recyclerview
fragon
fragon

Reputation: 3471

notifyDataSetChanged() doesn't work with my custom adapter

I've created a simple RecyclerView.Adapter and it displays the content properly, but when I call notifyDataSetChanged() on it - it doesn't work.

PastEventFragment 

public class PastEventFragment extends Fragment {
    private RecyclerView mRecyclerView;
    private List<PastEventItem> mPastEventItemList;
    private PastEventAdapter mPastEventAdapter;

    public PastEventFragment() {

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        super.onCreateView(inflater, container, savedInstanceState);
        View pastEvent = inflater.inflate(R.layout.fragment_past_event, container, false);
        mRecyclerView = (RecyclerView) pastEvent.findViewById(R.id.pe_rv);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
        mPastEventItemList = PastEventItem.listAll(PastEventItem.class);
        mPastEventAdapter = new PastEventAdapter(mPastEventItemList, getActivity());
        mRecyclerView.setAdapter(mPastEventAdapter);

        return pastEvent;
    }

    public void refreshAdapter() {
        mPastEventItemList.clear();
        mPastEventItemList = PastEventItem.listAll(PastEventItem.class);
        mPastEventAdapter.notifyDataSetChanged();
    }



}

Adapter:

public class PastEventAdapter extends RecyclerView.Adapter<PastEventAdapter.PastEventHolder> {

    private List<PastEventItem> pastEventItemList;
    private Context mContext;

    public PastEventAdapter(List<PastEventItem> pastEventItemList, Context context) {
        this.pastEventItemList = pastEventItemList;
        this.mContext = context;
    }


    @Override
    public int getItemCount() {
        return pastEventItemList.size();
    }

    @Override
    public void onBindViewHolder(PastEventHolder pastEventHolder, int i) {
        PastEventItem pei = pastEventItemList.get(i);
        switch (pei.type) {
            case 1:
                pastEventHolder.type.setText(mContext.getResources().getString(R.string.string1));
                break;
            case 2:
                pastEventHolder.type.setText(mContext.getResources().getString(R.string.string2));
                break;
            case 3:
                pastEventHolder.type.setText(mContext.getResources().getString(R.string.string3));
                break;
            case 4:
                pastEventHolder.type.setText(mContext.getResources().getString(R.string.string4));
                break;
        }

        pastEventHolder.ml.setText(Integer.toString(pei.ml));
        pastEventHolder.per.setText(Integer.toString(pei.per));
    }

    @Override
    public PastEventHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View itemView = LayoutInflater.
                from(viewGroup.getContext()).
                inflate(R.layout.past_event_item, viewGroup, false);

        return new PastEventHolder(itemView);
    }


    public static class PastEventHolder extends RecyclerView.ViewHolder {
        private TextView type;
        private TextView ml;
        private TextView per;

        public PastEventHolder(View v) {
            super(v);
            type = (TextView) v.findViewById(R.id.pe_type);
            ml = (TextView) v.findViewById(R.id.pe_ml);
            per = (TextView) v.findViewById(R.id.pe_per);
        }
    }
}

I call refreshAdapter method from another Fragment (DialogFragment) through an Activity, using Interface. I used a debugger, so I know that the refreshAdapter method is called. It just has no impact on the RecyclerView which is displayed. When I leave the PastEventFragment and then switch back to it, so that the onCreateView method is called, all previously added items are shown, so there is no problem with the ORM.

Upvotes: 2

Views: 845

Answers (2)

sockeqwe
sockeqwe

Reputation: 15929

Your adapter has a reference to mPastEventItemList. However, you are creating a new List (a new reference) in this line of code:

mPastEventItemList = PastEventItem.listAll(PastEventItem.class);

but your adapter is still connected to the old reference of mPastEventItemList.

So you should do something like that instead:

 public void refreshAdapter() {
        mPastEventItemList.clear();
        mPastEventItemList.addAll(PastEventItem.listAll(PastEventItem.class));
        mPastEventAdapter.notifyDataSetChanged();
    }

Upvotes: 2

Surely
Surely

Reputation: 1709

Try to add a setItemList() method in the adapter. And set the updated list data using this method with the adapter, after this, call the notifyDatasetChange method

Upvotes: 0

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