ListView 显示相同的数据答案

【问题标题】：ListView displaying same dataListView 显示相同的数据
【发布时间】：2015-12-28 00:52:33
【问题描述】：

我有一个大型 JSON 数组。我正在从 JSON 数组读取数据并将其存储在列表视图中，但列表视图重复相同的数据。

即来自 JSON 的最后一个数据，而不是显示所有数据。

这是我的代码。

public class HistoryActivity extends AppCompatActivity {
private Toolbar toolbar;
String strServerResponse = null;
ProgressDialog nDialog;
Pojo pojo;
ArrayList<Pojo> history;
HistoryAdapter myAdapter;
ListView list;
public String date, inTime, outTime, inLat, inLong;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_history);
    toolbar = (Toolbar) findViewById(R.id.app_bar);
    toolbar.setTitle("History");
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    list = (ListView) findViewById(R.id.historyList);
    history = new ArrayList<Pojo>();
    new NetCheck().execute();

}

private class NetCheck extends AsyncTask<Void, Void, Void> {


    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);

        nDialog.dismiss();
        // TODO Auto-generated method stub
        myAdapter = new HistoryAdapter(HistoryActivity.this, history);
        list.setAdapter(myAdapter);
    }

    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub

        try {

            HttpClient httpClient = new DefaultHttpClient();

            HttpPost httpRequest = new HttpPost(

                    "http://myurl");
            httpRequest.setHeader("Content-Type", "application/json");
            SharedPreferences mmm = getSharedPreferences(
                    "MyPref", MODE_PRIVATE);

            String logempid = mmm.getString("id", null);

            JSONObject json = new JSONObject();

            json.put("empid", logempid);

            Log.e("JSON Object", json.toString());

            StringEntity se = new StringEntity(json.toString());

            se.setContentEncoding("UTF-8");
            se.setContentType("application/json");

            httpRequest.setEntity(se);
            HttpResponse httpRes = httpClient.execute(httpRequest);

            java.io.InputStream inputStream = httpRes.getEntity()
                    .getContent();
            InputStreamReader inputStreamReader = new InputStreamReader(
                    inputStream);

            BufferedReader reader = new BufferedReader(inputStreamReader);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            inputStream.close();
            strServerResponse = sb.toString();
            Log.e("Server Response", "" + strServerResponse.toString());

            if (strServerResponse != null) {
                try {

                    JSONArray arr = new JSONArray(strServerResponse);

                    for (int k = 0; k < arr.length(); k++) {

                        JSONObject jsonObj1 = arr.getJSONObject(k);

                        pojo = new Pojo();
                        date = jsonObj1.optString("login_date");
                        inTime = jsonObj1.optString("login_time");
                        outTime = jsonObj1.optString("logout_time");

                        Log.e("login time from server",""+inTime);
                        Log.e("login out from server",""+outTime);
                        Log.e("login date from server",""+date);
                        pojo.setDate(date);
                        pojo.setLoginTime(inTime);
                        pojo.setLogoutTime(outTime);

                        JSONArray subArrayLat = jsonObj1.getJSONArray("lati_long");
                        for (int i = 0; i < subArrayLat.length(); i++) {
                            String lat = subArrayLat.getJSONObject(i).getString("Latitude").toString();
                            String loong = subArrayLat.getJSONObject(i).getString("Longitude").toString();
                            Log.e("jsonarray lat", "" + lat);
                            Log.e("jsonarray longg", "" + loong);
                            pojo.setLat(lat);
                            pojo.setLong(loong);
                        }

                        history.add(pojo);
                    }

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

这是适配器。

 public class HistoryAdapter extends BaseAdapter {
private Context activity;
TextView tv_date;
TextView tv_loginTime;
TextView tv_logoutTime;
TextView tv_details;
Pojo pojo;
ArrayList<Pojo> list;
private ArrayList<Pojo> arraylist = null;
public static LayoutInflater inflater;
private Context context;

public HistoryAdapter(Context context) {
    this.context = context;
}


public HistoryAdapter(Context a, ArrayList<Pojo> history) {
    // TODO Auto-generated constructor stub
    activity = a;
    list = history;
    inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    this.arraylist = new ArrayList<Pojo>();
    this.arraylist.addAll(list);

}

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return list.size();
}

@Override
public Object getItem(int position) {
    // TODO Auto-generated method stub
    return list.get(position);
}

