Android not parsing JSON data into ListView, I am using this tutorial and just made few changes in ListViewAdapter.java
Like in my new implementation i used ViewHolder, and my code looks like this:
public class ListViewAdapter extends BaseAdapter {
// Declare Variables
Context context;
ArrayList<HashMap<String, String>> data;
ImageLoader imageLoader;
HashMap<String, String> resultp = new HashMap<String, String>();
ViewHolder holder;
public ListViewAdapter(Context context,
ArrayList<HashMap<String, String>> arraylist) {
this.context = context;
data = arraylist;
imageLoader = new ImageLoader(context);
}
#Override
public int getCount() {
return data.size();
}
#Override
public Object getItem(int position) {
return data.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
static class ViewHolder {
public ViewHolder(View convertView) {
// TODO Auto-generated constructor stub
}
TextView rank;
TextView country;
TextView population;
ImageView flag;
}
public View getView(final int position, View convertView, ViewGroup parent) {
// Declare Variables
// Avoid unneccessary calls to findViewById() on each row, which is expensive!
holder = null;
/*
* If convertView is not null, we can reuse it directly, no inflation required!
* We only inflate a new View when the convertView is null.
*/
if (convertView == null) {
convertView = ((Activity) context).getLayoutInflater().inflate(R.layout.listview_item, null);
// Create a ViewHolder and store references to the two children views
holder = new ViewHolder(convertView);
holder.rank = (TextView) convertView.findViewById(R.id.rank);
holder.country = (TextView) convertView.findViewById(R.id.country);
holder.population = (TextView) convertView.findViewById(R.id.population);
// Locate the ImageView in listview_item.xml
holder.flag = (ImageView) convertView.findViewById(R.id.flag);
// The tag can be any Object, this just happens to be the ViewHolder
convertView.setTag(holder);
} else {
// Get the ViewHolder back to get fast access to the TextView
// and the ImageView.
holder = (ViewHolder) convertView.getTag();
}
// Capture position and set results to the TextViews
holder.rank.setText(resultp.get(MainActivity.RANK));
holder.country.setText(resultp.get(MainActivity.COUNTRY));
holder.population.setText(resultp.get(MainActivity.POPULATION));
// Capture position and set results to the ImageView
// Passes flag images URL into ImageLoader.class
imageLoader.DisplayImage(resultp.get(MainActivity.FLAG), holder.flag);
// Capture ListView item click
return convertView;
}
}
Edited: Click on ListItem code
#Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
listview = (ListView) findViewById(R.id.listview);
// Pass the results into ListViewAdapter.java
adapter = new ListViewAdapter(MainActivity.this, arraylist);
// Set the adapter to the ListView
listview.setAdapter(adapter);
// Close the progressdialog
mProgressDialog.dismiss();
listview.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// code to handle click
}
});
}
But i don't no why i am not getting data into ListView !
The issue is that you are not assigning the HashMap to `resultp that has the information you want to display
public View getView(final int position, View convertView, ViewGroup parent) {
holder = null;
if (convertView == null) {
convertView = ((Activity) context).getLayoutInflater().inflate(R.layout.listview_item, null);
holder = new ViewHolder(convertView);
holder.rank = (TextView) convertView.findViewById(R.id.rank);
holder.country = (TextView) convertView.findViewById(R.id.country);
holder.population = (TextView) convertView.findViewById(R.id.population);
holder.flag = (ImageView) convertView.findViewById(R.id.flag);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
// Here's the change
resultp = data.get(position);
// Here's the change
holder.rank.setText(resultp.get(MainActivity.RANK));
holder.country.setText(resultp.get(MainActivity.COUNTRY));
holder.population.setText(resultp.get(MainActivity.POPULATION));
imageLoader.DisplayImage(resultp.get(MainActivity.FLAG), holder.flag);
return convertView;
}
To attach OnItemClickListener to your ListView, in the Activity that contains the ListView, add the following:
public class MyActivity implements OnItemClickListener{
ListView lv;
#Override
public void onCreate(Bundle savedInstanceState() {
....
....
// lv initialized here
// adapter of lv set here
attachListeners();
}
private void attachListeners() {
....
....
// attach listeners to other views if you like
lv.setOnItemClickListener(this);
}
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// code to handle click
}
}
Or, if you don't want your Activity to implement OnItemClickListener, then,
public class MyActivity {
ListView lv;
#Override
public void onCreate(Bundle savedInstanceState() {
....
....
