Delete item in RecyclerView- Android

Question

I ran into a problem, I was not able to delete the item in RecyclerView. I am trying to search the Internet, but I don’t see any solution. I am following this Android RecyclerView message adding and removing elements But I still could not delete the selected element Below is my code for my adapter and fragement

RecyclerViewAdapter.java

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> { List<VideoDetails> contents2; Context mContext; ImageLoader imageLoader; static final int TYPE_HEADER = 0; static final int TYPE_CELL = 1; public RecyclerViewAdapter(List<VideoDetails> contents) { this.contents2 = contents; } public RecyclerViewAdapter(Context context, List<VideoDetails> contents) { mContext = context; this.contents2 = contents; imageLoader = new ImageLoader(context); } @Override public int getItemViewType(int position) { return position; } @Override public int getItemCount() { return contents2.size(); } @Override public RecyclerViewAdapter.ViewHolder onCreateViewHolder(final ViewGroup parent, final int viewType) { View view = null; view = LayoutInflater.from(parent.getContext()) .inflate(R.layout.list_item_card_small2, parent, false); ViewHolder vh = new ViewHolder(view); return vh; } @Override public void onBindViewHolder(ViewHolder holder,final int position) { holder.title.setText(contents2.get(position).getTitle()); holder.image.setOnClickListener(new View.OnClickListener(){ @Override public void onClick(View view) { Log.d("thien.van","on Click onBindViewHolder"); contents2.remove(position); notifyItemRemoved(position); notifyItemRangeChanged(position, contents2.size()); } }); } public Bitmap getThumbnail(String str) { Bitmap bMap = ThumbnailUtils.createVideoThumbnail(str, MediaStore.Video.Thumbnails.MINI_KIND); return bMap; } public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener { public TextView title; public ImageView image; public ProgressBar progressBar; public ViewHolder(View itemView) { super(itemView); title = (TextView) itemView.findViewById(R.id.title); image = (ImageView) itemView.findViewById(R.id.thumbnail); progressBar = (ProgressBar) itemView.findViewById(R.id.progress); // image.setOnClickListener(this); } @Override public void onClick(View view) { Log.d("thien.van","onClick getAdapterPosition () = "+getAdapterPosition()); removeAt(getAdapterPosition()); } } public void removeAt(int position) { contents2.remove(position); notifyDataSetChanged(); } 

}

RecyclerViewFragment

 public class RecyclerViewFragment extends Fragment { private RecyclerView mRecyclerView; private RecyclerView.Adapter mAdapter; private static final int ITEM_COUNT = 2; private List<Object> mContentItems = new ArrayList<>(); private static List<VideoDetails> mContentItems2 = new ArrayList<>(); public static RecyclerViewFragment newInstance() { return new RecyclerViewFragment(); } public static RecyclerViewFragment newInstance(List<VideoDetails> contentItems) { RecyclerViewFragment myFragment = new RecyclerViewFragment(); // mContentItems = contentItems; Bundle args = new Bundle(); args.putSerializable("thienvan", (Serializable) contentItems); myFragment.setArguments(args); return myFragment; } @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { mContentItems2 = (List<VideoDetails>) getArguments().getSerializable("thienvan"); // Log.d("thien.van","Fragment file name = "+mContentItems2.get(0).getTitle()); return inflater.inflate(R.layout.fragment_recyclerview, container, false); } @Override public void onViewCreated(View view, @Nullable Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView); RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity()); mRecyclerView.setLayoutManager(layoutManager); //mRecyclerView.setHasFixedSize(true); mAdapter = new RecyclerViewMaterialAdapter(new RecyclerViewAdapter(getActivity().getBaseContext(),mContentItems2)); mRecyclerView.setAdapter(mAdapter); /*{ for (int i = 0; i < ITEM_COUNT; ++i) mContentItems.add(new Object()); mAdapter.notifyDataSetChanged(); }*/ MaterialViewPagerHelper.registerRecyclerView(getActivity(), mRecyclerView, null); } //http://android--code.blogspot.com/2015/12/android-recyclerview-add-remove-item.html 

}

I could not delete the item inside the adapter class. Can anybody help me?

Answer 1

To get the correct position to delete, you must call holder.getAdapterPosition() and use this value for all delete and notification operations. Android Studio shows a warning for this, so check the warnings first. And why getItemCount you return 2 for getItemCount ?

 public void onClick(View view) { int newPosition = holder.getAdapterPosition(); Log.d("thien.van","on Click onBindViewHolder"); contents2.remove(newPosition); notifyItemRemoved(newPosition); notifyItemRangeChanged(newPosition, contents2.size()); } 

Answer 2

Delete one item

Remove from the list of "Pigs."

 int removeIndex = 2; data.remove(removeIndex); adapter.notifyItemRemoved(removeIndex); 

Delete multiple items

Remove Camel and Sheep from the list.

 int startIndex = 2; // inclusive int endIndex = 4; // exclusive int count = endIndex - startIndex; // 2 items will be removed data.subList(startIndex, endIndex).clear(); adapter.notifyItemRangeRemoved(startIndex, count); 

Delete all items

Clear the entire list.

 data.clear(); adapter.notifyDataSetChanged();