How to set onCLickListner for dynamic ListView - android

I am working on an android project. I want to add onClick event to listView so that whenever someone clicks on any item in the ListView new fragment showing further details is displayed.I am using Mysql database.
package com.example.festipedia_logo;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import com.actionbarsherlock.app.SherlockFragment;
import com.actionbarsherlock.app.SherlockListFragment;
import com.example.festipedia_logo.Searchpage.LoadAllProducts;
//import com.example.connection.disp;
import android.app.Activity;
import android.app.ListActivity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Spinner;
import android.widget.TextView;
public class details1 extends SherlockFragment {
ArrayAdapter<String> adapter;
String[] city;
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
EditText b;
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
private static String url_all_products = "http://192.168.43.185:8080/festipedia/get_all_products.php";
Button a;
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCTS = "products";
private static final String TAG_NAME = "eventname";
// products JSONArray
JSONArray products = null;
ListView l;
Spinner spinner;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.second);
View rootView = inflater.inflate(R.layout.home2, container, false);
// setContentView(R.layout.all_products);
l = (ListView) rootView.findViewById(R.id.myListView);
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
new LoadAllProducts().execute();
return rootView;
}
/**
* Background Async Task to Load all product by making HTTP Request
* */
class LoadAllProducts extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(getActivity());
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);
// 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 name = c.getString(TAG_NAME);
//l.setFilterText(id);
// creating new HashMap
HashMap<String, String> map = new HashMap<String, String>();
// adding each child node to HashMap key => value
map.put(TAG_NAME, name);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
}
} 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
getActivity().runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), productsList,
R.layout.list_item, new String[] {
TAG_NAME},
new int[] { R.id.name });
// updating listview
l.setAdapter(adapter);
}
});
}
}
}

Try this..
Add below ItemClickListener Codes before return rootView;
l.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
// Do something
}
});

You need to use OnItemClickListener and add/replace existing fragment in the container.
l.setOnItemClickListener(new OnItemClickListener()
{
#Override
public void onItemClick(AdapterView<?> arg0, View arg1,int position, long arg3)
{
Toast.makeText(getActivity(), "Clicked at" + position, Toast.LENGTH_SHORT).show();
}
});
Also you need not have runOnUiThread in onPostExecute as it is invoked on the ui thread.
You also need to use interface as a call back to the Activity and then add/replace fragment to the container in Activity
Exmple #
How to send data from fragment to fragment within same fragment activity?

Add ItemClickListener below
l = (ListView) rootView.findViewById(R.id.myListView);
in function onCreateView();
l.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View v, int position, long id) {
// Do something
}
});

Related

Issues with Listview in a Fragment in Android

I have a ListView in a ListFragment and in the code I wrote a code that says when an item of listview is clicked, open another activity.
The problem is when I click on an item, nothing happens!
This code works fine in an Activity, but not in a Fragment.
Code:
ListView lv = (ListView) v.findViewById(android.R.id.list);
lv.setOnItemClickListener(new AdapterView.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(getActivity().getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivity(in);
}
});
I replaced this code :
ListView lv = (ListView) v.findViewById(android.R.id.list);
with :
ListView lv = getListView();
Because it was giving me
content view not yet created
in logcat.
All the code:
package rappage.rapfarsi.media.appteam;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.StrictMode;
import android.support.annotation.Nullable;
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.apache.http.NameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class tab1 extends ListFragment {
static final String url_all_products = "http://aliak.xzn.ir/rap/get_all_products.php";
// Progress Dialog
private ProgressDialog pDialog;
// Creating JSON Parser object
JSONParser jParser = new JSONParser();
ArrayList<HashMap<String, String>> productsList;
// url to get all products list
final String TAG_SUCCESS = "success";
final String TAG_PRODUCTS = "products";
final String TAG_PID = "pid";
final String TAG_NAME = "name";
// JSON Node names
// products JSONArray
JSONArray products = null;
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.tab_1, container, false);
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
// Hashmap for ListView
productsList = new ArrayList<HashMap<String, String>>();
// Loading products in Background Thread
new LoadAllProducts().execute();
// Get listview
ListView lv = (ListView) v.findViewById(android.R.id.list);
lv.setOnItemClickListener(new AdapterView.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(getActivity().getApplicationContext(),
EditProductActivity.class);
// sending pid to next activity
in.putExtra(TAG_PID, pid);
// starting new activity and expecting some response back
startActivity(in);
}
});
return v;
}
/**
* 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(getActivity());
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);
// 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);
// adding HashList to ArrayList
productsList.add(map);
}
} else {
// no products found
// Launch Add New product Activity
Intent i = new Intent(getActivity().getApplicationContext(),
Main.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
getActivity().runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
getActivity(), productsList,
R.layout.list_item, new String[] { TAG_PID,
TAG_NAME},
new int[] { R.id.pid, R.id.name });
// updating listview
setListAdapter(adapter);
}
});
}
}
}
I hope you can help me....thanks
Extending from ListFragment you only have to redefine this method:
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
//Handle click event
}
Instead of getting the list and setting its onItemClickListener

