Question

我正在尝试使用适配器将JSON数据传递给listview。现在我在logcat中遇到错误：

 package ir.homa;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import java.util.ArrayList;

/**
 * Created by SMQ on 9/17/2016.
 */
public class RoomTypeAdapter extends ArrayAdapter<RoomType> {
    public RoomTypeAdapter(Context context, ArrayList<RoomType> roomType) {
        super(context,0, roomType);
    }
    @Override
    public View getView(int position , View ConvertView, ViewGroup parent ){
        RoomType roomType = getItem(position);
        if (ConvertView == null) {

            ConvertView = LayoutInflater.from(getContext()).inflate(R.layout.item_type, parent, false);
        }
        TextView typeItem = (TextView) ConvertView.findViewById(R.id.itemRoomType);
        typeItem.setText(roomType.RoomType);
        return ConvertView;
    }



}

这是我的适配器：

package ir.homa;

import org.json.JSONException;
import org.json.JSONObject;

/**
 * Created by SMQ on 9/17/2016.
 */
public class RoomType {
    String RoomType;
    String id;
    public void setRoomType(JSONObject object) {
        try {
            this.RoomType = object.getString("description");
            this.id = object.getString("id");
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}

这是我的类，其中包含变量：

package ir.homa;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.VolleyLog;
import com.android.volley.toolbox.JsonObjectRequest;
import com.google.android.gms.appindexing.AppIndex;
import com.google.android.gms.common.api.GoogleApiClient;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

/**
 * Created by SMQ on 9/4/2016.
 */
public class HotelDetail extends Activity {


    // json array response url
    private String urlJsonArry = "http://homa.qadamgahi.ir/bandar_result.json";
    private static String TAG = HotelDetail.class.getSimpleName();


    ArrayList<RoomType> typeList;
    RoomTypeAdapter adapter;
    ListView listView;
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        typeList = new ArrayList<>();
        adapter = new RoomTypeAdapter(this, typeList);
        listView = (ListView) findViewById(R.id.listv);
        listView.setAdapter(adapter);



        makeJsonObjectRequest();
        // ATTENTION: This was auto-generated to implement the App Indexing API.
        // See https://g.co/AppIndexing/AndroidStudio for more information.
        /*
      ATTENTION: This was auto-generated to implement the App Indexing API.
      See https://g.co/AppIndexing/AndroidStudio for more information.
     */
        GoogleApiClient client = new GoogleApiClient.Builder(this).addApi(AppIndex.API).build();
    }

    /**
     * Method to make json object request where json response starts wtih {
     * */
    private void makeJsonObjectRequest() {



        JsonObjectRequest jsonObjReq = new JsonObjectRequest(Request.Method.GET,
                urlJsonArry, null, new Response.Listener<JSONObject>() {

            @Override
            public void onResponse(JSONObject response) {
                Log.d(TAG, response.toString());

                // Parsing json object response
                // response will be a json object

                RoomType o = new RoomType();

                try {

                    for (int i = 0 ; i < typeList.size() ; i++)
                    {


                        RoomType add = new RoomType();
                        add.id = response.getString("id");
                        add.RoomType = response.getString("description");
                        typeList.add(add);
                    }

                    adapter.notifyDataSetChanged();


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


            }
        }, new Response.ErrorListener() {

            @Override
            public void onErrorResponse(VolleyError error) {
                VolleyLog.d(TAG, "Error: " + error.getMessage());
                Toast.makeText(getApplicationContext(),
                        error.getMessage(), Toast.LENGTH_SHORT).show();
                // hide the progress dialog

            }
        });

        // Adding request to request queue
        AppController.getInstance().addToRequestQueue(jsonObjReq);
    }

}

这是我的MainActivity：

{{1}}

请告诉我如何使用listview填充json数据，这是什么问题？！

Answer 1

您忘了拨打- (void)addBlurView { CGRect viewBounds = [[UIScreen mainScreen]applicationFrame]; self.myModelView = [[MyModalView alloc] initWithFrame:CGRectMake(viewBounds.origin.x, -16, viewBounds.size.width, viewBounds.size.height+36)]; if(![self toolbar]) { _toolbar = [[UIToolbar alloc] initWithFrame:[self.myModelView bounds]]; [_toolbar setBarStyle:UIBarStyleBlack]; _toolbar.alpha = 0.97; [self.myModelView.layer insertSublayer:_toolbar.layer atIndex:0]; } [self.view addSubview:self.myModelView]; }方法。

setContentView()

尝试在空对象引用致命错误上调用虚方法'void android.widget.ListView.setAdapter（android.widget.ListAdapter）'

1 个答案: