Develop Reference

ListView in Fragment not displayed in MainActivity

I am getting data from this API and have parsed it into a listview within a fragment. However, I can't seem to get it displayed on the Main Activity. Can anyone point me in the right direction please?
EDIT1: The layout files can be found here.
Main Activity:
package com.example.szen95.meddict;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends ActionBarActivity {
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}
SearchFragment:
package com.example.szen95.meddict;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.SimpleAdapter;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class SearchFragment extends ListFragment {
//
// #Override
// protected void onCreate(Bundle savedInstanceState) {
// super.onCreate(savedInstanceState);
// setContentView(R.layout.activity_search_fragment);
// if (savedInstanceState == null) {
// getSupportFragmentManager().beginTransaction()
// .add(R.id.container, new SearchFragment())
// .commit();
// }
// }
private ProgressDialog pDialog;
// URL to get contacts JSON
private static String url = "http://dailymed.nlm.nih.gov/dailymed/services/v2/drugclasses.json";
// JSON Node names
private static final String TAG_DATA = "data";
private static final String TAG_CODE = "code";
private static final String TAG_CODING_SYSTEM = "codingsystem";
private static final String TAG_TYPE = "type";
private static final String TAG_NAME = "name";
// contacts JSONArray
JSONArray data = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> dataList = new ArrayList<HashMap<String, String>>();
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
// Retrieving the currently selected item number
int position = getArguments().getInt("position");
// Creating view correspoding to the fragment
View v = inflater.inflate(R.layout.activity_search_fragment, container, false);
// Updating the action bar title
// getActivity().getActionBar().setTitle(options[position]);
// Calling async task to get json
new GetData().execute();
return v;
}
/**
* Async task class to get json by making HTTP call
* */
private class GetData extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(getActivity());
//
pDialog.setMessage("Please wait...");
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
data = jsonObj.getJSONArray(TAG_DATA);
// looping through All Contacts
for (int i = 0; i < data.length(); i++) {
JSONObject c = data.getJSONObject(i);
String code = c.getString(TAG_CODE);
String codingsystem = c.getString(TAG_CODING_SYSTEM);
String type = c.getString(TAG_TYPE);
String name = c.getString(TAG_NAME);
;
// tmp hashmap for single contact
HashMap<String, String> data = new HashMap<String, String>();
// adding each child node to HashMap key => value
data.put(TAG_CODE, code);
data.put(TAG_CODING_SYSTEM, codingsystem);
data.put(TAG_TYPE, type);
data.put(TAG_NAME, name);
// adding contact to contact list
dataList.add(data);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
SimpleAdapter adapter = new SimpleAdapter(getActivity(), dataList,
R.layout.list_item, new String[] { TAG_NAME, TAG_CODE}, new int[] { R.id.name,
R.id.code});
setListAdapter(adapter);
}
}
}

Un comment the onCreate method in searchFragment because your fragment is not inflating any layout

Fragments can be put into a layout using FragmentManager.
Add replace onCreate of your MainActivity with following.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fts = fragmentManager.beginTransaction();
Fragment fragment = new SearchFragment();
String fragmentTag = "SearchFragment";
fts.add(R.id.main_container, fragment, fragmentTag);
fts.commit();
}
Change your layout_activity_main.xml to following. You don't need a listview here. Just make sure you have a layout container main_container to place your fragment in.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<FrameLayout android:id="#+id/main_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
</FrameLayout>
<!-- Main ListView
Always give id value as list(#android:id/list)
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:divider="#null"/>
-->
</LinearLayout>

I think your problem is caused by Jason parsing.
private static final String TAG_CODING_SYSTEM = "codingSystem";
Jason key is case sensitive. But please try to debug by yourself next time, it's the only way to become a better coder. Cheers!

NullPointerException in Fragment's OnCreateView() [duplicate]

This question already has answers here:
fragment.onCreateView causes null pointer exception
(3 answers)
Closed 7 years ago.
I get a NullPointerException at Fragement's OnCreateView() methods. I've tried several things, but the error keeps showing up. I think the error comes from the listview.
This is my code:
package com.imptmd.charliemacdonald.desleutelaar;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
public class SlotenFragment extends ListFragment {
private ProgressDialog nDialog;
// URL to get contacts JSON
private static String url = "http://charlenemacdonald.com/sloten.json";
// JSON Node names
private static final String TAG_SLOTEN = "slotenlijst";
private static final String TAG_SLOT = "Slot";
// contacts JSONArray
JSONArray sloten= null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> slotenLijst;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View rootView = inflater.inflate(R.layout.fragment_sloten, container, false);
slotenLijst = new ArrayList<HashMap<String, String>>();
ListView lv = (ListView) getView().findViewById(android.R.id.list);
// Listview on item click listener
lv.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String Slot = ((TextView) rootView.findViewById(R.id.textviewslotnaam))
.getText().toString();
// Starting single contact activity
Intent in = new Intent(getActivity().getApplicationContext(),
SlotInfoScherm1.class);
in.putExtra(TAG_SLOT, Slot);
startActivity(in);
}
});
return rootView;
// Calling async task to get json
}
/**
* Async task class to get json by making HTTP call
* */
private class GetSloten extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
nDialog = new ProgressDialog(getActivity());
nDialog.setMessage("Even geduld a.u.b., studenten worden geladen...");
nDialog.setCancelable(false);
nDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
// Creating service handler class instance
ServiceHandler sh = new ServiceHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);
if (jsonStr != null) {
try {
JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
sloten = jsonObj.getJSONArray(TAG_SLOTEN);
// looping through All Contacts
for (int i = 0; i < sloten.length(); i++) {
JSONObject c = sloten.getJSONObject(i);
String Slot = c.getString(TAG_SLOT);
// tmp hashmap for single contact
HashMap<String, String> sloten = new HashMap<String, String>();
// adding each child node to HashMap key => value
sloten.put(TAG_SLOT, Slot);
// adding contact to contact list
slotenLijst.add(sloten);
}
} catch (JSONException e) {
e.printStackTrace();
}
} else {
Log.e("ServiceHandler", "Couldn't get any data from the url");
}
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (nDialog.isShowing())
nDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(getActivity(), slotenLijst,
R.layout.sloten_info, new String[] { TAG_SLOT}, new int[] { R.id.textviewslotnaam});
setListAdapter(adapter);
}
}
}
Thanks in advance!

In your onCreateView() method, replace
ListView lv = (ListView) getView().findViewById(android.R.id.list);
with
ListView lv = (ListView) rootView.findViewById(android.R.id.list);
The getView() method cannot be called before onCreateView() returns, as getView() in effect returns the View created by onCreateView().

Call findViewById() on the rootView you just inflated, not on the activity.
The view hierarchy you just inflated is not yet a part of the activity view hierarchy.