listview doesn't appear, no errors

I am making a listview, which shows data from a server. I get no errors in LogCat, but my ListView doesn't appear. 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) rootView.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);
}
});
new GetSloten().execute();
// Calling async task to get json
return rootView;
}
/**
* 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);
}
}
}
The INTERNET permission is already added in the Manifest, just as WRITE EXTERNAL STORAGE and INTERNAL STORAGE. I get no errors in LogCat. The only error I get is in the ADB 'ADB rejected connection to client'. Is that why my ListView doesn't appear? Thanks in advance.
Hi can you update you code and test the below logic what you received.
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
// Dismiss the progress dialog
if (nDialog.isShowing())
nDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
Log.d("DataSize: ",""+slotenLijst.size());
ListAdapter adapter = new SimpleAdapter(getActivity(), slotenLijst,
R.layout.sloten_info, new String[] { TAG_SLOT}, new int[] { R.id.textviewslotnaam});
setListAdapter(adapter);
}
Let us know what you get in log cat "DataSize".
Change your onCreateView(...) to be:
#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) rootView.findViewById(android.R.id.list);
new GetSloten().execute();
// Calling async task to get json
return rootView;
}
// ListFragment implement this in default
#Override
public void onListItemClick(ListView l, View v, 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);
}
});
and your fragment layout fragment_sloten could be like:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingLeft="8dp"
android:paddingRight="8dp">
<ListView android:id="#id/android:list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#00FF00"
android:layout_weight="1"
android:drawSelectorOnTop="false"/>
... ...
</LinearLayout>
Hope this help!

I get into trouble, how to keep each listview can open their own webview?

how can I make WebView can open the fragment listview? this is my code, and i got error code in :
lv.setOnItemClickListener(new OnItemClickListener() : The method setOnItemClickListener(AdapterView.OnItemClickListener) in the type AdapterView is not applicable for the arguments (new OnItemClickListener(){})
package info.androidhive.slidingmenu;
import android.net.Uri;
import android.os.Bundle;
import android.app.Fragment;
import android.content.Intent;
import java.util.ArrayList;
import java.util.HashMap;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.ListAdapter;
import android.widget.SimpleAdapter;
import android.widget.Toast;
public class FindPeopleFragment extends Fragment {
public FindPeopleFragment(){}
protected ListView lv;
protected ListAdapter adapter;
public static final String MOVIE_DETAIL_KEY = "movie";
SimpleAdapter Adapter;
HashMap<String, String> map;
ArrayList<HashMap<String, String>> mylist;
String[] Pil;
String[] Ltn;
String[] Gbr;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.activity_pulau, container,false);
ListView lv = (ListView) rootView.findViewById(R.id.lv);
Pil = new String[] {"Pulau Gusung", "Binatang Laut Khas"};
Ltn = new String[] {"Baca Selengkapnya...", "Baca Selengkapnya..."};
Gbr = new String[] {Integer.toString(R.drawable.ic_photos),
Integer.toString(R.drawable.ic_photos),
};
mylist = new ArrayList<HashMap<String,String>>();
for (int i = 0; i < Pil.length; i++){
map = new HashMap<String, String>();
map.put("list", Pil[i]);
map.put("latin", Ltn[i]);
map.put("gbr", Gbr[i]);
mylist.add(map);
}
Adapter = new SimpleAdapter(getActivity(), mylist, R.layout.item_kepulauan,
new String[] {"list", "latin", "gbr"}, new int[] {R.id.tv_nama, R.id.tv_des, R.id.imV});
lv.setAdapter(Adapter);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
// ListView Clicked item index
int itemPosition = position;
// ListView Clicked item value
String itemValue = (String) lv
.getItemAtPosition(position);
if (position == 0) {
Intent myIntent = new Intent(getApplicationContext(),
Story.class);
startActivity(myIntent);
}else if (position == 1) {
Intent myIntent = new Intent(getApplicationContext(),
Story.class);
startActivity(myIntent);
}
// Show Alert
Toast.makeText(
getApplicationContext(),
"Position :" + itemPosition + " ListItem : "
+ itemValue, Toast.LENGTH_LONG).show();
}
});
return rootView;
}
}
The issue is because you're using a new instance of OnItemClickListener when it should be AdapterView.OnItemClickListener. You've imported AdapterView, but not the inner interface, and there is no standalone OnItemClickListener interface so the types do not line up.

