How not to affect the UI when executing an AsyncTask? - android

I have an issue, which is not that big, but to the user it is bad.
The app basically gets the user's input of some place and, when the user clicks on the button, a URL to the Google API with the place on its parameter is sent to an AsyncTask, where it sends this URL via HttpGet and is returned a JSONArray with everything needed. The problem is, when I click on the button and the internet is not that good, the button seems to "freeze" like this:
My activity code is below:
public class MainActivity extends Activity{
...
protected void onCreate(Bundle savedInstanceState){...}
public void onResume()}
btnSearch.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
String search = txtSearch.getText().toString();
try{
List<Location> locations = new SearchTask(MainActivity.this).execute(strSearch).get();
if(locations != null){
ArrayAdapter<Location> adapter = new ArrayAdapter<Location>(MainActivity.this, android.R.layout.simple_list_item_1, locations);
listView.setAdapter(adapter);
...
}
}
}
}
}
}
My AsyncTask class code is below:
public class SearchTask extends AsyncTask<String, Void, List<Location>>{
...
protected List<Location> doInBackground(String... params){
if(isNetworkAvailable()){
HttpGet httpGet = null;
HttpClient client = null;
HttpResponse response = null;
StringBuilder builder = null;
try{
String param = URLDecoder.decode(params[0], "UTF-8").replace(" ", "%20");
httpGet = new HttpGet("http://maps.googleapis.com/maps/api/geocode/json?address=" + param + "&sensor=false");
client = new DefaultHttpClient();
builder = new StringBuilder();
}
catch(UnsupportedEncodingException e){
Log.i("Error", e.getMessage());
}
try{
response = client.execute(httpGet);
HttpEntity entity = response.getEntity();
InputStream stream = entity.getContent();
BufferedReader br = new BufferedReader(new InputStreamReader(stream, "UTF-8"));
int val;
while((val = br.read()) != -1){
builder.append((char) val);
}
}
catch(IOException e){
Log.i("Error", e.getMessage());
}
JSONObject jsonObject = new JSONObject();
List<Location> listLocation = new ArrayList<Location>();
int countJson = 0;
try{
jsonObject = new JSONObject(builder.toString());
JSONArray jArray = jsonObject.getJSONArray("results");
countJson = jArray.length();
for(int i = 0; i < countJson; i++){
Location location = new Location();
String formattedAddress = ((JSONArray) jsonObject.get("results")).getJSONObject(i).getString("formatted_address");
double lat = ((JSONArray) jsonObject.get("results")).getJSONObject(i).getJSONObject("geometry").getJSONObject("location").getDouble("lat");
double lng = ((JSONArray) jsonObject.get("results")).getJSONObject(i).getJSONObject("geometry").getJSONObject("location").getDouble("lng");
location.setFormattedAddress(formattedAddress);
location.setLat(lat);
location.setLng(lng);
listLocation.add(location);
}
}
catch(JSONException e){
Log.i("Error", e.getMessage());
}
return listLocation;
}
else{
return null;
}
}
#Override
protected void onPreExecute(){
super.onPreExecute();
progress = new ProgressDialog(context);
progress.setMessage("Loading...");
progress.show();
}
#Override
protected void onPostExecute(List<Location> result){
super.onPostExecute();
progress.dismiss();
}
private boolean isNetworkAvailable(){
ConnectivityManager connManager = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo info = connManager.getActiveNetworkInfo();
return info != null && info.isConnected();
}
}
The ListView is on the same xml of the EditView and the Button.
Is there a way to improve it in order to make the UI not behave like this?
Thanks!

Try this:
btnSearch.setOnClickListener(new View.OnClickListener(){
#Override
public void onClick(View v){
String search = txtSearch.getText().toString();
new SearchTask(MainActivity.this).execute(strSearch);
}
}
#Override
protected void onPostExecute(List<Location> locations){
if(locations != null){
ArrayAdapter<Location> adapter = new ArrayAdapter<Location>(MainActivity.this, android.R.layout.simple_list_item_1, locations);
listView.setAdapter(adapter);
}
progress.dismiss();
}

