Question

我想用JSON数组加载我的recyclerview。我为此使用排球。

到目前为止，我正在使用StringRequest。

我要发布ID，作为回应，我将获得JSON数组。

我收到响应，但是我的ArrayList显示错误

statuslist ='this' is not available

下面是我的代码。

private ArrayList<Main_lead_data> statusList = new ArrayList<>();
private RecyclerView mainleadRecycler;
private Main_lead_Adpater mainleadRecycler_Adpter;

    mainleadRecycler = findViewById(R.id.idRecyclerViewHorizontalList);
    mainleadRecycler.addItemDecoration(new DividerItemDecoration(MainActivity.this, LinearLayoutManager.HORIZONTAL));
    mainleadRecycler_Adpter = new Main_lead_Adpater(this,statusList);
    LinearLayoutManager horizontalLayoutManager = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
    mainleadRecycler.setLayoutManager(horizontalLayoutManager);
    mainleadRecycler.setAdapter(mainleadRecycler_Adpter);

  public void getLeadStatus(){

    final ProgressDialog progressBar = new ProgressDialog(MainActivity.this);
    progressBar.setMessage("Loading..");
    progressBar.show();
    RequestQueue requestQueue = Volley.newRequestQueue(MainActivity.this);
    StringRequest stringRequest = new StringRequest(Request.Method.POST,leadstatus_url,
            new com.android.volley.Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    if(!response.isEmpty()){
                        try {
                            JSONArray jsonarray=new JSONArray(response);
                          statusList =new ArrayList<Main_lead_data>();

                            for(int i=0;i<jsonarray.length();i++)
                            {
                                JSONObject jsonobject = jsonarray.getJSONObject(i);

                                Main_lead_data data=new Main_lead_data();

                                data.setStatusName((jsonobject.optString("name")));
                                data.setStatusCount(jsonobject.optString("data"));
                                data.setStaus_id(jsonobject.optString("sid"));

                                statusList.add(data);
                            }

                            progressBar.dismiss();
                        } catch (JSONException e) {
                            progressBar.dismiss();
                            Toast.makeText(MainActivity.this,"Server Not Responding..Please Try Again",Toast.LENGTH_SHORT).show();
                            Log.e("catchException",e.toString());
                            e.printStackTrace();
                        }
                    }
                    else {
                        progressBar.dismiss();
                        Toast.makeText(MainActivity.this,"Server Not Responding",Toast.LENGTH_SHORT).show();
                        Log.e("error","Empty Response");
                    }
                }
            },
            new com.android.volley.Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Log.e("error",error.toString());
                    progressBar.dismiss();
                    Toast.makeText(MainActivity.this,"Server Not Responding",Toast.LENGTH_SHORT).show();
                }
            }) {
        @Override
        protected Map<String, String> getParams() {
            Map<String, String> params = new HashMap<String, String>();
            params.put("company_id",companyId );

            return params;
        }
    };

    requestQueue.add(stringRequest);
}

我还想知道如何在JsonArrayRequest方法中传递post参数并获得响应。

以下是适配器类：

public class Main_lead_Adpater extends RecyclerView.Adapter<Main_lead_Adpater.ViewHolder> {
    private Context context;
    private ArrayList<Main_lead_data> lead_data ;
    LinearLayout view_linear;

    public Main_lead_Adpater(Context context,ArrayList<Main_lead_data> lead_data) {
        this.context = context;
        this.lead_data=lead_data;
    }

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

    @Override
    public void onBindViewHolder(final ViewHolder holder, int position) {
        Main_lead_data lead_status = lead_data.get(position);

        holder.textCount.setText(lead_status.getStatusCount());
        holder.textName.setText(String.valueOf(lead_status.getStatusName()));
        holder.textId.setText(String.valueOf(lead_status.getStaus_id()));

        view_linear.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

            }
        });
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        public TextView textCount, textName, textId;

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

            textCount = itemView.findViewById(R.id.total_count);
            textName = itemView.findViewById(R.id.status_name);
            textId = itemView.findViewById(R.id.sid_tv);
            view_linear=(LinearLayout)itemView.findViewById(R.id.view_linear);

        }
    }
}

以下是JSON响应：

[
{
    "name": "New Enquiry",
    "data": "23",
    "sid": "1"
},
{
    "name": "Interested",
    "data": "4",
    "sid": "2"
},
{
    "name": "Not Interested",
    "data": "5",
    "sid": "3"
},
{
    "name": "Proposal Sent",
    "data": "5",
    "sid": "4"
},
{
    "name": "Ongoing",
    "data": "8",
    "sid": "6"
},
{
    "name": "Converted Client",
    "data": "6",
    "sid": "7"
},
{
    "name": "Lost",
    "data": "27",
    "sid": "8"
}]

谢谢。

Answer 1

尝试在获取arraylist之后使用适配器的invoke构造函数，然后设置适配器。这将起作用

Answer 2

您需要用一个空列表更新您已经拥有的适配器列表。从服务器获得响应后，将列表添加到适配器。

将此方法添加到适配器

 public void addItems(ArrayList<Main_lead_data> dataList){
        lead_data.addAll(dataList); 
        notifyDataSetChanged();
    }

此方法会将所有数据添加到列表中，并将数据填充到RecyclerView中。

像这样更改您的onResponse代码：

if(!response.isEmpty()){
      try {
           JSONArray jsonarray=new JSONArray(response);
         // No need to reinitialize statusList here. You already initialize this 
         //  statusList = new ArrayList<Main_lead_data>();

           for(int i=0;i<jsonarray.length();i++)
           {
              JSONObject jsonobject = jsonarray.getJSONObject(i);

              Main_lead_data data = new Main_lead_data();

              data.setStatusName((jsonobject.optString("name")));
              data.setStatusCount(jsonobject.optString("data"));
              data.setStaus_id(jsonobject.optString("sid"));

              statusList.add(data);
           }
             mainleadRecycler_Adpter.addItems(statusList);
             progressBar.dismiss();
            } catch (JSONException e) {
                 progressBar.dismiss();
                 Toast.makeText(MainActivity.this,"Server Not Responding..Please Try Again",Toast.LENGTH_SHORT).show();
                 Log.e("catchException",e.toString());
                 e.printStackTrace();
              }
            }
         else {
               progressBar.dismiss();
               Toast.makeText(MainActivity.this,"Server Not Responding",Toast.LENGTH_SHORT).show();
               Log.e("error","Empty Response");
              }
          }

Answer 3

删除statusList =new ArrayList<Main_lead_data>();块中的StringRequest行。
在mainleadRecycler_Adpter.notifyDataSetChanged()块的progressBar.dismiss();之前添加StringRequest行。

Answer 4

您可以使用jsonschema2pojo 从JSON或JSON-Schema生成普通的旧Java对象。 http://www.jsonschema2pojo.org/

实现'com.google.code.gson：gson：2.6.2' 批注@SerializedName的库

Gson gson =新的Gson（）;

Mainleaddata mainleaddata = gson.fromJson（response.toString（），Mainleaddata.class）;

Answer 5

我不知道出了什么问题，我刚刚创建了一个新项目，只是为了测试它并进行一些小的更改。调试状态列表时出现相同的错误，但我得到了输出。

下面是MAinactivity的代码：

IQueryable<Customer> myCustomers = ...
IEnumerator<Customer> customerEnumerator = myCustomers.GetEnumerator();

while (await customerEnumerator.MoveNextAsync())
{
     Customer customer = customerEnumerator.Current;
     Process(customer);
}

带有后置参数的Volley JsonArrayRequest的Recyclerview android

5 个答案: