JSON解析数据中ListFragment不显示 [英] JSON Parsed Data not showing in ListFragment
问题描述
我使用了MySQL数据库和PHP使用它连接到我的Android应用程序。我在表中增加了一个样本行和PHP脚本正在返回JSON。我已经尽了全力在解析JSON,并在列表中显示它。但它似乎并不奏效。能够运行应用程序 - 但不显示的内容 - 只显示对话框。这似乎在活动的情况下工作 - 应该怎样进行更改,使之成为一个片段工作。这是我的LogCat中,当我打开片段 - http://prntscr.com/3f6k0a 。
I have used a MYSQL Database and connected it to my Android App using PHP. I added a sample row in the table and the PHP Script is returning JSON. I have tried my best in parsing the JSON and displaying it in a list. But it does not seem to be working. Able to run the App - But does not display content - Only shows the Dialog. It seems to work in Case of an Activity - What changes should be made to make it work for a Fragment. Here is my LogCat when I open up the fragment - http://prntscr.com/3f6k0a .
package com.example.socbeta;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
public class events extends ListFragment {
private ProgressDialog pDialog;
private static final String READ_EVENTS_URL ="http://socapptest.comoj.com/socbeta/events.php";
//JSON IDS:
private static final String TAG_SUCCESS = "success";
private static final String TAG_EventName = "EventName";
private static final String TAG_POSTS = "posts";
private static final String TAG_ID = "ID";
private static final String TAG_DATE = "Date";
private static final String TAG_MESSAGE = "message";
private JSONArray mEvents = null;
private ArrayList<HashMap<String, String>> mEventList;
public events(){}
@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.events, container, false);
}
@Override
public void onResume() {
// TODO Auto-generated method stub
super.onResume();
//loading the comments via AsyncTask
new LoadEvents().execute();
}
public void updateJSONdata() {
mEventList = new ArrayList<HashMap<String, String>>();
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(READ_EVENTS_URL);
try {
mEvents = json.getJSONArray(TAG_POSTS);
for (int i = 0; i < mEvents.length(); i++) {
JSONObject c = mEvents.getJSONObject(i);
String EventName = c.getString(TAG_EventName);
String content = c.getString(TAG_MESSAGE);
String Date = c.getString(TAG_DATE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_EventName, EventName);
map.put(TAG_MESSAGE, content);
map.put(TAG_DATE, Date);
mEventList.add(map);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
private void updateList() {
ListAdapter adapter = new SimpleAdapter(getActivity(), mEventList,
R.layout.list_item,
new String[] { TAG_EventName, TAG_MESSAGE,TAG_DATE },
new int[] { R.id.eventname, R.id.message,R.id.date });
setListAdapter(adapter);
ListView lv = getListView();
lv.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
});
}
public class LoadEvents extends AsyncTask<Void, Void, Boolean> {
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
pDialog.setMessage("Loading Events...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected Boolean doInBackground(Void... arg0) {
updateJSONdata();
return null;
}
@Override
protected void onPostExecute(Boolean result) {
super.onPostExecute(result);
pDialog.dismiss();
updateList();
}
}
}
编辑:
得到了我的code工作。问题是用JSON结构。我没有正确导航,这给了我一个错误消息没有价值。对于其他人谁可能有同样的问题 - 请记住,当你有{在你的JSON,您使用JSONArray当你有[您使用的JSONObject。你需要通过你的JSON明智导航模块。
Got my code to work. The Problem was with the JSON Structure. I did not Navigate properly and this gave me a "No Value for message" Error. For others who might be having same issues - Remember that when you have { in your JSON , you use JSONArray and when you have [ you use JSONObject. You need to navigate module wise through your JSON.
推荐答案
试试这个code
通JSON字符串于该方法。它会工作
pass json string to this method . it will work
公开的JSONObject getJSONfromURL(字符串URL)
public JSONObject getJSONfromURL(String url)
{
InputStream is = null;
JSONObject jObj = null;
String json = "";
尝试{
// defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpGet httpget= new HttpGet(url);
HttpResponse httpResponse = httpClient.execute(httpget);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
} catch (Exception e) {
e.printStackTrace();
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
}
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e("JSON Parser", "Error parsing data " + e.toString());
}
return jObj;
}
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