Related

Android ListView duplicates data after pressing back button

I have a listview populated by the data from mysql database. It works fine but when I select an item then press back , the previous listview fecth again data from database that duplicates the items in my listview.
Here's is my code :
public class CityPage extends Activity{
Activity context;
HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
ProgressDialog pd;
CityAdapter cityAdapter;
ListView listCity;
ArrayList<City> records;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_city_page);
context = this;
records = new ArrayList<City>();
listCity = (ListView) findViewById(R.id.cities);
cityAdapter = new CityAdapter(context, R.layout.city_layout, R.id.city_name, records);
listCity.setAdapter(cityAdapter);
listCity.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent myIntent = new Intent(view.getContext(),City_attractions.class);
Toast.makeText(CityPage.this, "Opening", Toast.LENGTH_LONG).show();
String info1 = records.get(position).getCityName();
String info2 = records.get(position).getDescription();
myIntent.putExtra("info1", info1);
myIntent.putExtra("info2", info2);
startActivity(myIntent);
}
});
}
#Override
protected void onStart() {
super.onStart();
fetchCity fetch = new fetchCity();
fetch.execute();
}
private class fetchCity extends AsyncTask<Void, Void, Void> {
protected void onPreExecute() {
super.onPreExecute();
}
protected Void doInBackground(Void... params) {
InputStream is = null;
String result = "";
try {
httpclient = new DefaultHttpClient();
httppost = new HttpPost("http://iguideph-001-site1.btempurl.com/getcity.php");
response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
// Get our response as a String.
is = entity.getContent();
} catch (Exception e) {
if (pd != null)
pd.dismiss(); //close the dialog if error occurs
Log.e("ERROR", e.getMessage());
}
//convert response to string
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();
result = sb.toString();
} catch (Exception e) {
Log.e("ERROR", "Error converting result " + e.toString());
}
//parse json data
try {
// Remove unexpected characters that might be added to beginning of the string
result = result.substring(result.indexOf(""));
JSONArray jArray = new JSONArray(result);
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject(i);
City p = new City();
p.setCityName(json_data.getString("place_name"));
p.setDescription(json_data.getString("description"));
records.add(p);
}
} catch (Exception e) {
Log.e("ERROR", "Error pasting data " + e.toString());
}
return null;
}
protected void onPostExecute(Void result) {
if (pd != null) pd.dismiss(); //close dialog
Log.e("size", records.size() + "");
cityAdapter.notifyDataSetChanged(); //notify the ListView to get new records
}
}
}
try remove those lines from onstart() and put them inside oncreate() function
fetchCity fetch = new fetchCity();
fetch.execute();
Good luck !