// lv initialized here
// adapter of lv set here
attachListeners();
}
private void attachListeners() {
....
....
// attach listeners to other views if you like
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
// code to handle click
}
});
}
}
First of all try to fix this:
#Override
public Object getItem(int position) {
return data.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
Related
I am trying to get the total of numbers in an sql table,
i first connected between android and sql but i can't
sum the numbers in the table column and show them
in a textview,like i want to get the total
of numbers in a column then
display them in a text view
,can someone help me with this task?
here is the code i used for
the listview
public class MyAppAdapter extends BaseAdapter //has a class viewholder which holds
{
public class ViewHolder
{
TextView textDate;
TextView textTotal;
TextView textLastTotal;
TextView textCount;
TextView textTaxs;
}
public List<ClassListItems2> parkingList;
public Context context;
ArrayList<ClassListItems2> arraylist;
private MyAppAdapter(List<ClassListItems2> apps, Context context)
{
this.parkingList = apps;
this.context = context;
arraylist = new ArrayList<ClassListItems2>();
arraylist.addAll(parkingList);
}
#Override
public int getCount() {
return parkingList.size();
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) // inflating the layout and initializing widgets
{
View rowView = convertView;
ViewHolder viewHolder= null;
if (rowView == null)
{
LayoutInflater inflater = getLayoutInflater();
rowView = inflater.inflate(R.layout.listcontent2, parent, false);
viewHolder = new ViewHolder();
viewHolder.textDate = (TextView) rowView.findViewById(R.id.date);
viewHolder.textLastTotal = (TextView) rowView.findViewById(R.id.lasttotal);
viewHolder.textTaxs = (TextView) rowView.findViewById(R.id.date3);
viewHolder.textCount = (TextView) rowView.findViewById(R.id.InvoicescCount);
viewHolder.textTotal = (TextView) rowView.findViewById(R.id.total);
rowView.setTag(viewHolder);
}
else
{
viewHolder = (ViewHolder) convertView.getTag();
}
// here setting up names and images
viewHolder.textDate.setText(parkingList.get(position).getDate()+"");
viewHolder.textTotal.setText(parkingList.get(position).getTotal());
viewHolder.textLastTotal.setText(parkingList.get(position).getLasttotal());
viewHolder.textTaxs.setText(parkingList.get(position).getTaxs());
viewHolder.textCount.setText(parkingList.get(position).getInvoicecount());
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//What happens when you click on a place!
}
});
return rowView;
}
This Adapter is feed with a Collection (List) in his constructor.
To know total numbers, in Activity/Fragment that handle that Collection use:
parkingList.size()
To get sum:
float total;
for (ClassListItems2 actualItem : parkingList) {
total += actualItem.getTotal()
}
All of this logic must be executed in Activity/Fragment, never in Adapter because the Adapter only got presentation/visual logic.
I'm new at android. and I want to load a new template which contains two button on a selected item of grid view object.
Is that possible.
I added a gridview to my project and by using base adapter a template was loaded to each item of gridview. But what I want is that when I clicked an item of gridview, I want to load a new template (layout) to the selected item.
THE PROBLEM WAS SOLVED, followings are the edited codes
Base Adapter
public class KategoriAdapter extends BaseAdapter{
private Context mContext;
private String[] categoryValues;
private Bitmap[] pictures;
//indicate that positon for new template
private int mNewTemplatePos = -1;
public KategoriAdapter(Context context, String[] categoryValues, Bitmap[] pictures) {
this.mContext = context;
this.categoryValues = categoryValues;
this.pictures = pictures;
}
//apply new template to positon
public void useNewTemplate(int pos) {
mNewTemplatePos =pos;
//notiy list that data has changed and the list will refresh ui itself.
notifyDataSetChanged();
}
#Override
public int getCount() {
return categoryValues.length;
}
#Override
public Object getItem(int possition) {
return null;
}
#Override
public long getItemId(int possition) {
return 0;
}
#Override
public View getView(int possition, View convertView, ViewGroup parent) {
final LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int posId = mNewTemplatePos;
if (convertView == null){
if (mNewTemplatePos ==possition){
convertView = getNewTemplate(inflater,possition);
}else {
convertView = getNormalTemplate(inflater,possition);
}
}else {
if (posId==possition){
convertView = getNewTemplate(inflater,possition);
}else{
convertView = getNormalTemplate(inflater,possition);
}
}
return convertView;
}
private View getNormalTemplate(LayoutInflater inflater, int possition) {
final View grid = inflater.inflate(R.layout.kategoriler_list_item, null);
TextView cName = (TextView) grid.findViewById(R.id.grid_item_ad);
ImageView categoryPictures = (ImageView) grid.findViewById(R.id.grid_item_resim);
cName.setText(categoryValues[possition]);
categoryPictures.setImageBitmap(pictures[possition]);
return grid;
}
private View getNewTemplate(LayoutInflater inflater, int possition) {
final View grid = inflater.inflate(R.layout.kategori_secenek_template, null);
TextView cName = (TextView) grid.findViewById(R.id.grid_item_ad);
cName.setText(categoryValues[possition]);
Button btn_nesne_tani = (Button) grid.findViewById(R.id.btn_nesneleri_taniyalim);
Button btn_cumle_kur = (Button) grid.findViewById(R.id.btn_cumle_kuralim);
btn_nesne_tani.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext,"nesne",Toast.LENGTH_SHORT).show();
}
});
btn_cumle_kur.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(mContext,"cümle",Toast.LENGTH_SHORT).show();
}
});
return grid;
}
}
KategoriActivity.java
.....
final KategoriAdapter adapter = new KategoriAdapter(getApplicationContext(), mKategoriler, kategoriResimleri);
grid=(GridView)findViewById(R.id.gv_kategoriler);
grid.setAdapter(adapter);
grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
adapter.useNewTemplate(position);
Toast.makeText(getApplicationContext(), mKategoriler[position].toString(),Toast.LENGTH_SHORT).show();
}
});
}
I have rewrite your KategoriAdapter class:
public class KategoriAdapter extends BaseAdapter {
private Context mContext;
private final String[] categoryValues;
private final Bitmap[] pictures;
//indicate that positon in list are all use new template
private List<Integer> mNewTemplatePos;
public ImageView categoryPictures;
//indicate that this is normal template view
private final String NORMAL_TEMPLATE = "NORMAL_TEMPLATE";
//indicate that this is new template view
private final String NEW_TEMPLATE = "NEW_TEMPLATE";
public KategoriAdapter(Context context, String[] categoryValues, Bitmap[] pictures) {
this.mContext = context;
this.categoryValues = categoryValues;
this.pictures = pictures;
this.mNewTemplatePos = new ArrayList<>();
}
//apply new template to positon
public void useNewTemplate(int pos) {
mNewTemplatePos.add(pos);
//notiy list that data has changed and the list will refresh ui itself.
notifyDataSetChanged();
}
#Override
public int getCount() {
return categoryValues.length;
}
#Override
public Object getItem(int possition) {
return null;
}
#Override
public long getItemId(int possition) {
return 0;
}
#Override
public View getView(int possition, View convertView, ViewGroup parent) {
final LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (convertView == null) {
if (mNewTemplatePos.contains(possition)) {
convertView = getNewTemplate(inflater, possition);
//use tag to indicate the type of the template
convertView.setTag(NEW_TEMPLATE);
} else {
convertView = getNormalTemplate(inflater, possition);
convertView.setTag(NORMAL_TEMPLATE);
}
} else {
switch ((String) convertView.getTag()) {
case NORMAL_TEMPLATE:
//convertView is the normal template view but you need a new template view in possition
if (mNewTemplatePos.contains(possition))
convertView = getNewTemplate(inflater, possition);
break;
case NEW_TEMPLATE:
//convertView is the new template view but you need a normal template view in possition
if (!mNewTemplatePos.contains(possition))
convertView = getNormalTemplate(inflater, possition);
break;
}
}
return convertView;
}
private View getNormalTemplate(LayoutInflater inflater, int possition) {
View grid = inflater.inflate(R.layout.kategoriler_list_item, null);
TextView cName = (TextView) grid.findViewById(R.id.grid_item_ad);
categoryPictures = (ImageView) grid.findViewById(R.id.grid_item_resim);
cName.setText(categoryValues[possition]);
categoryPictures.setImageBitmap(pictures[possition]);
return grid;
}
private View getNewTemplate(LayoutInflater inflater, int possition) {
// TODO: 31/08/16 inflate you new template view layout here
return youNewTemplateView;
}
}
You should determine wether if current contentView is the right template type in getView() because contentView may be one of the new template in your list when it is not null.It is convenient to use tag to indicate the template type.
When to use useNewTemplate(position)?
Just apply the position that you need to use new template to useNewTemplate（） and use it in your onItemClick() method.
grid.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
useNewTemplate(position);
}
});
I need help to fix the following problem:
When i scroll down my ListView Adapter the list that contains the country change to only one country.
This is my Adapter:
public class Nraeby_ListViewAdapter extends BaseAdapter {
private String Liked;
Context mContext;
// Declare Variables
LayoutInflater inflater;
private ArrayList<HashMap<String, String>> data;
ImageLoader imageLoader;
HashMap<String, String> resultp = new HashMap<String, String>();
public Nraeby_ListViewAdapter(Context context,
ArrayList<HashMap<String, String>> arraylist) {
this.data = arraylist;
mContext = context;
imageLoader = new ImageLoader(mContext);
inflater = LayoutInflater.from(mContext);
}
#Override
public int getCount() {
return data.size();
}
#Override
public Object getItem(int position) {
return data.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
public class ViewHolder {
// Declare Variables
TextView rank;
TextView country;
TextView population;
test.Droidlogin.CircleImage flag;
test.Droidlogin.material.AnimateCheckBox checkBox;
ImageButton btnFavourite;
}
public View getView(final int position, View view, ViewGroup parent) {
final ViewHolder holder;
if (view == null) {
holder = new ViewHolder();
view = inflater.inflate(R.layout.nearby_listview_item, null);
// Get the position
resultp = data.get(position);
// Locate the TextViews in nearby_listview_item.xmltem.xml
holder.rank = (TextView) view.findViewById(R.id.rank);
holder.country = (TextView) view.findViewById(R.id.country);
// Locate the ImageView in nearby_listview_item.xmltem.xml
holder.flag = (test.Droidlogin.CircleImage) view.findViewById(R.id.flag);
holder.checkBox = (test.Droidlogin.material.AnimateCheckBox) view.findViewById(R.id.checkbox);
holder.btnFavourite = (ImageButton) view.findViewById(R.id.like);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
// Capture position and set results to the TextViews
holder.rank.setText(resultp.get(NearbyUsers.RANK));
holder.country.setText(resultp.get(NearbyUsers.COUNTRY));
// Capture position and set results to the ImageView
// Passes flag images URL into ImageLoader.class
imageLoader.DisplayImage(resultp.get(NearbyUsers.FLAG), holder.flag);
TinyDB tinydb = new TinyDB(mContext);
Liked = tinydb.getString("MyUsers");
//This handle and change icon when click on.
holder.btnFavourite.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
TinyDB tinydb = new TinyDB(mContext);
holder.btnFavourite.setImageResource(R.drawable.icon_liked);
tinydb.putString("MyUsers",resultp.get(NearbyUsers.COUNTRY));
holder.btnFavourite.setImageResource(R.drawable.icon_liked);
}
});
// Capture ListView item click
view.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
// Get the position
Intent intent = new Intent(mContext, SingleItemViewNearbyProfile.class);
// Pass all data rank
intent.putExtra("rank", resultp.get(NearbyUsers.RANK));
// Pass all data country
intent.putExtra("country", resultp.get(NearbyUsers.COUNTRY));
// Pass all data population
intent.putExtra("population",resultp.get(NearbyUsers.POPULATION));
// Pass all data flag
intent.putExtra("flag", resultp.get(NearbyUsers.FLAG));
// Start SingleItemView Class
mContext.startActivity(intent);
}
});
return view;
}
}
pls i need help on how to fix the error
so that when scroll down it will show the list of all country and a button
You should move the line in getView to outside the if block. Like this
final ViewHolder holder;
resultp = data.get(position);
if (view == null) {
///
}
You are only updating the resultp when you create a new view. For a recycled view, you are using a stale data and that's the reason you see some incorrect country data after you scroll.
