Android notifyDataSetChanged not working - android

I have an adapter which fills a ListView with 2 TextViews with data from a TreeMap.
When the user adds or deletes Data from the ListView, the View should be refreshed.
So here is my Adapter:
public class MyAdapter extends BaseAdapter {
private final ArrayList mData;
public MyAdapter(Map<String, String> map) {
mData = new ArrayList();
mData.addAll(map.entrySet());
}
#Override
public int getCount() {
return mData.size();
}
#Override
public Map.Entry<String, String> getItem(int position) {
return (Map.Entry) mData.get(position);
}
#Override
public long getItemId(int position) {
// TODO implement you own logic with ID
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
final View result;
if (convertView == null) {
result = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_adapter_item, parent, false);
} else {
result = convertView;
}
Map.Entry<String, String> item = getItem(position);
// TODO replace findViewById by ViewHolder
((TextView) result.findViewById(android.R.id.text1)).setText(item.getKey());
((TextView) result.findViewById(android.R.id.text2)).setText(item.getValue());
return result;
}}
Because I want to update the view from a dialog and on another question I read, that notifyDataSetChanged() needs to be called from the UIThread I put my notifyDataSetChanged() into a Runnable. here is it:
Runnable run = new Runnable(){
public void run(){
Log.v("in the Runnable: ", String.valueOf(colorHashMap));
adapter.notifyDataSetChanged();
}
};
And this it how the Runnable gets called in the Dialog:
DefaultColorActivity.this.runOnUiThread(run);
But I no matter what I try or do, the List just won't get updated. I need to close and reopen the activity to get the new List.

create a method in your adapter like:
public void updateList(){
notifyDataSetChanged()
}
and call this method when you want to refresh the list

Call notifyDataSetChanged() method from your Adapter class (in getView() method) which extends BaseAdapter after deleting item.

First of all you have to make changes in map (Data source of the adapter). And use Handler class(Android OS Thread) to run the thread like this
Handler handler=new Handler();
handler.post(run);

you can not create object of list.
just create reference and asign list to your list
remove this statement in you adapter class
mData = new ArrayList();

Related

Load more option in list view did not show previous list in android

i have parsed Json data from the server. On which im showing all the data in listview and i have Load more option below the ListView. Now when i click load more option, this application reload whole list and did not show previous list data. Please help me find out the solution. Here is footer view click listener :
lFooter.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
page += 1;
new ParseIssues().execute();
listView.removeFooterView(v);
}
});
in above code ParseIssues class parse json values and displays all the data in ListView Here is code for onPostExecute of AsynkTask class :
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if(page < totalPage){
listView.addFooterView(v);
}
listAdapter = new ListAdapterForSearch(activity, mainList);
listView.setAdapter(listAdapter);
// get listview current position - used to maintain scroll position
int currentPosition = listView.getFirstVisiblePosition();
listView.setSelection(currentPosition);
}
Here is BaseAdapter class:
public class ListAdapterForSearch extends BaseAdapter {
private Activity activity;
private ArrayList<HashMap<String, String>> data;
private static LayoutInflater inflater = null;
public ListAdapterForSearch(Activity a, ArrayList<HashMap<String, String>> d) {
activity = a;
data = d;
inflater = LayoutInflater.from(activity);
}
#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;
}
#Override
public View getView(final int position, View convertView, final ViewGroup parent) {
View vi = convertView;
if (convertView == null) {
vi = inflater.inflate(R.layout.list_row_item, null);
}
TextView title = (TextView)vi.findViewById(R.id.title);
HashMap<String, String> hash = new HashMap<String, String>();
hash = data.get(position);
title.setText(hash.get("title"));
return vi;
}
}
The answer to your question lies with the variable "mainList", which the adapter uses. You need to add the new data to it, basically this list needs to contain all the data you want to show in your ListView.
You should set adapter on create, after that first add loaded data to mainlist(add new loaded data) & then after loading notify adapter like listadapter.notifydatachange()
Edit: Because every time you are creating adapter that's why you are facing this problem, instead after loading just notify your adapter..
Check in your code you may have clear your mainList.

How to detect change in listview from mainactivity

Summary: I need a way to trigger my calculate() function within my main activity when an item is added or removed from my ListView
Background:
My android application fills a listview with list items. A list item contains a textview and an imagebutton (delete) that removes the item from the list on click. I use a custom adapter to keep track of changes in the list. This all works fine.
In my main acticity, some calculations take place based on the values in the list in a function called calulate(). I want to call this function whenever an item is added or deleted from the list. However, I don't know if this is possible and how to implement such a function.
I noticed that it is possible to add an observer using registerDataSetObserver() that will be notified when notifyDataSetChanged() is called. However, I'm not sure if this is what I need and how to implement this. Any help or suggestions are more than welcome.
Here is my CustomListAdapter:
public class CustomListAdapter extends BaseAdapter {
static final String TAG = "CustomListAdapter";
private Context context;
ArrayList <String> listArray;
LayoutInflater inflater;
public CustomListAdapter(Context context, List <String> inputArray) {
super();
this.context = context;
this.listArray = (ArrayList<String>) inputArray;
}
#Override
public int getCount() {
return listArray.size(); // total number of elements in the list
}
#Override
public String getItem(int i) {
return listArray.get(i); // single item in the list
}
#Override
public long getItemId(int i) {
return i; // index number
}
#Override
public View getView(int position, View convertView, final ViewGroup parent) {
View V = convertView;
if(V == null) {
LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
V = vi.inflate(R.layout.selected_drug_list_item, null);
}
//place text in textview
String listItem = listArray.get(position);
TextView textView = (TextView) V.findViewById(R.id.selectedDrugName);
textView.setText(listItem);
ImageButton deleteSelectedDrugButton = (ImageButton) V.findViewById(R.id.deleteSelectedDrugButton);
deleteSelectedDrugButton.setTag(position);
//Listener for the delete button. Deletes item from list.
deleteSelectedDrugButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
//re
Integer index = (Integer) view.getTag();
listArray.remove(index.intValue());
notifyDataSetChanged();
}
});
return V;
}
public void add(String input) {
listArray.add(input);
notifyDataSetChanged();
Log.v(TAG, input + " added to list");
}
public void remove(String input){
listArray.remove(input);
notifyDataSetChanged();
Log.v(TAG, input + " added to list");
}
}
Here is how my ListView is initialized in my onCreate() method.
selectionListView = (ListView) findViewById(R.id.selectionListView);
selectionAdapter = new CustomListAdapter(this,myListItems);
selectionListView.setAdapter(selectionAdapter);
If any other code fragment is required, I'll happily provide it.
You may create Interfece that will be implemented by Your Main Activity and passed to Adapter (eg. in constructor)
public interface SomeInterface
{
public void foo();
}
Add SomeInterface object in Your Adapter
SomeInterface responder=null;
public CustomListAdapter(Context context, List <String> inputArray, SomeInterface responder) {
super();
this.context = context;
this.listArray = (ArrayList<String>) inputArray;
this.responder=responder;
}
public void add(String input) {
listArray.add(input);
notifyDataSetChanged();
Log.v(TAG, input + " added to list");
responder.foo();
}
public void remove(String input){
listArray.remove(input);
notifyDataSetChanged();
Log.v(TAG, input + " added to list");
responder.foo();
}
and implements SomeInterface in Your MainActivity
public class MainActivity extends Activity implements SomeInterface
{
...
public void foo()
{
//do whatever
}
private initializeAdapter()
{
CustomListAdapter adapter=new Adapter(this, someArray, this);
}
}
You can create a callback interface with a simple method, like stuffHappened(). Then, let your activity implement that interface. Now you can add a constructor argument which has as type the callback interface, pass the activity in, keep it as a member variable on the adapter and call the stuffHappened() method whenever you need to send feedback to your activity.