Nothing happens in the try

In this activity, i get places nearby and add them to a listview. I wanted also to add the place's phone number in an arrayList like the other datas, so i had to use place details request. So, i get all the place_id for all the places from the arrayList and launch the query to get the details (phone number). The problem is in class "readFromGooglePlaceDetailsAPI", it goes in the "try" and goes out with nothing happening, i don't know why!!! I only can see "IN TRY !!!" and then "----" from the println.
Is my sequence not right?
Where is the problem and what is the solution ?
public class ListActivity extends Activity implements OnItemClickListener {
public ArrayList<GetterSetter> myArrayList;
ArrayList<GetterSetter> detailsArrayList;
ListView myList;
ProgressDialog dialog;
TextView nodata;
CustomAdapter adapter;
GetterSetter addValues;
GetterSetter addDetails;
private LocationManager locMan;
#Override protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.list_view_activity);
if (!isNetworkAvailable()) {
Toast.makeText(getApplicationContext(), "Enable internet connection and RE-LAUNCH!!",
Toast.LENGTH_LONG).show();
return;
}
myList = (ListView) findViewById(R.id.placesList);
placeSearch();
}
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null;
}
public void placeSearch() {
//get location manager
locMan = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
//get last location
Location lastLoc = locMan.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
double lat = lastLoc.getLatitude();
double lng = lastLoc.getLongitude();
dialog = ProgressDialog.show(this, "", "Please wait", true);
//build places query string
String placesSearchStr;
placesSearchStr = "https://maps.googleapis.com/maps/api/place/nearbysearch/" +
"json?location="+lat+","+lng+
"&radius=1000&sensor=true" +
"&types="+ ServicesListActivity.types+
"&key=My_KEY";
//execute query
new readFromGooglePlaceAPI().execute(placesSearchStr);
myList.setOnItemClickListener(this);
}
public void detailsSearch() {
String detailsSearchStr;
//build places query string
for(int i=0; i < myArrayList.size(); i++){
detailsSearchStr = "https://maps.googleapis.com/maps/api/place/details/json?" +
"placeid=" + myArrayList.get(i).getPlace_id() +
"&key=My_KEY";
Log.d("PlaceID:", myArrayList.get(i).getPlace_id());
//execute query
new readFromGooglePlaceDetailsAPI().execute(detailsSearchStr);
}
}
public class readFromGooglePlaceDetailsAPI extends AsyncTask<String, Void, String> {
#Override protected String doInBackground(String... param) {
return readJSON(param[0]);
}
protected void onPostExecute(String str) {
detailsArrayList = new ArrayList<GetterSetter>();
String phoneNumber =" -NA-";
try {
System.out.println("IN TRY !!!");
JSONObject root = new JSONObject(str);
JSONArray results = root.getJSONArray("result");
System.out.println("Before FOR !!!");
for (int i = 0; i < results.length(); i++) {
System.out.println("IN FOR LOOP !!!");
addDetails = new GetterSetter();
JSONObject arrayItems = results.getJSONObject(i);
if(!arrayItems.isNull("formatted_phone_number")){
phoneNumber = arrayItems.getString("formatted_phone_number");
Log.d("Phone Number ", phoneNumber);
}
addDetails.setPhoneNumber(phoneNumber);
System.out.println("ADDED !!!");
detailsArrayList.add(addDetails);
Log.d("Before", detailsArrayList.toString());
}
} catch (Exception e) {
}
System.out
.println("------------------------------------------------------------------");
Log.d("After:", detailsArrayList.toString());
// nodata = (TextView) findViewById(R.id.nodata);
//nodata.setVisibility(View.GONE);
// adapter = new CustomAdapter(ListActivity.this, R.layout.list_row, detailsArrayList);
// myList.setAdapter(adapter);
//adapter.notifyDataSetChanged();
// dialog.dismiss();
}
}
public class readFromGooglePlaceAPI extends AsyncTask<String, Void, String> {
#Override protected String doInBackground(String... param) {
return readJSON(param[0]);
}
protected void onPostExecute(String str) {
myArrayList = new ArrayList<GetterSetter>();
String rating=" -NA-";
try {
JSONObject root = new JSONObject(str);
JSONArray results = root.getJSONArray("results");
for (int i = 0; i < results.length(); i++) {
addValues = new GetterSetter();
JSONObject arrayItems = results.getJSONObject(i);
JSONObject geometry = arrayItems.getJSONObject("geometry");
JSONObject location = geometry.getJSONObject("location");
//place ID for place details later
String placeID = arrayItems.getString("place_id").toString();
if(!arrayItems.isNull("rating")){
rating = arrayItems.getString("rating");
}
addValues.setPlace_id(placeID);
addValues.setLat(location.getString("lat"));
addValues.setLon(location.getString("lng"));
addValues.setName(arrayItems.getString("name").toString());
addValues.setRating(rating);
addValues.setVicinity(arrayItems.getString("vicinity").toString());
myArrayList.add(addValues);
//Log.d("Before", myArrayList.toString());
}
} catch (Exception e) {
}
// System.out
// .println("############################################################################");
// Log.d("After:", myArrayList.toString());
nodata = (TextView) findViewById(R.id.nodata);
nodata.setVisibility(View.GONE);
adapter = new CustomAdapter(ListActivity.this, R.layout.list_row, myArrayList);
myList.setAdapter(adapter);
//adapter.notifyDataSetChanged();
dialog.dismiss();
detailsSearch();
}
}
public String readJSON(String URL) {
StringBuilder sb = new StringBuilder();
HttpGet httpGet = new HttpGet(URL);
HttpClient client = new DefaultHttpClient();
try {
HttpResponse response = client.execute(httpGet);
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == 200) {
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(content));
String line;
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} else {
Log.e("JSON", "Couldn't find JSON file");
}
} catch (ClientProtocolException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return sb.toString();
}
#Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
Intent details = new Intent(ListActivity.this, Details.class);
details.putExtra("name", myArrayList.get(arg2).getName());
details.putExtra("rating", myArrayList.get(arg2).getRating());
details.putExtra("vicinity", myArrayList.get(arg2).getVicinity());
details.putExtra("lat", myArrayList.get(arg2).getLat());
details.putExtra("lon", myArrayList.get(arg2).getLon());
details.putExtra("formatted_phone_number", detailsArrayList.get(arg2).getPhoneNumber());
startActivity(details);
}
}
try{
JSONObject jsonObject = new JSONObject(str);
if (jsonObject.has("results")) {
JSONArray jsonArray = jsonObject.getJSONArray("results");
for (int i = 0; i < jsonArray.length(); i++) {
//your logic here
}
}
} catch (JSONException e) {
e.printStackTrace();
}
Note that the getJSONArray() function throws an Exception if the mapping fails. For example I can't find a JSON Array which is called results.
The most important thing you have to do at first is:
change:
catch (Exception e) {
}
to
catch (Exception e) {
Log.e(YOUR_TAG, "Exception ..." , e);
}
Your try throws an Exception which you don't even Log. That might be the reason why you are confused.

