Question

我有一个我用Volley创建的JSON List RecyclerView。我的recyclerview有大约1000个项目，但我只想显示50个项目，但仍然从JSON加载所有项目，因此当用户使用搜索工具时，它将搜索整个JSON数据。

我可以让我的recyclerview显示我想要的数量，50，但是当我使用搜索工具时我只能搜索50.ive寻找答案但似乎无法找到任何关于如何加载所有项目但只显示50.有人可以帮忙吗？

MainActivity 的

public class HomeFragment extends Fragment {

public static final String URL_DATA = "https://api.coinmarketcap.com/v1/ticker/";
private RecyclerView.Adapter adapter;
private List<ListItem> listItems;
private RecyclerView recyclerView;
private EditText SearchText;


@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_home, container, false);

    listItems = new ArrayList<>();
    recyclerView = (RecyclerView) v.findViewById(R.id.recyclerView);
    SearchText = (EditText) v.findViewById(R.id.search_text);

    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
    loadRecyclerViewData();

    SearchText.addTextChangedListener(new TextWatcher() {
        @Override
        public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

        }

        @Override
        public void afterTextChanged(Editable editable) {
            filter(editable.toString());
        }
    });

    return v;
}


private void filter(String text){
    List<ListItem> filteredList = new ArrayList<>();

    for(ListItem item :listItems ){
        if (item.getHead().toLowerCase().contains(text.toLowerCase()) && item.getDesc().toLowerCase().contains(text.toLowerCase())){
            filteredList.add(item);
        }
    }
    adapter = new MyAdapter(filteredList, getContext());
    recyclerView.setAdapter(adapter);
}
private void loadRecyclerViewData() {
    final ProgressDialog progressDialog = new ProgressDialog(getContext());
    progressDialog.setMessage("Loading Data...");
    progressDialog.show();

    StringRequest stringRequest = new StringRequest(Request.Method.GET,
            URL_DATA,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    progressDialog.dismiss();
                    try {
                        JSONArray array = new JSONArray(response);
                        for(int i=0; i < array.length(); i++){
                            JSONObject o = array.getJSONObject(i);
                            ListItem item = new ListItem(
                                    o.getString("name"),

                            );

                            listItems.add(item);
                        }
                        adapter = new MyAdapter(listItems, getContext());
                        recyclerView.setAdapter(adapter);

                    } catch (JSONException e) {
                        e.printStackTrace();
                    }

                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    progressDialog.dismiss();
                    Toast.makeText(getContext(),error.getMessage(), Toast.LENGTH_LONG).show();

                }
            });

    RequestQueue requestQueue = Volley.newRequestQueue(getContext());
    requestQueue.add(stringRequest);
}
}

MyAdapter 的

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<ListItem> listItems;
private Context context;

public MyAdapter(List<ListItem> listItems, Context context) {
    this.listItems = listItems;
    this.context = context;
}

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

    return new ViewHolder(v);

}

@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {
    final ListItem listItem = listItems.get(position);

    holder.textViewHead.setText(listItem.getHead());
    holder.textViewDesc.setText(listItem.getDesc());

public void filterList(ArrayList<ListItem> filteredList){
    this.listItems = filteredList;
    notifyDataSetChanged();
}


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

public class ViewHolder extends RecyclerView.ViewHolder {

    public TextView textViewHead;
    public TextView textViewDesc;

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

        textViewHead = (TextView) itemView.findViewById(R.id.textViewHead);
        textViewDesc = (TextView) itemView.findViewById(R.id.textViewDesc);
    }
}
}

Answer 1

显示的项目数由RecyclerView.Adapter.getItemCount()

的返回值决定

加载整个RecyclerView但仅显示50个项目，除非使用搜索栏

1 个答案: