Android JSON 对象解析存储在数组列表中，每次单击按钮时都会更改

Question

我在将JSON数据解析到我的安卓应用程序时遇到问题。我需要解析如下所示的 JSON 对象。对于我的应用程序，我想拉取此 json 数据存储在数组中。然后使用文本视图和按钮显示每个问题以及可能的答案。然后，我想显示数组中的下一个问题以及可能的答案。

JSON 对象

 {
    "52f66c6eb82944cc1c00002a": {
        "_id": {
            "$id": "52f66c6eb82944cc1c00002a"
        },
        "Question": "Capital city of England",
        "Answer 1": "Paris",
        "Answer 2": "Liverpool",
        "Correct Answer": "London"
    },
    "52f66c8ab82944780d000029": {
        "_id": {
            "$id": "52f66c8ab82944780d000029"
        },
        "Question": "Capital city of Ireland",
        "Answer 1": "Cork",
        "Answer 2": "Liverpool",
        "Correct Answer": "Dublin"
    }
}

安卓代码

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.os.StrictMode;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
    protected TextView TitleTextView;
    protected Button PossibleAnswer1;
    protected Button PossibleAnswer2;
    protected Button CorrectAnswer;
    protected String URL ="http://127.0.0.1/mongo-form-create-quiz/processform.php";
    protected HttpClient HTTPClient;
    protected HttpPost HTTPPost;
    protected HttpResponse ResponseFromWeb;
    protected String JSONString;
    protected JSONObject JSONObject;
    protected String JSONQuestion;
    protected String JSONPossibleAnswer1;
    protected String JSONPossibleAnswer2;
    protected String JSONCorrectAnswer;
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppostresponse = new HttpPost("http://127.0.0.1/mongo-form-create-quiz/recordinput.php");
    Intent openLastActivity = new Intent("com.example.quizqizzdemo.LASTACTIVITY");

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        StrictMode.ThreadPolicy policy = new StrictMode.
        ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy); 
        setContentView(R.layout.activity_main);
        HTTPClient = new DefaultHttpClient();
        HTTPPost = new HttpPost(URL);
        TitleTextView = (TextView) findViewById(R.id.Question_Title);

        PossibleAnswer1 = (Button) findViewById(R.id.PossibleAnswer1);
        PossibleAnswer2 = (Button) findViewById(R.id.PossibleAnswer2);
        CorrectAnswer = (Button) findViewById(R.id.CorrectAnswer);
        try{
            ResponseFromWeb = HTTPClient.execute(HTTPPost);
            JSONString = FormatJSONInput(
                    ResponseFromWeb.getEntity().getContent()).toString();
            JSONObject = new JSONObject(JSONString);
            JSONQuestion = JSONObject.getString("Question");
            JSONPossibleAnswer1 = JSONObject.getString("Answer 1");
            JSONPossibleAnswer2 = JSONObject.getString("Answer 2");
            JSONCorrectAnswer = JSONObject.getString("Correct Answer");
            TitleTextView.setText(JSONQuestion);
            PossibleAnswer1.setText(JSONPossibleAnswer1);
            PossibleAnswer2.setText(JSONPossibleAnswer2);
            CorrectAnswer.setText(JSONCorrectAnswer);
        }
    catch (JSONException e) {
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

        PossibleAnswer1.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View arg0) {
                  /*
                 Toast.makeText(getApplicationContext(), 
                               "Incorrect!!", Toast.LENGTH_LONG).show();
                 PossibleAnswer1.setBackgroundColor(Color.RED);
                 */
                    try {
                        // Add your data
                        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
                        nameValuePairs.add(new BasicNameValuePair("UserAnswer", JSONPossibleAnswer1));
                        nameValuePairs.add(new BasicNameValuePair("CorrectAnswer", JSONCorrectAnswer));
                        httppostresponse.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                        // Execute HTTP Post Request
                        HttpResponse response = httpclient.execute(httppostresponse);

                        startActivity(openLastActivity);
                    } catch (ClientProtocolException e) {
                        // TODO Auto-generated catch block
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                    }
              }
        });
        PossibleAnswer2.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View arg0) {
                  /*
                 Toast.makeText(getApplicationContext(), 
                             "Incorrect!!", Toast.LENGTH_LONG).show();
                 PossibleAnswer1.setBackgroundColor(Color.RED);
                 */
                    try {
                        // Add your data
                        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
                        nameValuePairs.add(new BasicNameValuePair("UserAnswer", JSONPossibleAnswer2));
                        nameValuePairs.add(new BasicNameValuePair("CorrectAnswer", JSONCorrectAnswer));
                        httppostresponse.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                        // Execute HTTP Post Request
                        HttpResponse response = httpclient.execute(httppostresponse);
                        startActivity(openLastActivity);
                    } catch (ClientProtocolException e) {
                        // TODO Auto-generated catch block
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                    }
              }
        });
        CorrectAnswer.setOnClickListener(new OnClickListener() {
              @Override
              public void onClick(View arg0) {
                  /*
                 Toast.makeText(getApplicationContext(), 
                             "Correct!!", Toast.LENGTH_LONG).show();
                 CorrectAnswer.setBackgroundColor(Color.GREEN);
                 */
                try {
                    // Add your data
                    List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
                    nameValuePairs.add(new BasicNameValuePair("UserAnswer", JSONCorrectAnswer));
                    nameValuePairs.add(new BasicNameValuePair("CorrectAnswer", JSONCorrectAnswer));
                    httppostresponse.setEntity(new UrlEncodedFormEntity(nameValuePairs));
                    // Execute HTTP Post Request
                    HttpResponse response = httpclient.execute(httppostresponse);
                    startActivity(openLastActivity);
                } catch (ClientProtocolException e) {
                    // TODO Auto-generated catch block
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                }
              }
        });
    }
    private StringBuilder FormatJSONInput(InputStream is) {
        String ReadLine = "";
        StringBuilder CorrectDBData = new StringBuilder();
        BufferedReader rd = new BufferedReader(new InputStreamReader(is));
        try {
            while ((ReadLine = rd.readLine()) != null) {
                CorrectDBData.append(ReadLine);
            }
        }
        catch (IOException e) {
            e.printStackTrace();
        }
        return CorrectDBData;
    }
}

我可以使用字符串数组来执行此操作，但对于我的应用程序，我需要显示来自 mongohq 数据库的数据。

我是一名学生，是Android，json和mongodb的新手。

Answer 1

如果您每次按下按钮时都会从服务器中提取新问题。我建议您将这些代码放入新方法中，然后在onClick()方法中完成工作时调用方法

但是，如果您只是一次收到所有问题，我建议您将其转换为JSONObject就像您所做的那样

，然后这样做

ArrayList<JSONObject> list = new ArrayList<JSONObject>();
JSONArray names = json.names();
for(int i =0; i<json.length();i++){
   JSONObject innerJson = json.getJSONObject(names.optString(i));
   /* put stuffs in object*/
   /* add object to list */
   list.add("parse object");
}

当你

按下下一步按钮时，你得到一个列表后，你只会从列表中获取你的对象。