notifyDataSetChange not working from custom adapter

When I repopulate my ListView, I call a specific method from my Adapter.
Problem:
When I call updateReceiptsList from my Adapter, the data is refreshed, but my ListView doesn't reflect the change.
Question:
Why doesn't my ListView show the new data when I call notifyDataSetChanged?
Adapter:
public class ReceiptListAdapter extends BaseAdapter {
public List<Receipt> receiptlist;
private Context context;
private LayoutInflater inflater;
private DateHelpers dateH;
public ReceiptListAdapter(Activity activity, Context mcontext, List<Receipt> rl) {
context = mcontext;
receiptlist = rl;
Collections.reverse(receiptlist);
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
dateH = new DateHelpers();
}
#Override
public int getCount() {
try {
int size = receiptlist.size();
return size;
} catch(NullPointerException ex) {
return 0;
}
}
public void updateReceiptsList(List<Receipt> newlist) {
receiptlist = newlist;
this.notifyDataSetChanged();
}
#Override
public Receipt getItem(int i) {
return receiptlist.get(i);
}
#Override
public long getItemId(int i) {
return receiptlist.get(i).getReceiptId() ;
}
private String getPuntenString(Receipt r) {
if(r.getPoints().equals("1")) {
return "1 punt";
}
return r.getPoints()+" punten";
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
final Receipt receipt = receiptlist.get(position);
ReceiptViewHolder receiptviewholder;
Typeface tf_hn = Typeface.createFromAsset(context.getAssets(), "helveticaneue.ttf");
Typeface tf_hn_bold = Typeface.createFromAsset(context.getAssets(), "helveticaneuebd.ttf");
if (vi == null) { //convertview==null
receiptviewholder = new ReceiptViewHolder();
vi = inflater.inflate(R.layout.view_listitem_receipt, null);
vi.setOnClickListener(null);
vi.setOnLongClickListener(null);
vi.setLongClickable(false);
receiptviewholder.shop = (TextView) vi.findViewById(R.id.tv_listitemreceipt_shop);
receiptviewholder.date = (TextView) vi.findViewById(R.id.tv_listitemreceipt_date);
receiptviewholder.price = (TextView) vi.findViewById(R.id.tv_listitemreceipt_price);
receiptviewholder.points = (TextView) vi.findViewById(R.id.tv_listitemreceipt_points);
receiptviewholder.shop.setTypeface(tf_hn_bold);
receiptviewholder.price.setTypeface(tf_hn_bold);
vi.setTag(receiptviewholder);
}else{//convertview is not null
receiptviewholder = (ReceiptViewHolder)vi.getTag();
}
receiptviewholder.shop.setText(receipt.getShop());
receiptviewholder.date.setText(dateH.timestampToDateString(Long.parseLong(receipt.getPurchaseDate())));
receiptviewholder.price.setText("€ "+receipt.getPrice());
receiptviewholder.points.setText(getPuntenString(receipt));
vi.setClickable(false);
return vi;
}
public static class ReceiptViewHolder {
public TextView shop;
public TextView date;
public TextView price;
public TextView points;
}
public Object getFilter() {
// XXX Auto-generated method stub
return null;
}
}
--EDIT:
found Workaround
Just to have some functional code i do now:
listview.setAdapter( new ReceiptListAdapter(activity,mcontext, -new dataset-);
Works, but not how it is supposed to work.
Change your method from
public void updateReceiptsList(List<Receipt> newlist) {
receiptlist = newlist;
this.notifyDataSetChanged();
}
To
public void updateReceiptsList(List<Receipt> newlist) {
receiptlist.clear();
receiptlist.addAll(newlist);
this.notifyDataSetChanged();
}
So you keep the same object as your DataSet in your Adapter.
I have the same problem, and i realize that. When we create adapter and set it to listview, listview will point to object somewhere in memory which adapter hold, data in this object will show in listview.
adapter = new CustomAdapter(data);
listview.setadapter(adapter);
if we create an object for adapter with another data again and notifydatasetchanged():
adapter = new CustomAdapter(anotherdata);
adapter.notifyDataSetChanged();
this will do not affect to data in listview because the list is pointing to different object, this object does not know anything about new object in adapter, and notifyDataSetChanged() affect nothing.
So we should change data in object and avoid to create a new object again for adapter
