使用 volley json 数据的片段中的 Recyclerview？

Question

请任何人解释片段中的 RecyclerView 使用 volley 获取 json 数据。我已经在下面提到 link 编码 Google recyclerview in fragment

这是我在 android 中的第一个项目，所以我无法理解该编码。请任何人帮助我。

我的 fragmnet 编码：

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View drawer = inflater.inflate(R.layout.fragment_progress, container, false);
    orderLists = new ArrayList<>();

    getProgressData();

    recyclerView = (RecyclerView) drawer.findViewById(R.id.progress);
    adapter = new ProgressOrderListAdapter(orderLists, this);
    adapter.clearAdaptor();
    recyclerView.setAdapter(adapter);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));

    return recyclerView;
}

private void getProgressData(){
    String mobilecustomertoken = SharedPreferencesManager.readPreferenceString("MobileCustomerToken", "D/N");
    JSONObject progressData = new JSONObject();
    try{
        progressData.put("mobilecustomertoken", mobilecustomertoken);
        JsonObjectRequest progressObject = new JsonObjectRequest(1, Common.OrderDetails + "progress", progressData, new Response.Listener<JSONObject>() {
            @Override
            public void onResponse(JSONObject progressResponse) {
                Log.d("Responseprogress", progressResponse.toString());
                try {
                    int status = progressResponse.getInt("status");
                    if(status == 1) {
                        progressOrderProgress(progressResponse);
                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                error.printStackTrace();
                Log.d("Response", "PROGRESS ERROR");
            }
        });
        progressObject.setShouldCache(false);
        ServiceBellApp.getInstance().addToRequestQueue(progressObject);
    }
    catch (JSONException localJSONException){
        localJSONException.printStackTrace();
        return;
    }
}

private void progressOrderProgress(JSONObject progressResponse) throws JSONException {
    JSONArray result = progressResponse.getJSONArray("orderdata");
    OrderList orderListModule = new OrderList();
    for(int i=0; i<result.length(); i++){
        JSONObject orderData = result.getJSONObject(i);
        orderListModule.setPackage_name(orderData.getString("package_name"));
        orderListModule.setOrderdate(orderData.getString("orderdate"));
        orderListModule.setServicedate(orderData.getString("servicedate"));
        orderListModule.setServicetime(orderData.getString("servicetime"));
        orderListModule.setOrderid(orderData.getString("orderid"));
        orderListModule.setOrdstatus(orderData.getString("ordstatus"));
        orderListModule.setOrderamount(orderData.getInt("orderamount"));
    }
    orderLists.add(orderListModule);
}

我的适配器代码：

public class OrderListAdapter extends RecyclerView.Adapter<OrderListAdapter.ViewHolder> {
List<OrderList> List;
private FragmentPending mContext;

public OrderListAdapter(List<OrderList> List, FragmentPending context) {
    this.mContext = context;
    this.List = List;

}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.order_list_view, null);
    ViewHolder holder = new ViewHolder(view);
    // this is where the each item is inflated.

    return holder;
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    OrderList orderListsPos = List.get(position);
    // this is where the data for each item is assigned
    holder.textViewPackageName.setText(orderListsPos.getPackage_name());
    holder.textOrderdate.setText(orderListsPos.getOrderdate());
    holder.textServicedate.setText(orderListsPos.getServicedate());
    holder.textServicetime.setText(orderListsPos.getServicetime());
    holder.textOrderid.setText(orderListsPos.getOrderid());
    holder.textOrderamount.setText("Rs." + orderListsPos.getOrderamount());
    holder.textStatus.setText(orderListsPos.getOrdstatus());

}

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

public void clearAdaptor() {
    List.clear();
}


public class ViewHolder extends RecyclerView.ViewHolder {
    public TextView textViewPackageName;
    public TextView textServicedate;
    public TextView textServicetime;
    public TextView textOrderdate;
    public TextView textOrderid;
    public TextView textOrderamount;
    public TextView textStatus;

    public ViewHolder(View itemView) {
        super(itemView);
        textViewPackageName = (TextView) itemView.findViewById(R.id.productName);
        textOrderdate = (TextView) itemView.findViewById(R.id.orderdate);
        textOrderid = (TextView) itemView.findViewById(R.id.orderno);
        textOrderamount = (TextView) itemView.findViewById(R.id.orderprice);
        textStatus = (TextView) itemView.findViewById(R.id.orderstatus);

    }
}}

Answer 1

查看这个link对于初学者从入门到掌握RecyclerView的概念非常有帮助。

https://github.com/codepath/android_guides/wiki/Using-the-RecyclerView

希望这有助于您理解回收器视图的概念。

Answer 2

首先你需要四样东西

1 ) layout that holds the each recycler view layout item

2 ) A view holder for creating each layout

3 ) A Model Class to holds the data

4 ) Recycler Adaptor which deals with the data for the Each Layout item

首先创建一个布局项

例如，让我们创建一个只有 TextView 的视图

XML

each_item.xml

   <TextView
        android:id="@+id/name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="2dp"
        android:gravity="start|center_vertical"
        android:textColor="@color/white"
        android:textSize="18sp" />