load a few json elements at a time by scrollview

I have a ListFragment that contains a list of items. I would like to load say 9 items at a time and when i scroll and reach the bottom of the listview i want to load another 9 items in background.
I make 2 request to my web server:
1) to get all the item id's of the items, by a searh() method
2) to get all the item details of a specific item though its id, by getId(id) method
The version i have implemented gets all the ids and then loads all the items at once in the doInBackground method of AsyncTask and it works. and it takes very long (i dont want a button because its really ugly).
I'd like to introduce this thing about the onScrollListener so that when i first open my app, in background i get all the ids, and then i get the first 9 items and show them. then when i scroll to the end i want to load the next 9 items. How do i do this?
I have read a few posts but it not clear to me, especially due to the fact that i have 2 functions that need to be run in background, 1 function needs to be run once while the other many times and i need to keep track of which id's i getting.
I would also if possible like to add the function that if i pull the ListView a little then it should update my view.
Here is my code:
import java.util.ArrayList;
import java.util.HashMap;
import android.app.ListFragment;
import android.app.ProgressDialog;
import android.graphics.Bitmap;
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.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListView;
import android.widget.Toast;
import com.prjma.lovertech.R;
import com.prjma.lovertech.adapter.ListViewAdapter;
import com.prjma.lovertech.util.MVPFunctions;
public class CompraFragment extends ListFragment {
public ListView listView;
public ListViewAdapter adapter;
/**
* Keep track of the login task to ensure we can cancel it if requested.
*/
private DownloadTask mDownloadTask = null;
public ArrayList<HashMap<String, Object>> items;
public Bitmap icon;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
//View rootView = inflater.inflate(R.layout.fragment_compra, false);
View rootView = inflater.inflate(R.layout.fragment_compra, container, false);
// now you must initialize your list view
listView = (ListView) rootView.findViewById(android.R.id.list);
mDownloadTask = new DownloadTask();
mDownloadTask.execute((Void) null);
return rootView;
}
/**
* Represents an asynchronous login/registration task used to authenticate
* the user.
*/
public class DownloadTask extends AsyncTask<Void, Void, Boolean> {
private ProgressDialog progressDialog;
#Override
protected Boolean doInBackground(Void... params) {
// TODO: attempt authentication against a network service.
//Here i get all the id's
ArrayList<Long> ids = MVPFunctions.getMioSingolo().search();
//for each id get all its details and put it in a map
items = new ArrayList<HashMap<String, Object>>();
for(int i=0; i < ids.size(); i++){
items.add(MVPFunctions.getMioSingolo().getItem(ids.get(i)));
}
return true;
}
#Override
protected void onPreExecute(){
/*
* This is executed on UI thread before doInBackground(). It is
* the perfect place to show the progress dialog.
*/
progressDialog = ProgressDialog.show(getActivity(), "", "Downloading Content...");
}
#Override
protected void onPostExecute(final Boolean success) {
mDownloadTask = null;
// dismiss the dialog after getting all products
progressDialog.dismiss();
//showProgress(false);
if (items.get(0).get("status error")!= null){
Toast.makeText(getActivity(), "status error = " + items.get(0).get("status error"), Toast.LENGTH_LONG).show();
Log.i("status error put toast", (String) items.get(0).get("status error"));
//fai qualcosa, tipo torna indietro, ecc
}
// updating UI from Background Thread
ListViewAdapter adapter = new ListViewAdapter(getActivity(),R.layout.listview_item_row, items, icon);
// updating listview
listView.setAdapter(adapter);
}
#Override
protected void onCancelled() {
mDownloadTask = null;
//showProgress(false);
}
}
}
Adapter class:
import java.util.ArrayList;
import java.util.HashMap;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.prjma.lovertech.R;
import com.prjma.lovertech.activity.DettagliActivity;
import com.prjma.lovertech.model.Item;
public class ListViewAdapter extends ArrayAdapter<String> {
private static LayoutInflater inflater = null;
public Context context;
public int layoutResourceId;
public ArrayList<HashMap<String, Object>> items;
public Bitmap icon;
//public ImageLoader imageLoader;
public ListViewAdapter(Context context, int listviewItemRow, ArrayList<HashMap<String, Object>> items, Bitmap icon) {
// TODO Auto-generated constructor stub
super(context, listviewItemRow);
this.items = items;
this.context = context;
this.icon = icon;
}
public int getCount() {
return items.size();
}
public Item getItem(Item position) {
return position;
}
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View row = convertView;
ViewHolder viewHolder = new ViewHolder();
if (row == null) {
inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
row = inflater.inflate(R.layout.listview_item_row, null);
viewHolder.ic_thumbnail = (ImageView)row.findViewById(R.id.ic_thumbnail);
viewHolder.scadenza = (TextView)row.findViewById(R.id.tvScadenza);
viewHolder.prezzo = (TextView)row.findViewById(R.id.tvPrezzo);
viewHolder.followers = (TextView)row.findViewById(R.id.tvFollowers);
viewHolder.hProgressBar = (ProgressBar)row.findViewById(R.id.hProgressBar);
row.setTag(viewHolder);
} else {
viewHolder = (ViewHolder)row.getTag();
}
HashMap<String, Object> item = items.get(position);
viewHolder.ic_thumbnail.setImageBitmap((Bitmap) item.get("pic1m"));
viewHolder.scadenza.setText((CharSequence) item.get("scadenza"));
viewHolder.prezzo.setText((CharSequence) item.get("prezzo"));
viewHolder.followers.setText((CharSequence) item.get("followers"));
viewHolder.hProgressBar.setProgress((Integer) item.get("coefficient"));
//row.onListItemClick(new OnItemClickListener1());
row.setOnClickListener(new OnItemClickListener(position));
return row;
}
private class OnItemClickListener implements OnClickListener {
private int mPosition;
private OnItemClickListener(int position){
mPosition = position;
}
#Override
public void onClick(View arg0) {
Log.i("onListItemClickList", "Item clicked: " + mPosition);
Toast.makeText(context, "Message " + Integer.toString(mPosition), Toast.LENGTH_SHORT).show();
Intent intent = new Intent(context, DettagliActivity.class);
Bundle bundle = new Bundle();
bundle.putInt("id", mPosition);
intent.putExtras(bundle);
context.startActivity(intent);
}
}
static class ViewHolder {
public TextView prezzo;
public TextView scadenza;
public TextView followers;
public ImageView ic_thumbnail;
public ProgressBar hProgressBar;
}
}
In your adapter, check how close the user is from the bottom of the data set. When they get to the end, call a method that fetches more items from the network. I normally use a "REFRESH_THRESHOLD" integer to prefetch items before they're needed.
#Override
public View getView(int position, View convertView, ViewGroup parent) {
Item current = getItem(position);
//Pre-fetch
if(getCount() - position <= REFRESH_THRESHOLD){
//If there are more items to fetch, and a network request isn't already underway
if(is_loading == false && has_remaining_items == true){
getItemsFromNetwork();
}
}