Getting issue of Network Main Thread and Null Pointer exception

package com.Itattooz.Gallery;
#SuppressWarnings("unused")
public class grid_layout extends Activity {
private GridView list;
private String id_folder;
private LazyAdapter1 adapter;
private Intent intent;
private String main_folder;
private JSONArray jArray;
private String result = null;
private InputStream is = null;
private StringBuilder sb = null;
private String[] r;
boolean flag1 = false, flag2 = false, flag3 = false;
private String[] sub_folder_id;
private String[] path;
private String[] sub_folder_name;
private String[] flag;
private String previouse_folder;
private String[] url;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.grid_layout);
intent = getIntent();
main_folder = intent.getStringExtra("selected_item");
new Thread(new Runnable() {
public void run() {
databaseConnectivity();
}
}).start();
list = (GridView) findViewById(R.id.list);
adapter = new LazyAdapter1(this, url, sub_folder_name);
list.setAdapter(adapter);
list.setOnItemClickListener(grid_listener);
}
#Override
public void onDestroy() {
list.setAdapter(null);
super.onDestroy();
}
// djhwawd
OnItemClickListener grid_listener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position,
long id) {
id_folder = sub_folder_id[position];
flag1 = true;
TextView text = (TextView) v.findViewById(R.id.text);
String str = (String) text.getText();
if (flag[position].equals("X")) {
//main_folder = main_folder + "/" + str.replace(" ", "%20");
// int flags = Intent.FLAG_ACTIVITY_SINGLE_TOP;
intent = new Intent(v.getContext(), grid_layout_main.class);
intent.putExtra("folder_name", main_folder.replace(" ", "%20") + "/" + str.replace(" ", "%20"));
intent.putExtra("id", sub_folder_id[position]);
startActivity(intent);
} else {
flag2=true;
main_folder = main_folder + "/" + str.replace(" ", "%20");
int flags = Intent.FLAG_ACTIVITY_SINGLE_TOP;
intent = new Intent(v.getContext(), grid_layout.class);
intent.setFlags(flags);
intent.putExtra("selected_item", main_folder);
startActivity(intent);
}
}
};
#Override
protected void onNewIntent(Intent intent) {
setIntent(intent);
new Thread(new Runnable() {
public void run() {
databaseConnectivity();
}
}).start();
adapter = new LazyAdapter1(this, url, sub_folder_name);
list.setAdapter(adapter);
adapter.imageLoader.clearCache();
adapter.notifyDataSetChanged();
list.setOnItemClickListener(grid_listener);
}
public void databaseConnectivity() {
HttpPost httppost = null;
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
try {
HttpClient httpclient = new DefaultHttpClient();
if (flag1 == false) {
nameValuePairs
.add(new BasicNameValuePair("folder", main_folder));
httppost = new HttpPost(
"http://www.itattooz.com/android/index.php");
} else if (flag1 == true) {
nameValuePairs.add(new BasicNameValuePair("sub_folder_id",
id_folder));
httppost = new HttpPost(
"http://www.itattooz.com/android/index2.php");
}
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
} catch (Exception e) {
Log.e("log_tag", "Error in http connection" + e.toString());
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
} catch (Exception e) {
Log.e("log_tag", "Error converting result " + e.toString());
}
String rt;
try {
jArray = new JSONArray(result);
path = new String[jArray.length()];
sub_folder_id = new String[jArray.length()];
sub_folder_name = new String[jArray.length()];
flag = new String[jArray.length()];
url = new String[jArray.length()];
JSONObject json_data = null;
for (int i = 0; i < jArray.length(); i++) {
json_data = jArray.getJSONObject(i);
sub_folder_id[i] = json_data.getString("id");
sub_folder_name[i] = json_data.getString("folder");
flag[i] = json_data.getString("flag");
path[i] = json_data.getString("path");
rt = "http://www.itattooz.com/itattooz/"
+ main_folder.replace(" ", "%20") + "/"
+ sub_folder_name[i].replace(" ", "%20")
+ "/cover_image/" + path[i].replace(" ", "%20");
url[i] = rt;
}
} catch (JSONException e1) {
Toast.makeText(getBaseContext(), "No Image Found",
Toast.LENGTH_LONG).show();
} catch (ParseException e1) {
e1.printStackTrace();
}
}
#Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK)) {
onResume();
Log.d(this.getClass().getName(), "back button pressed");
}
return super.onKeyDown(keyCode, event);
}
#Override
public void onResume() { // After a pause OR at startup
super.onResume();
// Refresh your stuff here
}
#Override
protected void onPause() {
super.onPause();
}
}
Hello Above is my code for a Gallery view as a grid layout ..
I researched a lot on net and got to know I should use AsyncTask for what I am trying to achieve .. Here Are few problems i am facing
I am doing something on Main thread
I want to change it to AsyncTask..
Don't know what should I do exactly to get rid of this issue.. Please Help...
use the asyncTask to handle this exception.
Please see the android developer Link
or you can see the stackoverflow Accepted answer related to this Link HERE
For exmp
class YourTask extends AsyncTask<URL, Integer, String> {
protected String doInBackground(URL... urls) {
// Fetch Data (Task A)
return "Result";
}
protected void onProgressUpdate(Integer... progress) {
// Show progress
}
protected void onPostExecute(String result) {
// Show UI after complete (Task B)
}
}
Use Async Task
or
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
StrictMode.setThreadPolicy(policy);
}
use AsyncTask
or
add below code in your onCreate() method before thread starts to disable the strict mode using following code:
this is not the solution but avoids network IO on main thread so i recommend AsyncTask
if (android.os.Build.VERSION.SDK_INT > 9) {
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
}
also check internet permission in AndroidManifest.xml file
<uses-permission android:name="android.permission.INTERNET"/>

