notifyDataSetChanged not working on RecyclerView
android, android-5.0-lollipop, android-recyclerview
Solution
In your `parseResponse()` you are creating a new instance of the `BusinessAdapter` class, but you aren't actually using it anywhere, so your `RecyclerView` doesn't know the new instance exists.
You either need to:
- Call `recyclerView.setAdapter(mBusinessAdapter)` again to update the RecyclerView's adapter reference to point to your new one
- Or just remove `mBusinessAdapter = new BusinessAdapter(mBusinesses);` to continue using the existing adapter. Since you haven't changed the `mBusinesses` reference, the adapter will still use that array list and should update correctly when you call `notifyDataSetChanged()`.
Problem
I am getting data from server and then parsing it and storing it in a List. I am using this list for the RecyclerView's adapter. I am using Fragments. I am using a Nexus 5 with KitKat. I am using support library for this. Will this make a difference? Here is my code: (Using dummy data for the question) Member Variables: ``` List<Business> mBusinesses = new ArrayList<Business>(); RecyclerView recyclerView; RecyclerView.LayoutManager mLayoutManager; BusinessAdapter mBusinessAdapter; ``` My `onCreateView()`: ``` @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Getting data from server getBusinessesDataFromServer(); View view = inflater.inflate(R.layout.fragment_business_list, container, false); recyclerView = (RecyclerView) view .findViewById(R.id.business_recycler_view); recyclerView.setHasFixedSize(true); mLayoutManager = new LinearLayoutManager(getActivity()); recyclerView.setLayoutManager(mLayoutManager); mBusinessAdapter = new BusinessAdapter(mBusinesses); recyclerView.setAdapter(mBusinessAdapter); return view; } ``` After getting data from server, `parseResponse()` is called. ``` protected void parseResponse(JSONArray response, String url) { // insert dummy data for demo mBusinesses.clear(); Business business; business = new Business(); business.setName("Google"); business.setDescription("Google HeadQuaters"); mBusinesses.add(business); business = new Business(); business.setName("Yahoo"); business.setDescription("Yahoo HeadQuaters"); mBusinesses.add(business); business = new Business(); business.setName("Microsoft"); business.setDescription("Microsoft HeadQuaters"); mBusinesses.add(business); Log.d(Const.DEBUG, "Dummy Data Inserted\nBusinesses Length: " + mBusinesses.size()); mBusinessAdapter = new BusinessAdapter(mBusinesses); mBusinessAdapter.notifyDataSetChanged(); } ``` My BusinessAdapter: ``` public class BusinessAdapter extends RecyclerView.Adapter<BusinessAdapter.ViewHolder> { private List<Business> mBusinesses = new ArrayList<Business>(); // Provide a reference to the type of views that you are using // (custom viewholder) public static class ViewHolder extends RecyclerView.ViewHolder { public TextView mTextViewName; public TextView mTextViewDescription; public ImageView mImageViewLogo; public ViewHolder(View v) { super(v); mTextViewName = (TextView) v .findViewById(R.id.textView_company_name); mTextViewDescription = (TextView) v .findViewById(R.id.textView_company_description); mImageViewLogo = (ImageView) v .findViewById(R.id.imageView_company_logo); } } // Provide a suitable constructor (depends on the kind of dataset) public BusinessAdapter(List<Business> myBusinesses) { Log.d(Const.DEBUG, "BusinessAdapter -> constructor"); mBusinesses = myBusinesses; } // Create new views (invoked by the layout manager) @Override public BusinessAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { Log.d(Const.DEBUG, "BusinessAdapter -> onCreateViewHolder()"); // create a new view View v = LayoutInflater.from(parent.getContext()).inflate( R.layout.item_business_list, parent, false); ViewHolder vh = new ViewHolder(v); return vh; } // Replace the contents of a view (invoked by the layout manager) @Override public void onBindViewHolder(ViewHolder holder, int position) { // - get element from your dataset at this position // - replace the contents of the view with that element Log.d(Const.DEBUG, "BusinessAdapter -> onBindViewHolder()"); Business item = mBusinesses.get(position); holder.mTextViewName.setText(item.getName()); holder.mTextViewDescription.setText(item.getDescription()); holder.mImageViewLogo.setImageResource(R.drawable.ic_launcher); } // Return the size of your dataset (invoked by the layout manager) @Override public int getItemCount() { Log.d(Const.DEBUG, "BusinessAdapter -> getItemCount()"); if (mBusinesses != null) { Log.d(Const.DEBUG, "mBusinesses Count: " + mBusinesses.size()); return mBusinesses.size(); } return 0; } } ``` But I don't get the data displayed in the view. What am I doing wrong? Here is my log, ``` 07-14 21:15:35.669: D/xxx(2259): Dummy Data Inserted 07-14 21:15:35.669: D/xxx(2259): Businesses Length: 3 07-14 21:26:26.969: D/xxx(2732): BusinessAdapter -> constructor ``` I don't get any logs after this. Shouldn't `getItemCount()` in adapter should be called again?