@Override
public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View v = convertView;


    v = inflater.inflate(R.layout.history_item, parent, false);
    pojo = list.get(position);
    tv_date = (TextView) v.findViewById(R.id.historyDate);
    tv_loginTime = (TextView) v.findViewById(R.id.historyLoginTime);
    tv_logoutTime = (TextView) v.findViewById(R.id.historyLogoutTime);
    tv_details = (TextView) v.findViewById(R.id.historyDetails);

    tv_date.setText(pojo.getDate());
    tv_loginTime.setText(pojo.getLoginTime());
    tv_logoutTime.setText(pojo.getLogoutTime());
    final String lat = pojo.getLat().toString();
    String longg = pojo.getLong().toString();
    Log.e("adapter latitude", "" + lat);
    Log.e("adapter longitude", "" + longg);
    tv_details.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(context, MapActivity.class);
            i.putExtra("lat", "" + lat);
            i.putExtra("longg", "+longg");
            context.startActivity(i);
        }
    });

    return v;

}

 }

这是 JSON 数据

[
  {
    "login_time": "10:30:28",
    "logout_time": "10:31:47",
    "login_date": "2015- 09-30",
    "lati_long": [
      {
        "date_time": "2015:09:30  11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:52",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:17:16",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      }
    ]
  },
  {
    "login_time": "10:42:56",
    "logout_time": "10:44:41",
    "login_date": "2015-09-30",
    "lati_long": [
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:52",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:17:16",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:52",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:17:16",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      }
    ]
  }
]

这里有什么问题吗？请帮帮我。

【问题讨论】：

尝试创建 Pojo pojo；内循环
@Rajesh 它在循环内
尝试在 onCreate 方法中设置适配器
put final Pojo pojo = list.get(position);在 getview 本地并检查
你可以添加示例 Json 数据和 listView 的示例图片吗？

标签： android json android-listview baseadapter

【解决方案1】：

您已声明您的 CustomObject Pojo's 变量是全局变量。将其声明为局部变量

for (int k = 0; k < arr.length(); k++) {

         JSONObject jsonObj1 = arr.getJSONObject(k);
         Pojo pojo = new Pojo();
         date = jsonObj1.optString("login_date");
         inTime = jsonObj1.optString("login_time");
         outTime = jsonObj1.optString("logout_time");

         Log.e("login time from server",""+inTime);
         Log.e("login out from server",""+outTime);
         Log.e("login date from server",""+date);
         pojo.setDate(date);
         pojo.setLoginTime(inTime);
         pojo.setLogoutTime(outTime);

         JSONArray subArrayLat = jsonObj1.getJSONArray("lati_long");
         for (int i = 0; i < subArrayLat.length(); i++) {
                 String lat = subArrayLat.getJSONObject(i).getString("Latitude").toString();
                 String loong = subArrayLat.getJSONObject(i).getString("Longitude").toString();
                 Log.e("jsonarray lat", "" + lat);
                 Log.e("jsonarray longg", "" + loong);
                 pojo.setLat(lat);
                 pojo.setLong(loong);
          }

         history.add(pojo);
}

【讨论】：

【解决方案2】：

pojo = new Pojo();

应该像Pojo pojo = new Pojo();这样在for循环中声明

【讨论】：

【解决方案3】：

首先在myAdapter = new HistoryAdapter(HistoryActivity.this, history);这一行检查历史记录是否有正确的数据（不一样等）。

其次，编辑你的适配器的getView函数

替换这个：

View v = convertView;
v = inflater.inflate(R.layout.history_item, parent, false);

到这里：

View v = convertView;
if(convertView == null) {
   v = inflater.inflate(R.layout.history_item, parent, false);
}

统一更新： 替换这个：

 inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

到这里：

inflater = LayoutInflater.from(a);

请回复结果

【讨论】：

如何查看history是否有数据？
您可以使用断点并在 Watches 窗口中查看变量值。

【解决方案4】：

我发现了你的问题。

初始/外部JSONArray只有1 JSONObject如下图

[
  { // object 1 start
    "login_time": "10:30:28",
    "logout_time": "10:31:47",
    "login_date": "2015- 09-30",
    "lati_long": [
      {
        "date_time": "2015:09:30  11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:14:53",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:01",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:15",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:15:52",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      },
      {
        "date_time": "2015:09:30 11:17:16",
        "Latitude": "21.121776",
        "Longitude": "79.047563"
      }
    ]
  } // object 1 end
]

因此，您的外部 for 循环 for (int k = 0; k < arr.length(); k++) { 仅被调用一次，因此您的列表视图中仅提供 1 项。

下面还评论了您只看到最新的 long 和 lat 值的原因

for (int i = 0; i < subArrayLat.length(); i++) {
    String lat = subArrayLat.getJSONObject(i).getString("Latitude").toString();
    String loong = subArrayLat.getJSONObject(i).getString("Longitude").toString();
    Log.e("jsonarray lat", "" + lat);
    Log.e("jsonarray longg", "" + loong);

    // These two are called everytime but set the same pojo field
    // The result is that at the end of the loop, only the last set value is retained
    pojo.setLat(lat);
    pojo.setLong(loong);
}

