如何将日期从适配器更新到 recyclerView？

Question

当我发送新数据或更新信息时，如何更改我的回收视图？

我使用了dapter.notifyDataSetChanged(); ，但它不起作用...

我尝试了更多方法，但这一切都无法改变我的回收站视图

在我的代码中

 recyclerView =  view.findViewById(R.id.recyclerCoin);
        recyclerView.setHasFixedSize(true);
        layoutManager = new LinearLayoutManager(getActivity());
        recyclerView.setLayoutManager(layoutManager);
        listCoinDiamondModel = new ArrayList<>();
        requestQueue = Volley.newRequestQueue(getActivity());
        getData();
        adapter = new CoinAdapter(listCoinDiamondModel, getActivity());
        recyclerView.setAdapter(adapter);

private void sendGift(String postUserID) {
        final String postUserIDD = postUserID;
        final String GiftAmount = this.GiftAmount.getText().toString().trim();
        final String flag = "1";
        StringRequest stringRequest = new StringRequest(Request.Method.POST, URL_GIFTCOIN,
                new Response.Listener<String>() {
                    @Override
                    public void onResponse(String response) {
                        try {
                            JSONObject jsonObject = new JSONObject(response);
                            String success = jsonObject.getString("success");
                            if (success.equals("1")){
                                adapter.notifyDataSetChanged();
                            }

                        } catch (JSONException e) {
                            e.printStackTrace();
                            Toast.makeText(getApplicationContext(),e.getMessage(), Toast.LENGTH_SHORT).show();
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        Toast.makeText(getApplicationContext(),"Error" + error.toString(), Toast.LENGTH_SHORT).show();
                    }
                })
        {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> params = new HashMap<>();
                //Log.d("FID", fid);
                params.put("fid", fid);
                params.put("GiftAmount", GiftAmount);
                params.put("flag", flag);
                params.put("postUserID", postUserIDD);
                params.put("uid", getID);
                return params;
            }
        };
        RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext());
        requestQueue.add(stringRequest);
    }


    private JsonArrayRequest getDataFromServer(int requestCount) {
        //Initializing ProgressBar
        final ProgressDialog progressDialog = new ProgressDialog(getActivity());
        progressDialog.setMessage("Load...");
        progressDialog.dismiss();
        final String GROUP_LIST = "https://example.com/aaa.php?flag=1&fid="+ getActivity().getIntent().getStringExtra("fid") +"&page="+requestCount;
        JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(GROUP_LIST,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        parseData(response);
                        progressDialog.dismiss();
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        progressDialog.dismiss();

                        Toast.makeText(getActivity(), "No More gift Available", Toast.LENGTH_SHORT).show();
                    }
                });

        //Returning the request
        return jsonArrayRequest;
    }

    //This method will get data from the web api
    private void getData() {
        requestQueue.add(getDataFromServer(requestCount));
        requestCount++;
    }

    //This method will parse json data
    private void parseData(JSONArray array) {
        for (int i = 0; i < array.length(); i++) {
            //Creating the newFeedModel object

            final CoinDiamondModel coinDiamondModel = new CoinDiamondModel();
            JSONObject json = null;
            try {
                //Getting json
                json = array.getJSONObject(i);

                String TAG_Coin = "Coin";
                String TAG_Diamond = "Diamond";
                String TAG_UserName = "UserName";
                String TAG_UserPhoto = "UserPhoto";
                String TAG_UserID = "UserID";

                //Log.d("NAME111", json.getString(json.getString(TAG_UserName)));
                coinDiamondModel.setCoin(json.getString(TAG_Coin));
                coinDiamondModel.setDiamond(json.getString(TAG_Diamond));
                coinDiamondModel.setGiftFromUserName(json.getString(TAG_UserName));
                coinDiamondModel.setGiftFromUserPhoto(json.getString(TAG_UserPhoto));
                coinDiamondModel.setGiftFromUserID(json.getString(TAG_UserID));

            } catch (JSONException e) {
                e.printStackTrace();
            }
            //Adding the newFeedModel object to the list
            listCoinDiamondModel.add(coinDiamondModel);
            //adapter.addTheCoinData(coinDiamondModel);
        }

        //Notifying the adapter that data has been added or changed
        adapter.notifyDataSetChanged();
    }

谁知道发生了什么以及如何解决这个问题？

你能告诉我我该怎么做吗？

适配器所有代码

public class CoinAdapter extends RecyclerView.Adapter<CoinAdapter.ViewHolder> {
    private ImageLoader imageLoader;
    private List<CoinDiamondModel> newcoinDiamondLists;
    private RequestManager glide;
    private Context context;
    SessionManager sessionManager;
    private String getID,memail;

    public CoinAdapter(List<CoinDiamondModel> newcoinDiamondLists, Context context) {
        this.newcoinDiamondLists = newcoinDiamondLists;
        this.glide = Glide.with(context);
        this.context = context;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.coinlist, parent, false);
        ViewHolder viewHolder = new ViewHolder(v);

        sessionManager = new SessionManager(getApplicationContext());
        sessionManager.checkLogin();
        HashMap<String, String> user = sessionManager.getUserDetail();
        getID = user.get(sessionManager.USERID);
        memail = user.get(sessionManager.EMAIL);