setMediaController in onCreate error

I have 2 simple working apps that I'm trying to combine. #1 plays a video in a videoview from a URL that I specified, and #2 loads information from a database. I'm just trying to put the videoview in the same area as the information loading from the database.
The videoview appears in the right place, but the app crashes when I add this code anywhere in onCreate:
// **NEW VIDEOVIEW CODE**
VideoView vid = (VideoView) findViewById(R.id.videoView);
Uri video = Uri.parse(MOVIE_URL);
vid.setMediaController(new MediaController(this));
vid.setVideoURI(video);
vid.start();
vid.requestFocus();
With trial and error I determined that it crashes starting at the 'setMediaController' line. Here is the onCreate(which works fine without the above code, other than the blank videoview obviously):
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
Here is the logcat:
05-10 15:33:29.064: I/Adreno-EGL(7866): <qeglDrvAPI_eglInitialize:320>: EGL 1.4 QUALCOMM Build: I0404c4692afb8623f95c43aeb6d5e13ed4b30ddbDate: 11/06/13
05-10 15:33:29.084: D/OpenGLRenderer(7866): Enabling debug mode 0
05-10 15:33:30.214: D/AndroidRuntime(7866): Shutting down VM
05-10 15:33:30.214: W/dalvikvm(7866): threadid=1: thread exiting with uncaught exception (group=0x41898ba8)
05-10 15:33:30.214: E/AndroidRuntime(7866): FATAL EXCEPTION: main
05-10 15:33:30.214: E/AndroidRuntime(7866): Process: com.example.androidhive, PID: 7866
05-10 15:33:30.214: E/AndroidRuntime(7866): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.androidhive/com.example.androidhive.AllProductsActivity}: java.lang.NullPointerException
05-10 15:33:30.214: E/AndroidRuntime(7866): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
In summary, I'm trying to figure out if I'm going about these entirely wrong or if there is a way to include this code without crashing. Thanks!!
EDIT I apologize for not posting these earlier, I just didn't want to overwhelm people.
Here is my list_item.xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<!-- Product id (pid) - will be HIDDEN - used to pass to other activity -->
<TextView
android:id="#+id/pid"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:visibility="gone" />
<!-- Name Label -->
<TextView
android:id="#+id/name"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="6dip"
android:paddingLeft="6dip"
android:textSize="17dip"
android:textStyle="bold" />
<TextView
android:id="#+id/description"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:paddingTop="6dip"
android:paddingLeft="6dip"
android:textSize="17dip"
android:textStyle="bold" />
<VideoView
android:id="#+id/videoView"
android:layout_width="100dp"
android:layout_height="100dp"
/>
</LinearLayout>
Here is my all_products.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<!-- Main ListView
Always give id value as list(#android:id/list)
-->
<ListView
android:id="#android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content"/>
</LinearLayout>
And finally... here is my ENTIRE AllProductsActivity.java file:
package com.example.androidhive;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.MediaController;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.VideoView;
public class AllProductsActivity extends ListActivity {
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// get video url
private static final String MOVIE_URL ="http://mywebsite.com/mycameraapp/android_connect/videos/testvideo.mkv";
// url to get all products list
private static String url_all_products = "http://mywebsite.com/mycameraapp/android_connect/get_all_products.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_DESCRIPTION = "description";
// products JSONArray
JSONArray products = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.all_products);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = getListView();
// **NEW VIDEOVIEW CODE**
VideoView vid = (VideoView) findViewById(R.id.videoView);
Uri video = Uri.parse(MOVIE_URL);
vid.setMediaController(new MediaController(this));
vid.setVideoURI(video);
vid.start();
vid.requestFocus();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// getting values from selected ListItem
String pid = ((TextView) view.findViewById(R.id.pid)).getText()
.toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivityForResult(in, 100);
}
});
}
// Response from Edit Product Activity
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
// if result code 100
if (resultCode == 100) {
// if result code 100 is received
// means user edited/deleted product
// reload this screen again
Intent intent = getIntent();
finish();
startActivity(intent);
}
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(AllProductsActivity.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(url_all_products, "GET", params);
// Check your log cat for JSON reponse
Log.d("All Products: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
products = json.getJSONArray(TAG_PRODUCTS);
// looping through All Products
for (int i = 0; i < products.length(); i++) {
JSONObject c = products.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_PID);
String name = c.getString(TAG_NAME);
String description = c.getString(TAG_DESCRIPTION);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_PID, id);
map.put(TAG_NAME, name);
map.put(TAG_DESCRIPTION, description);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getApplicationContext(),
NewProductActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
AllProductsActivity.this, productsList,
R.layout.list_item, new String[] { TAG_PID, TAG_NAME, TAG_DESCRIPTION},
new int[] { R.id.pid, R.id.name, R.id.description });
// updating listview
setListAdapter(adapter);
}
});
}
}
}

You are receiving the error because the VideoView element is not available in the all_products.xml file.
What you need to do is create a ListAdapter and have the getView() method of the list adapter reference your list_item.xml layout file. That is the file that contains the VideoView.