Android AsyncTask built wrongfully

In the application that I'm building, I have to load some datas from a database.
I load the datas when the user select an item from an alert dialog.
I use an AsyncTask class to connect to the database. Here's the code:
public class GetTask extends AsyncTask<Void,Void,Void>{
#Override
protected Void doInBackground(Void... arg0) {
getProdotti();
return null;
}
#Override
protected void onPostExecute(Void result) {
pg.dismiss();
for(int w=0;w<all_id.length;w++){
_id.add(all_id[w]);
nomi.add(all_names[w]);
foto.add(all_images[w]);
prezzi.add(all_prices[w]);
descr.add(all_desc[w]);
}
lista = (ListView)findViewById(R.id.lista_prodotti);
ListViewAdapter lva = new ListViewAdapter(nomi , foto , prezzi , _id , descr , context);
lista.setAdapter(lva);
}
protected void onPreExecute(Void result) {
pg = ProgressDialog.show(context, "", "Caricamento in corso...");
}
#Override
protected void onProgressUpdate(Void... values) {
}
}/**/
And i call it so
GetTask cat = new GetTask();
cat.execute();
The progress dialog is shown, but it doesn't disappear and the ListView is not populated.
What i'm doing wrong?
Here's getProdotti():
private void getProdotti(){
try{
httpclient = new DefaultHttpClient();
httppost = new HttpPost(host_url);
datas = new ArrayList<NameValuePair>(1);
datas.add(new BasicNameValuePair("categoria",selected));
Log.d("INVIO",selected);
httppost.setEntity(new UrlEncodedFormEntity(datas));
response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
inputStream = entity.getContent();
}catch (Exception e){
Toast.makeText(Catalogo.this, "error"+e.toString(), Toast.LENGTH_LONG).show();
}
if(inputStream != null){
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"),8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
inputStream.close();
result = sb.toString();
Log.d("RESULT",result);
}catch(Exception e){
Log.e("TEST", "Errore nel convertire il risultato "+e.toString());
}
try{
JSONArray jArray = new JSONArray(result);
all_id = new String[jArray.length()];
all_names = new String[jArray.length()];
all_prices = new String[jArray.length()];
all_images = new String[jArray.length()];
all_desc = new String[jArray.length()];
for(int i=0;i<jArray.length();i++){
JSONObject json_prod = jArray.getJSONObject(i);
Log.d("Debug",json_prod.getString("id_prodotto")+"--"+json_prod.getString("nome_prodotto"));
all_id[i]=json_prod.getString("id_prodotto");
all_names[i]=json_prod.getString("nome_prodotto");
all_prices[i]=json_prod.getString("prezzo");
all_images[i]=json_prod.getString("foto_prodotto");
all_desc[i]=json_prod.getString("descrizione");
}
}catch(JSONException e){
Log.e("log_tag", "Error parsing data "+e.toString());
}
}
}
Try adding lva.notifyDataSetChanged() inside onPostExecute like this :
lista = (ListView)findViewById(R.id.lista_prodotti);
ListViewAdapter lva = new ListViewAdapter(nomi , foto , prezzi , _id , descr , context);
lista.setAdapter(lva);
lva.notifyDataSetChanged();
Hope this helps, good luck ^^
Actually you have to tell the progress bar to disappear
you have tow ways
first
after setting the adapter to the list call
#Override
protected void onPostExecute(Void result) {
.....
pg.dismiss();
Or you can use handler
define a hanlder such
Handler handler = new Handler (){
#Override
protected void handleMessage(int what){
if(pg.isShowing()){
pg.dismiss();
}
}
}
And in onPostExecute method call
handler.sendEmptyMessage(0);
this will help !!!

How to make a TextView show a value from a AsynTask class

I have an AsynTask which retrieve data from a web service and with this data to be viewed on the UI. So, in my MainActivity, I have a textView.
This is the data I received from the webservice:
{"name":"ezio","country":"italy"}{"name":"fufu","country":"tutu"}{"name":"chikaka","country":"aceVentura"}
The problem is, I do not know how to set the textView with the value of 'result' from the ClientConnection class. When I run the application, the textView is empty.
public class ClientConnection extends AsyncTask {
public static final String URL = "http://192.168.0.15/test.php";
static JSONObject jObj = null;
public static String result = "";
#Override
protected String doInBackground(Void... voids) {
// public JSONObject connect(){
try{
HttpClient httpClient = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(URL);
HttpResponse response = httpClient.execute(httpGet);
int statusCode = response.getStatusLine().getStatusCode();
if (statusCode != HttpStatus.SC_OK) {
Log.e("HTTPStatus error:","Status not okay");
}
InputStream in = response.getEntity().getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(in, "iso-8859-1"), 8);
StringBuilder str = new StringBuilder();
String line = null;
while((line = reader.readLine()) != null){
str.append(line + "\n");
}
in.close();
result = str.toString();
JSONObject jsonObject = convertToJson(result);
// jsonObject.get()
//result = jsonObject.getString("name");
//JSONArray google = jsonObject.getJSONArray("");
} catch (Exception e) {
//Toast toast = Toast.makeText(null, e.getMessage(), Toast.LENGTH_LONG);
Log.e("Error","don't know what exception though");
}
return result;
}
private JSONObject convertToJson(String test){
JSONArray clients = new JSONArray();
try{
jObj = new JSONObject(test);
}catch (JSONException e){
Log.e("JSON Parser", "Error parsing data" + e.toString());
}
return jObj;
}
public String getResult(){
return result;
}
public JSONObject getjObj(){
return jObj;
}
}
And this is the Main Activity
public class MyActivity extends Activity {
/**
* Called when the activity is first created.
*/
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final TextView textView = (TextView) findViewById(R.id.textViewTest);
ListView listView = (ListView) findViewById(R.id.listView);
Button buttonConnect = (Button) findViewById(R.id.buttonConnect);
final ClientJSONParsingActivity clientJSONParsingActivity = new ClientJSONParsingActivity();
buttonConnect.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
new ClientConnection().execute();
textView.setText(new ClientConnection().getResult());
}
});
}
}
Thank you for your help
You can display the result in the onPostExecute in the AsyncTask.
You should update textview in your asynctask. onPostExecute() method runs on UI thread
protected void onPostExecute(String result) {
textView.setText(result);
}
Pass the text view as an argument to the asynctask and set it in onPostExecute. On my mobile so no code, sorry ;-)
add this code under your doinbackground;
protected void onPostExecute(Long result) {
(find your text view here from the context where textview it is)
textView.setText(result);
}

Categories

Resources