        //String gid = getIntent.getStringExtra("xxx");


        return viewHolder;
    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        CoinDiamondModel newCoinDiamondModel = newcoinDiamondLists.get(position);
        imageLoader = CustomVolleyRequest.getInstance(context).getImageLoader();

        holder.userName.setText(newCoinDiamondModel.getGiftFromUserName());
        holder.userID.setText(newCoinDiamondModel.getGiftFromUserID());
        holder.coinCount.setText(" x "+newCoinDiamondModel.getCoin());
        glide.load(newCoinDiamondModel.getGiftFromUserPhoto()).into(holder.userPhoto);
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        CircleImageView userPhoto;
        TextView userName,userID,coinCount;
        ImageView coinImg;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            userPhoto = (CircleImageView) itemView.findViewById(R.id.userPhoto);
            userName = (TextView) itemView.findViewById(R.id.userName);
            coinCount = (TextView) itemView.findViewById(R.id.coinCount);
            userID = (TextView) itemView.findViewById(R.id.userID);
            coinImg = (ImageView) itemView.findViewById(R.id.coinImg);
        }
    }

    public void addTheCoinData(CoinDiamondModel coinDiamondModel){
        if(coinDiamondModel!=null){
            newcoinDiamondLists.add(coinDiamondModel);
            notifyDataSetChanged();
        }else {
            throw new IllegalArgumentException("無資料!");
        }

    }
}

Answer 1

您可以在服务器响应后再次将适配器设置为回收站视图

   public void onResponse(JSONArray response) {
                    parseData(response);
                    progressDialog.dismiss();
                    adapter = new CoinAdapter(listCoinDiamondModel, getActivity());
                    recyclerView.setAdapter(adapter);
                }

解决方案 2：在您的适配器中编写一个函数来更新您的列表并在活动中调用函数

将此功能添加到适配器

    public void updateList(List<CoinDiamondModel> list){
    newcoinDiamondLists = list;
    notifyDataSetChanged();
     }

并在您需要更新 recyclerview 时调用函数updateList

Answer 2

RecyclerView 初始化和notifyDataSetChanged()使用得当。 由于您的问题对 RecyclerView 的 Adapter 实现不够清楚，我可以给您几个建议以供检查。

1. 在RecyclerView.Adapter检查getItemCount()方法是否正确覆盖并返回列表长度（不是 0），如下所示：

 @Override public int getItemCount() { return listdata.length; }

2. 在RecyclerView.Adapter检查onCreateViewHolder方法是否被正确的 xml 布局正确覆盖，如下所示：

 @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext()); View listItem= layoutInflater.inflate(R.layout.coin_xml_layout, parent, false); ViewHolder viewHolder = new ViewHolder(listItem); return viewHolder; }

3. 在RecyclerView.Adapter检查RecyclerView.ViewHolder类是否正确扩展并将 xml 中的 UI 元素与适配器链接，如下所示：

 public static class ViewHolder extends RecyclerView.ViewHolder { public TextView coinTextView; public ViewHolder(View itemView) { super(itemView); this.coinTextView = (TextView) itemView.findViewById(R.id.coinTextView); } }

4. 在RecyclerView.Adapter检查onBindViewHolder方法是否被正确覆盖并正确更新列表组件 UI，如下所示：

 @Override public void onBindViewHolder(ViewHolder holder, int position) { final MyListData myListData = listdata[position]; holder.cointTextView.setText(listdata[position].getCoin()); }

5. 使用断点进行调试并检查listCoinDiamondModel.add(coinDiamondModel)是否正在调用并且coinDiamondModel对象不为空。
6. RecyclerView 被正确地放置在活动 xml 中，就像 RecyclerView 是可见的一样，有一个合适的大小来显示列表元素。 举个例子：

 android:layout_width="match_parent" android:layout_height="match_parent" android:scrollbars="vertical"

Answer 3

你可以像这样手动更新你的适配器列表:(在你的适配器中写这个函数）

public void updateCoinAdapterList(ArrayList<listCoinDiamondModel> recyclerItemsList) {
        this.recyclerItemsList = recyclerItemsList;
        this.notifyDataSetChanged();
    }

您必须设置您的适配器全局变量并在 OnCreate 或 OnResume 中对其进行初始化，然后调用

adapter.updateCoinAdapterList(listCoinDiamondModel);

当你的名单改变时