这样你就有了一个具有最新 long 和 lat 值的 pojo 对象。

按照我认为您想要实现的目标，我会说使用从解析服务器响应中的内部 json 数组获得的 'sub'arraylist 来填充您的列表视图。

更新 - 更具体的答案

在内部 for 循环中创建 pojo

if (strServerResponse != null) {
    try {

    JSONArray arr = new JSONArray(strServerResponse);

    for (int k = 0; k < arr.length(); k++) {

        JSONObject jsonObj1 = arr.getJSONObject(k);

        // Comment these out:

        //1 pojo = new Pojo();
        date = jsonObj1.optString("login_date");
        inTime = jsonObj1.optString("login_time");
        outTime = jsonObj1.optString("logout_time");

        Log.e("login time from server",""+inTime);
        Log.e("login out from server",""+outTime);
        Log.e("login date from server",""+date);
        //2 pojo.setDate(date);
        //3 pojo.setLoginTime(inTime);
        //4 pojo.setLogoutTime(outTime);

        JSONArray subArrayLat = jsonObj1.getJSONArray("lati_long");
        for (int i = 0; i < subArrayLat.length(); i++) {

            // And put them here

            pojo = new Pojo();

            pojo.setDate(date);
            pojo.setLoginTime(inTime);
            pojo.setLogoutTime(outTime);

            String lat = subArrayLat.getJSONObject(i).getString("Latitude").toString();
            String loong = subArrayLat.getJSONObject(i).getString("Longitude").toString();
            Log.e("jsonarray lat", "" + lat);
            Log.e("jsonarray longg", "" + loong);
            pojo.setLat(lat);
            pojo.setLong(loong);

            // Same with this too
            history.add(pojo);
        }

        // history.add(pojo);
    }
}

【讨论】：

我必须在列表视图中显示 login_time、logout_time、login_date。这些条目有多个
更新了我的答案以反映快速修复
应该的。我检查了你代码的每一行，这是唯一相关的问题。您是否在进行其他一些更改后进行了此更改？将您的代码恢复为您发布问题时的状态并尝试一下。

【解决方案5】：

将此代码放入您的 getView()

View v = convertView;
    ViewHolder holder;

    v = inflater.inflate(R.layout.history_item, parent, false);
    if(v==null)
    {
        holder=new ViewHolder();
        pojo = list.get(position);
        holder.date = (TextView) v.findViewById(R.id.historyDate);
        holder.logintime = (TextView) v.findViewById(R.id.historyLoginTime);
        holder.lougouttime = (TextView) v.findViewById(R.id.historyLogoutTime);
        holder.details = (TextView) v.findViewById(R.id.historyDetails);
        v.setTag(holder);
    }else{
        holder=(ViewHolder)v.getTag();
    }
    holder.date.setText(pojo.getDate());
    holder.logintime.setText(pojo.getLoginTime());
    holder.lougouttime.setText(pojo.getLogoutTime());
    final String lat = pojo.getLat().toString();
    String longg = pojo.getLong().toString();
    Log.e("adapter latitude", "" + lat);
    Log.e("adapter longitude", "" + longg);
    holder.details .setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent i = new Intent(context, MapActivity.class);
            i.putExtra("lat", "" + lat);
            i.putExtra("longg", "+longg");
            context.startActivity(i);
        }
    });

    return v;

视图持有者类

protected  class ViewHolder{
        TextView date,logintime,lougouttime,details;

    }

将此粘贴到您的适配器类中

【讨论】：

【解决方案6】：

在你的情况下应该有一些改变

第一 [Pojo类]

更改 Pojo 类定义以将纬度和经度存储在列表中

class Pojo{
   List<String> lat;
   List<String> longi;

   private List<String> getLat(){
       return this.lat;
   }

   private List<String> getLongi(){
       return this.longi;  
   }

   private void setLat(List<String> lat){
     this.lat = lat;
   }

   private void setLongi(List<String> longi){
    this.longi = longi;

   }

第二[For循环逻辑]

List<String> lati = new ArrayList<String>();
List<String> longi = new ArrayList<String>();
  for (int i = 0; i < subArrayLat.length(); i++) {
         String lat = subArrayLat.getJSONObject(i).getString("Latitude").toString();
         String loong = subArrayLat.getJSONObject(i).getString("Longitude").toString();
         lati.add(lat);
         longi.add(loong);
   }
    pojo.setLat(lati);//adding latitude list
    pojo.setLongi(longi); //adding longitude list

第三 [内部getview]

通过以下方式访问这些列表

List<String> lat = pojo.getLat();
List<String> longg = pojo.getLongi();

希望对您有所帮助！

【讨论】：

@DroidwalaThanku...但我在 lati.add(lat) 处遇到指针异常；
只需使用.. List lati = new ArrayList() & List longi = new ArrayList; ...在答案中完成编辑:)
当你说它不工作时..你在 getview 中使用新的纬度和长列表值吗？
你能发布你的代码吗..你是如何在 onclick 中使用它的？
让我们continue this discussion in chat。