现在让我们创建一个视图持有者我将 post view holder 和 RecyclerAdaptor 的代码

public class Adaptor extends RecyclerView.Adapter<Adaptor.ViewHolder> {
  List<Model> List = Collections.emptyList();
  private Context mContext;
  private LayoutInflater inflater;

  public Adaptor(Context context, List<Model> List) {
    inflater = LayoutInflater.from(context);
    this.mContext = context;
    this.List = List;

 }


@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = inflater.inflate(R.layout.each_item, parent, false);
    final ViewHolder holder = new ViewHolder(view);
    // this is where the each item is inflated.

    return holder;
}

@Override
public void onBindViewHolder(WinnersViewHolder holder, int position) {
    Model mModel = List.get(position); 
    // this is where the data for each item is assigned
    holder.nameView.setText("" + mModel.getName());
  
}

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

public void clearAdaptor() {
    List.clear();
}


public class ViewHolder extends RecyclerView.ViewHolder {
    protected TextView nameView;

    public ViewHolder(View itemView) {
        super(itemView);
        this.nameView = (TextView) itemView.findViewById(R.id.name);
        
    }
 }
}

现模型class

public class Model {

private String name;

public String getName() {
    return name;
}

public void setName(String name) {
    this.name= name;
 }
}

现在后端已经完成，让我们在Fragment上实现它

List<Model> List = new ArrayList<>();
private RecyclerView mRecyclerView;
private Adaptor adaptor;

public Fragment() {
    // constructor of fragment
    // Required empty public constructor
}

在onCreatView()中获取recyclerView的id

 View fragmentView = inflater.inflate(R.layout.fragment_layout, container, false);
 mRecyclerView = (RecyclerView) fragmentView .findViewById(R.id.recycler_view);

然后通过创建对象

将数据传递给Adaptor

    adaptor = new Adaptor(getContext(), List);
    adaptor.clearAdaptor();
    mRecyclerView.setAdapter(adaptor);
    mRecyclerView.setHasFixedSize(true);
    mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity(), LinearLayoutManager.VERTICAL, false));

你现在已经完成了，唯一未决的是如果你正在访问数据表单服务器调用 notifyDataSetChanged() 或 adaptor = new Adaptor(getContext(), getList()); 其中 getList() returns 模型数据并执行不打电话 adaptor.clearAdaptor() .

希望这对您有所帮助..

编辑你可以通过两种方式来影响每个布局项目.. 一种在上面，第二种在 onCreateViewHolder

 View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.each_item, null);

Answer 3

RecycerView + 片段 + Volley

片段代码：

public class DogListFragment extends Fragment{

    private RecyclerView rv;
    private StaggeredGridLayoutManager llm;
    private DogListAdapter adapter;
    private ArrayList<DogModel> dogList;
    private Context context;

    public static DogListFragment getInstance(){
        return new DogListFragment();
    }

    @Override
    public void onCreate(Bundle savedInstanceState){

        super.onCreate(savedInstanceState);
        dogList = new ArrayList<>();
        adapter = new DogListAdapter(context, dogList, this);
        getListFromServer();

    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState){

        View view = inflater.inflate(R.layout.fragment_dog_list, parent, false);
        rv = view.findViewById(R.id.rv);
        llm = new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
        rv.setLayoutManager(llm);
        rv.setAdapter(adapter);
        return view;
    }

    public void getListFromServer(){

        String url = "https://dog.ceo/api/breed/hound/images/random/20";
        RequestQueue requestQueue = Volley.newRequestQueue(context);

        StringRequest request = new StringRequest(Request.Method.GET, url,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    try {
                        JSONObject jsonObject = new JSONObject(response);

                        JSONArray array = jsonObject.getJSONArray("message");

                        for(int i=0;i<array.length();i++){
                            String imageUrl = array.getString(i);
                            dogList.add(new DogModel(imageUrl));
                        }
                        adapter.updateDataSet(dogList);
                    } catch (JSONException e) {
                        e.printStackTrace();
                    }
                }
            }, 
            new Response.ErrorListener() {
               @Override
               public void onErrorResponse(VolleyError error) {
               }
            }
        );

        requestQueue.add(request);
    }

}

完整代码

Woof Repository

它有以下实现

通过接口进行片段通信
重复使用片段 getSupportFragmentManager().findFragmentByTag(TAG)
哪个生命周期方法应该 API 调用以便它被调用一次
如何在Fragment中保存RecylcerView状态（滚动位置+内容）
RecyclerView 中的分页
休息电话（排球）
图像渲染（Glide）
JSON 正在解析

使用 volley json 数据的片段中的 Recyclerview？

Recyclerview in fragmnet using volley json data?

android

fragment

android-adapter

android-fragments

android-recyclerview

RecycerView + 片段 + Volley

完整代码