Creating a ListView in Fragment that Retrieves Data from a Server

I've been attempting to create a ListView in a fragment that gets data from a server, but so far have been unsuccessful. I've been using the following site: Vogella for learning on how to implement ListView in a fragment, but I am having difficulties when trying to populate data from a server.
package com.example.ips_alpha;
import java.util.ArrayList;
import java.util.HashMap;
import android.util.Log;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.ListFragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TableLayout;
public class Gold_Visitors2 extends ListFragment{
//JSON Node names (level, sensorID, value)
String SPACES = "spaces"; //String array name of php
String LEVEL = "level";
String SENSORID = "sensorID";
String VALUE = "value";
//pspace JSONArray
JSONArray pspace = null;
String[] levels = new String[]{LEVEL, SENSORID, VALUE};
int [] ids = new int[]{};
private static String url = "http://www.example.com/getUsers12.php";
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
View view = inflater.inflate(R.layout.fragment_gold_visitors, null);
new MyAsyncTask().execute();
return view;
}
class MyAsyncTask extends AsyncTask<String, Integer, ArrayList<HashMap<String, String>> > {
//Hashmap for ListView
ArrayList<HashMap<String, String>> levelList = new ArrayList<HashMap<String, String>>();
#Override
protected ArrayList<HashMap<String, String>>doInBackground(String... params) {
//Creating JSON Parser instance
JSONParser jParser = new JSONParser();
//getting JSON string from URL
JSONObject json = jParser.getJSONFromUrl(url);
try {
//Getting Array of spaces
pspace = json.getJSONArray(SPACES);
//looping through all spaces
for(int i = 0; i < pspace.length(); i++){
JSONObject p = pspace.getJSONObject(i);
//Storing each json item in variable
String level = p.getString(LEVEL);
String sensorID = p.getString(SENSORID);
String value = p.getString(VALUE);
//creating new HashMap
HashMap<String, String> map = new HashMap <String, String>();
//adding each child node to HashMap Key =>
map.put(LEVEL, level);
map.put(SENSORID, sensorID);
map.put(VALUE, value);
//adding HashList to ArrayList
}
}catch(JSONException e){
e.printStackTrace();
}
return levelList;
}
#Override
protected void onPostExecute(ArrayList<HashMap<String, String>> levelList) {
ListAdapter adapter = new SimpleAdapter(getActivity(), levelList, R.layout.fragment_gold_visitors, levels, ids);
setListAdapter(adapter);
}
}
}
The following is the layout file:
<?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" >
<ListView
android:id="#id/android:list"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
Currently my app is compiling and does not crash, but when accessing the fragment that is supposed to display the ListView, it's blank. I believe I'm messing up in the ASyncTask and the adapter, any help would greatly be appreciated.
You return levelList in doInBackground, but you never added any items to it from the retrieved JSON. All you have is an empty ArrayList, so the ListView is empty.

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