如何在Android中使用Retrofit在recyclerView中设置数据

Question

I want to show some data into recyclerview and for this I am using the code displayed below.

When I run the application, it's not showing me any data into recyclerview and ListData.size() is 0 , but in PostMan

I write below code for set into recyclerView :

InterfaceApi api = ApiClient.getClient().create(InterfaceApi.class);
Call<CommentResponse> call = api.getComments(sendData);

call.enqueue(new Callback<CommentResponse>() {
    @Override
    public void onResponse(Call<CommentResponse> call, Response<CommentResponse> response) {
        if (response.body().getData() != null) {
            commentModel.clear();
            commentModel.addAll(response.body().getData());
            commentsListAdapter.notifyDataSetChanged();
            content_newsCommentsRecyclerView.setAdapter(commentsListAdapter);
        }
    }

    @Override
    public void onFailure(Call<CommentResponse> call, Throwable t) {

    }
});

My Adapter codes:

public class CommentsListAdapter extends RecyclerView.Adapter<CommentsListAdapter.ViewHolder> {

    private Context context;
    private List<CommentData> model;

    public CommentsListAdapter(Context context, List<CommentData> model) {
        this.context = context;
        this.model = model;
    }

    @Override
    public CommentsListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_comment, parent, false);

        return new CommentsListAdapter.ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final CommentsListAdapter.ViewHolder holder, final int position) {

        holder.row_commentNameTxt.setText(Html.fromHtml(model.get(position).getOwner().getName()));
        holder.row_commentCommentTxt.setText(Html.fromHtml(model.get(position).getText()));
        Glide.with(context)
                .load(model.get(position).getOwner().getImageUrl())
                .placeholder(R.drawable.default_image)
                .diskCacheStrategy(DiskCacheStrategy.ALL)
                .listener(new RequestListener<String, GlideDrawable>() {
                    @Override
                    public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {
                        return false;
                    }

                    @Override
                    public boolean onResourceReady(GlideDrawable resource, String model,
                                                   Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
                        return false;
                    }
                })
                .into(holder.row_commentProfileImage);
        holder.row_commentLikeTxt.setText(model.get(position).getLikeCount() + "");
        holder.row_commentReplayTxt.setText(model.get(position).getRepliesCount() + "");
        holder.row_commentDateTxt.setText(model.get(position).getSubmitDate() + " " + model.get(position).getSubmitTime());
    }

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

    public void addNewItem(List<CommentData> newContent) {
        int start = this.model.size();
        int end = newContent.size();
        model.addAll(newContent);
        notifyDataSetChanged();
    }

    public void clear() {
        model.clear();
        notifyDataSetChanged();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        private CircleImageView row_commentProfileImage;
        private TextView row_commentNameTxt, row_commentCommentTxt, row_commentLikeTxt, row_commentReplayTxt, row_commentDateTxt;

        public ViewHolder(View itemView) {
            super(itemView);

            row_commentProfileImage = (CircleImageView) itemView.findViewById(R.id.row_commentProfileImage);
            row_commentNameTxt = (TextView) itemView.findViewById(R.id.row_commentNameTxt);
            row_commentCommentTxt = (TextView) itemView.findViewById(R.id.row_commentCommentTxt);
            row_commentLikeTxt = (TextView) itemView.findViewById(R.id.row_commentLikeTxt);
            row_commentReplayTxt = (TextView) itemView.findViewById(R.id.row_commentReplayTxt);
            row_commentDateTxt = (TextView) itemView.findViewById(R.id.row_commentDateTxt);

        }
    }
}

How can I display the data into recyclerView ?

Answer 1

Create a method inside your Adapter class

       //This will add all the items in the adapter's list
       public  void addAllItems(List<CommentData> items) {
                model.addAll(items);
                notifyDataSetChanged();
            }

//In Adapter's Constructor do the following changes
 public CommentsListAdapter(Context context, List<CommentData> model) {
        this.context = context;
        this.model = new ArrayList<>;
    }

and when you are fetching your response you can call this by

//Inside your onCreate add the below code 

        mAdapter = new CommentsListAdapter (this);
        content_newsCommentsRecyclerView.setLayoutManager(new LinearLayoutManager(this));
        content_newsCommentsRecyclerView.setAdapter(mAdapter);

//Call this inside your success of onResponse
commentsListAdapter.addAllItems(commentModel);

This will update the content of recyclerView and notify the changes made, do try this and let me know if you have any issue.

Answer 2

Before the API call initialize the Adapter

mLayoutManager = new LinearLayoutManager(getActivity());
mLayoutManager.setOrientation(LinearLayoutManager.VERTICAL);
mRVCommentList.setLayoutManager(mLayoutManager);
CommentsListAdapter commentsListAdapter= new CommentsListAdapter(this)
mRVCommentList.setAdapter(commentsListAdapter) 

Then call the API

public void onResponse(Call<CommentResponse> call, Response<CommentResponse> response) {
        if (response.body().getData() != null) {
            List<CommentData> list= response.body().getData().getCommentData();
            commentsListAdapter.setData(list);
         }
    }

Small changes in Adapter Class

private List<CommentData> commentData;

 public CommentsListAdapter(Context context) {
        this.context = context;
        this.commentData = new ArrayList<>();
    }

 public void setData(List<CommentData> commentData) {
        this.commentData= commentData;
        notifyDataSetChanged();
    }