I have a created a ListView with a custom layout showing the users saved on Parse.com
This is the code for the custom adapter I have created
public class StatusAdapter extends ArrayAdapter {
protected Context mContext;
protected List mStatus;
public StatusAdapter(Context context, List status) {
super(context, R.layout.usertem, status);
mContext = context;
mStatus = status;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = LayoutInflater.from(mContext).inflate(
R.layout.usertem, null);
holder = new ViewHolder();
holder.usernameHomepage = (TextView) convertView
.findViewById(R.id.userName);
holder.statusHomepage = (TextView) convertView
.findViewById(R.id.userEmail);
holder.proPic = (ParseImageView) convertView
.findViewById(R.id.medopic);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
ParseUser statusObject = (ParseUser) mStatus.get(position);
// title
String username = statusObject.getString("name");
holder.usernameHomepage.setText(username);
// content
String status = statusObject.getEmail();
holder.statusHomepage.setText(status);
ParseFile picc = statusObject.getParseFile("profile_picture");
holder.proPic.setParseFile(picc);
holder.proPic.loadInBackground();
return convertView;
}
public static class ViewHolder {
TextView usernameHomepage;
TextView statusHomepage;
ParseImageView proPic;
}
}
But the problem I have is that I want to listen to list item clicks where my activity extends simple activity not List Activity this is my activity
public class UsersList extends Activity {
private ParseQueryAdapter<ParseObject> mainAdapter;
protected List<ParseUser> mUsers;
ListView listhope;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_users_list);
listhope = (ListView) findViewById(R.id.userlistlist);
ParseQuery<ParseUser> query = new ParseQuery<ParseUser>("_User");
query.findInBackground(new FindCallback<ParseUser>() {
#Override
public void done(List<ParseUser> list, ParseException e) {
if (e == null) {
mUsers = list;
StatusAdapter adapter = new StatusAdapter(listhope.getContext(), mUsers);
listhope.setAdapter(adapter);
} else {
}
}
});
}
[...]
Please help fast
In your onCreate write
listhope.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//position is the row on which the user has clicked
ParseUser parseUser=mUsers.get(position);
//now you have the objext parseUser and this objects is what you needed.
}
});
I used fragment in my app and i'm using SQLite to save local data. But when I finished saving data, and I swipe the page, my listView is not refreshed with new data (Only showing old data). I have tried to provide a method notifyDataSetChanged() on my adapter, but it's not working.
My Base Adapter class :
public class LocalDataAdapter extends BaseAdapter {
private Activity activity;
private ArrayList<LocalDataBean> data;
private static LayoutInflater inflater = null;
public LocalDataAdapter(Activity a, ArrayList<LocalDataBean> d) {
activity = a;
data = d;
inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return data.size();
}
#Override
public Object getItem(int position) {
return data.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
public void setItem(ArrayList<LocalDataBean> data){
this.data = data;
notifyDataSetChanged();
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = inflater.inflate(R.layout.list_item, null);
TextView nama_konsumen = (TextView) v.findViewById(R.id.nama_konsumen);
TextView no_telp = (TextView) v.findViewById(R.id.no_telp);
TextView no_hp_cdma = (TextView) v.findViewById(R.id.no_hp_cdma);
TextView no_hp_gsm = (TextView) v.findViewById(R.id.no_hp_gsm);
LocalDataBean obj = (LocalDataBean) getItem(position);
nama_konsumen.setText(obj.getNamaKonsumen());
no_telp.setText(obj.getNoTelp());
no_hp_cdma.setText(obj.getNoCMDA());
no_hp_gsm.setText(obj.getNoGSM());
return v;
}
}
My fragment class :
public class LocalDataFragment extends Fragment {
View view;
Activity act;
SQLHandlerBean utilSql;
ArrayList<LocalDataBean> localdatabean = new ArrayList<LocalDataBean>();
LocalDataAdapter adapter;
ListView list;
public static final String TAG = LocalDataFragment.class.getSimpleName();
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
view = inflater.inflate(R.layout.layout_local_data, null);
act = getActivity();
list = (ListView) view.findViewById(R.id.listViewLocalData);
utilSql = new SQLHandlerBean(this.act);
adapter = new LocalDataAdapter(act, localdatabean);
localdatabean = new ArrayList<LocalDataBean>();
list.setAdapter(adapter);
if (utilSql.ReadAllLocalData().size() < 1) {
Toast.makeText(act, "DATA EMPTY!", Toast.LENGTH_LONG).show();
} else {
localdatabean = utilSql.ReadAllLocalData();
Log.e(TAG, "TOTAL DATA : "+localdatabean.size());
adapter.setItem(localdatabean);
adapter.notifyDataSetChanged();
}
return view;
}
}
Is adapter.notifyDataSetChanged() placement correct?
No, the placement is not in the right place.
As you have placed the notifyDataSetChanged() inside of the onCreateView() method. It will be only invoked 1st time the fragment is launched.
Rather you can add a refresh button in your layout (or in you action bar). And along with the insertion/deletion method of the data, place the notifyDataSetChanged() at the bottom of the click event of that button.
By doing this user can refresh the page whenever they want.
And if you want to refresh the page by swipping the view then, SwipeRefreshLaoyout could be a perfect alternative.
You can check this blog.