As I have already explained the reasons behind this issue and also how to handle it in a different answer thread Here. Still i am sharing the solution summary here.
One of the main reasons notifyDataSetChanged() won't work for you - is,
Your adapter loses reference to your list.
When creating and adding a new list to the Adapter. Always follow these guidelines:
Initialise the arrayList while declaring it globally.
Add the List to the adapter directly with out checking for null and empty
values . Set the adapter to the list directly (don't check for any
condition). Adapter guarantees you that wherever you make
changes to the data of the arrayList it will take care of it, but never loose the
reference.
Always modify the data in the arrayList itself (if your data is completely new
than you can call adapter.clear() and arrayList.clear() before
actually adding data to the list) but don't set the adapter i.e If
the new data is populated in the arrayList than just
adapter.notifyDataSetChanged()
Hope this helps.
Maybe try to refresh your ListView:
receiptsListView.invalidate().
EDIT: Another thought came into my mind. Just for the record, try to disable list view cache:
<ListView
...
android:scrollingCache="false"
android:cacheColorHint="#android:color/transparent"
... />
I had the same problem using ListAdapter
I let Android Studio implement methods for me and this is what I got:
public class CustomAdapter implements ListAdapter {
...
#Override
public void registerDataSetObserver(DataSetObserver observer) {
}
#Override
public void unregisterDataSetObserver(DataSetObserver observer) {
}
...
}
The problem is that these methods do not call super implementations so notifyDataSetChange is never called.
Either remove these overrides manually or add super calls and it should work again.
#Override
public void registerDataSetObserver(DataSetObserver observer) {
super.registerDataSetObserver(observer);
}
#Override
public void unregisterDataSetObserver(DataSetObserver observer) {
super.unregisterDataSetObserver(observer);
}
If adapter is set to AutoCompleteTextView then notifyDataSetChanged() doesn't work.
Need this to update adapter:
myAutoCompleteAdapter = new ArrayAdapter<String>(MainActivity.this,
android.R.layout.simple_dropdown_item_1line, myList);
myAutoComplete.setAdapter(myAutoCompleteAdapter);
Refer: http://android-er.blogspot.in/2012/10/autocompletetextview-with-dynamic.html
class StudentAdapter extends BaseAdapter {
ArrayList<LichHocDTO> studentList;
private void capNhatDuLieu(ArrayList<LichHocDTO> list){
this.studentList.clear();
this.studentList.addAll(list);
this.notifyDataSetChanged();
}
}
You can try. It work for me
If by any chance you landed on this thread and wondering why adapter.invaidate() or adapter.clear() methods are not present in your case then maybe because you might be using RecyclerView.Adapter instead of BaseAdapter which is used by the asker of this question. If clearing the list or arraylist not resolving your problem then it may happen that you are making two or more instances of the adapter for ex.:
MainActivity
...
adapter = new CustomAdapter(list);
adapter.notifyDataSetChanged();
recyclerView.setAdapter(adapter);
...
and
SomeFragment
...
adapter = new CustomAdapter(newList);
adapter.notifyDataSetChanged();
...
If in the second case you are expecting a change in the list of inflated views in recycler view then it is not gonna happen as in the second time a new instance of the adapter is created which is not attached to the recycler view. Setting notifyDataSetChanged in the second adapter is not gonna change the content of recycer view. For that make a new instance of the recycler view in SomeFragment and attach it to the new instance of the adapter.
SomeFragment
...
recyclerView = new RecyclerView();
adapter = new CustomAdapter();
recyclerView.setAdapter(adapter);
...
Although, I don't recommend making multiple instances of the same adapter and recycler view.
In my case I simply forget to add in my fragment mRecyclerView.setAdapter(adapter)
Add this code
runOnUiThread(new Runnable() { public void run() {
adapter = new CustomAdapter(anotherdata);
adapter.notifyDataSetChanged();
}
});
I made a very noob mistake that I was setting the adapter of RecyclerView before initialzing the adapter itself like this.