JSON exception to parse photo_refrence from Google places api

I have made a json android application, to show the reference of the photos, in a list view, but it gives me an error
my code is\
package com.example.jsonapp;
import java.util.ArrayList;
import java.util.HashMap;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Context;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
public class MainActivity extends ListActivity {
// url to make request
private static String url = "https://maps.googleapis.com/maps/api/place/nearbysearch /json?location=mylatandlong&radius=5000&types=restaurant&sensor=false&key=myownkey";
// JSON Node names
private static final String TAG_RESULTS = "results";
private static final String TAG_PHOTOS = "photos";
private static final String TAG_REFRENCE = "photo_reference";
JSONArray results = null;
JSONArray photos = null;
Context c;
// Progress dialog
ProgressDialog pDialog;
ArrayList<HashMap<String, String>> contactList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
new LaodPhotos().execute(TAG_REFRENCE);
//ListView lv = getListView();
}//the end of on create
public class LaodPhotos extends AsyncTask<String, String, String>{
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Loading profile ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
#Override
protected String doInBackground(String... arg0) {
contactList = new ArrayList<HashMap<String, String>>();
JSONParser jParser = new JSONParser();
JSONObject json = jParser.getJSONFromUrl(url);
try{
results = json.getJSONArray(TAG_RESULTS);
photos = json.getJSONArray(TAG_PHOTOS);
for(int i=0; i<results.length(); i++){
JSONObject c = results.getJSONObject(i);
if(c != null){
for(int j=0; j<photos.length(); j++){
JSONObject pc = photos.getJSONObject(j);
String photo = pc.getString(TAG_REFRENCE);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_REFRENCE, photo);
contactList.add(map);
}
}
}
}catch(JSONException e){
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
ListAdapter adapter = new SimpleAdapter(c, contactList, R.layout.list_item,
new String[]{TAG_REFRENCE}, new int[]{R.id.photoRef});
setListAdapter(adapter);
}//end of run method
});//end of runOnUiThread
}//end of onPost method
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
The log cat\
E/AndroidRuntime(23042): java.lang.NullPointerException
E/AndroidRuntime(23042): at android.widget.SimpleAdapter.(SimpleAdapter.java:85)
would any one help me to know how to make this succeed, I want to have the photo_reference
to be able to show it as Image, but first need to know how to have the photo_reference?!

you forget to initialize c Context instance with Activity Context before passing it to SimpleAdapter.so pass Activity Context to Adapter as:
ListAdapter adapter = new SimpleAdapter(MainActivity.this,
contactList, R.layout.list_item,
new String[]{TAG_REFRENCE},
new int[]{R.id.photoRef});
MainActivity.this.setListAdapter(adapter);
and onPostExecute method already run on UI Thread then no need to use runOnUiThread for updating UI elements form onPostExecute

error with calling class that extends asynctask to run it

I'm using class that extends AsyncTask but I have error at the line that executes the class
I couldn't figure it out
here is the class that includes my main class and the class that extends AsyncTask
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.example.androidhive.library.JSONParser;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.topics_list);
// Hashmap for ListView
TopicsList = new ArrayList<HashMap<String, String>>();
**// Loading products in Background Thread
new LoadAllTopics().execute();**
// Get listview
ListView lv = getListView();
// on seleting single product
// launching Edit Product Screen
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// getting values from selected ListItem
String tid = ((TextView) view.findViewById(R.id.tid)).getText()
.toString();
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllTopics extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(Topics_list.this);
pDialog.setMessage("Loading products. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
/**
* getting All products from url
* */
protected String doInBackground(String... args) {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
// getting JSON string from URL
JSONObject json = jParser.makeHttpRequest (url_all_topics, "GET", params);
// Check your log cat for JSON reponse
Log.d("All topics: ", json.toString());
try {
// Checking for SUCCESS TAG
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// products found
// Getting Array of Products
topics = json.getJSONArray(TAG_TOPICS);
// looping through All Products
for (int i = 0; i < topics.length(); i++) {
JSONObject c = topics.getJSONObject(i);
// Storing each json item in variable
String id = c.getString(TAG_TOPICSID);
String topict = c.getString(TAG_TOPICTITLE);
String username = c.getString(TAG_TOPICAUTHOR);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_TOPICSID, id);
map.put(TAG_TOPICTITLE, topict);
map.put(TAG_TOPICAUTHOR, username);
// adding HashList to ArrayList
TopicsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
/* Intent i = new Intent(getApplicationContext(),
NewProductActivity.class);
// Closing all previous activities
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(i);*/
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog after getting all products
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
Topics_list.this, TopicsList,
R.layout.list_item, new String[] { TAG_TOPICSID,TAG_TOPICTITLE,
TAG_TOPICAUTHOR},
new int[] { R.id.tid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
} });}}
the error is at the bold line
really appreciate your help

In Java you need to write the method inside the class. Put the onCreate inside Class.
public class MainActivity extends Activity {
public void onCreate(Bundle savedInstanceState) {
.....
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// getting values from selected ListItem
String tid = ((TextView) view.findViewById(R.id.tid)).getText()
.toString();
}
});
.........
}
private class LoadAllTopics extends AsyncTask<String, String, String> {
.....
}
}