notifyItemInsertedRange（）无法处理recyclerview适配器

Question

I used recyclerview on my project. I have a problem updating the data. I want to use notifyItemRangeInserted() or notifyItemInserted() method but none of them are working(the arraylist are updated, but the new item is not showing in the recyclerview). It's really confusing because notifyDataSetChanged() is works.

I have tried both notifyItemInserted(index) and notifyItemRangeInserted(startIndex, insertedCount) but none of them works. I also have googled this problem but I didn't find a similar problem.

RequestQueue queue = Volley.newRequestQueue(this);
        StringRequest postRequest = new StringRequest(Request.Method.POST, UrlHouse.MOMENT_EXTENTION,
                response -> {
                    // response
                    Log.e("moment_extention", response);
                    try {
                        JSONArray momentArray = new JSONArray(response);
                        CustomJsonParser jsonParser = new CustomJsonParser(this);
                        for(int i = 0; i < momentArray.length(); i++){
                            JSONObject c = momentArray.getJSONObject(i);
                            momentArrayList.add(jsonParser.parseMomentData(c));
                        }
                        if (momentArray.length() > 0){
                            runOnUiThread(() -> {
                                Log.e("item_count", String.valueOf(mAdapter.getItemCount()));
                                //mAdapter.notifyDataSetChanged();
                                //mAdapter.notifyItemInserted(10);
                                mAdapter.notifyItemRangeInserted(momentArrayList.size() - momentArray.length(), momentArray.length());
                            });
                        }
                        if (momentArray.length()  < 10){
                            stopLoading = true;
                            extentionLoading.setVisibility(View.GONE);
                        }else{
                            extentionLoading.setVisibility(View.VISIBLE);
                        }
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                },
                error -> {
                    // error
                }
        ) {
            @Override
            protected Map<String, String> getParams()
            {
                Map<String, String>  params = new HashMap<String, String>();
                params.put("key_owner", userData.getUserId());
                params.put("session_key", userData.getLoginKey());
                params.put("user_id", userData.getUserId());
                params.put("excluded_post", getExcludedPost());
                return params;
            }
        };
        postRequest.setRetryPolicy(new DefaultRetryPolicy(24 * 60 * 60 * 1000, 0, 1f) );
        queue.add(postRequest);

I want the recyclerview item updated the new data. in my case, after updating the adapter it should be 20 item displayed on the screen(10 the original item and 10 is the new item), but instead of displaying 20 item its only displaying 10 item(only the original 10 item)

Answer 1

You are using momentArray.length() as endPoint of range and that's why it is not working.

So just replace below line in runOnUiThread(),

mAdapter.notifyItemRangeInserted(momentArrayList.size() - momentArray.length(), momentArray.length());

To,

mAdapter.notifyItemRangeInserted(momentArrayList.size() - momentArray.length() + 1, momentArray.length());