// Assuume oneOffJobTasksListRVAdapter is declared already
recyclerView.setAdapter(oneOffJobTasksListRVAdapter);
oneOffJobTasksListRVAdapter = new OneOffJobTasksListRVAdapter();
Switching the lines fixed my issue.
oneOffJobTasksListRVAdapter = new OneOffJobTasksListRVAdapter();
recyclerView.setAdapter(oneOffJobTasksListRVAdapter);
If you're using a custom adapter you have to add
#Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
to your custom adapter methods, then you only need to call notifyDataSetChanged() after you change your data, like replace, remove or add a new item
ArrayList <String> items;
int position=1;
items.set(position,"Changed Item");
items.remove(position);
items.add("New item");
notifyDataSetChanged();
I have the same problem
but I just finished it!!
you should change to
public class ReceiptListAdapter extends BaseAdapter {
public List<Receipt> receiptlist;
private Context context;
private LayoutInflater inflater;
private DateHelpers dateH;
private List<ReceiptViewHolder> receiptviewlist;
public ReceiptListAdapter(Activity activity, Context mcontext, List<Receipt> rl) {
context = mcontext;
receiptlist = rl;
receiptviewlist = new ArrayList<>();
receiptviewlist.clear();
for(int i = 0; i < receiptlist.size(); i++){
ReceiptViewHolder receiptviewholder = new ReceiptViewHolder();
receiptviewlist.add(receiptviewholder);
}
Collections.reverse(receiptlist);
inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
dateH = new DateHelpers();
}
#Override
public int getCount() {
try {
int size = receiptlist.size();
return size;
} catch(NullPointerException ex) {
return 0;
}
}
public void updateReceiptsList(List<Receipt> newlist) {
receiptlist = newlist;
this.notifyDataSetChanged();
}
#Override
public Receipt getItem(int i) {
return receiptlist.get(i);
}
#Override
public long getItemId(int i) {
return receiptlist.get(i).getReceiptId() ;
}
private String getPuntenString(Receipt r) {
if(r.getPoints().equals("1")) {
return "1 punt";
}
return r.getPoints()+" punten";
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View vi=convertView;
final Receipt receipt = receiptlist.get(position);
ReceiptViewHolder receiptviewholder;
Typeface tf_hn = Typeface.createFromAsset(context.getAssets(), "helveticaneue.ttf");
Typeface tf_hn_bold = Typeface.createFromAsset(context.getAssets(), "helveticaneuebd.ttf");
if (vi == null) { //convertview==null
ReceiptViewHolder receiptviewholder = receiptviewlist.get(position);
vi = inflater.inflate(R.layout.view_listitem_receipt, null);
vi.setOnClickListener(null);
vi.setOnLongClickListener(null);
vi.setLongClickable(false);
receiptviewholder.shop = (TextView) vi.findViewById(R.id.tv_listitemreceipt_shop);
receiptviewholder.date = (TextView) vi.findViewById(R.id.tv_listitemreceipt_date);
receiptviewholder.price = (TextView) vi.findViewById(R.id.tv_listitemreceipt_price);
receiptviewholder.points = (TextView) vi.findViewById(R.id.tv_listitemreceipt_points);
receiptviewholder.shop.setTypeface(tf_hn_bold);
receiptviewholder.price.setTypeface(tf_hn_bold);
vi.setTag(receiptviewholder);
}else{//convertview is not null
receiptviewholder = (ReceiptViewHolder)vi.getTag();
}
receiptviewholder.shop.setText(receipt.getShop());
receiptviewholder.date.setText(dateH.timestampToDateString(Long.parseLong(receipt.getPurchaseDate())));
receiptviewholder.price.setText("€ "+receipt.getPrice());
receiptviewholder.points.setText(getPuntenString(receipt));
vi.setClickable(false);
return vi;
}
public static class ReceiptViewHolder {
public TextView shop;
public TextView date;
public TextView price;
public TextView points;
}
public Object getFilter() {
// XXX Auto-generated method stub
return null;
}
}
My case was different but it might be the same case for others
for those who still couldn't find a solution and tried everything above, if you're using the adapter inside fragment then the reason it's not working fragment could be recreating so the adapter is recreating everytime the fragment recreate
you should verify if the adapter and objects list are null before initializing
if(adapter == null){
adapter = new CustomListAdapter(...);
}
...
if(objects == null){
objects = new ArrayList<>();
}

How to delete a custom listview item in android?

I have a listview and a button in my layout file. I'am adding items to listview on click of that button. The listview should be empty when the activity is started but it should grow by adding the items to it.
This is my code inside onCreate() :
list = (ListView)findViewById(R.id.inverterListView);
adapter = new ArrayAdapter<String>(InverterList.this, R.layout.inverters_list_row, R.id.inverterNumberTextViewInPanelListRow);
list.setAdapter(adapter);
And here iam adding the items to listview onclick of a button.
adapter.add(inverterNo);
adapter.notifyDataSetChanged();
This works fine. Can anyone guide me to delete custom listview item ? Thanks in advance.
If you know the position of the item you can do this:
Object item = adapter.getItem(position);
adapter.remove(item);
adapter.notifyDataSetChanged();
You may write your own adapter extends BaseAdapter and implement all you need methods.
It is example of my adapter:
public class PeopleUserAdapter extends BaseAdapter
{
private List<User> users;
private int viewResourceId;
private Context context;
public PeopleUserAdapter(Context context, int viewResourceId)
{
this.context = context;
this.viewResourceId = viewResourceId;
this.users = new ArrayList<User>();
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
UserItemHolder holder;
if (convertView == null)
{
convertView = LayoutInflater.from(context).inflate(viewResourceId, parent, false);
holder = new UserItemHolder(convertView);
}
else holder = (UserItemHolder) convertView.getTag();
User user = getItem(position);
holder.name.setText("#" + user.getLogin());
return convertView;
}
#Override
public int getCount()
{
return users.size();
}
#Override
public User getItem(int position)
{
return users.get(position);
}
#Override
public long getItemId(int position)
{
return getItem(position).hashCode();
}
public void clear()
{
users.clear();
}
public void addAll(Collection<User> users)
{
this.users.addAll(users);
notifyDataSetChanged();
}
public void replace(Collection<User> users)
{
clear();
addAll(users);
}
public static PeopleUserAdapter init(Context context)
{
return new PeopleUserAdapter(context, R.layout.item_user);
}
}
adapter.remove(item) .. and then call adapter.notifyDataSetChanged();
In case you are using a custom adapter (for a custom layout listview), you will want to do this:
When your Adapter is something like:
public class YourAdapterName extends ArrayAdapter<yourObject>
then the code for deleting the selected ListView Item will be:
ListView yourListView = (ListView) findViewById(R.id.listviewid);
YourAdapterName adapter;
adapter = (YourAdapterName) yourListView.getAdapter();
yourObject theitem = adapter.getItem(position);
adapter.remove(theitem);
adapte.notifyDataSetChanged();
This is assuming you are inside an event that gives you access to the current position inside the listview. like:
public boolean onItemLongClick(AdapterView<?> parent, View strings,int position, long id)
or
public void onItemClick(AdapterView<?> arg0, View v, int position, long id)
Otherwise you will need to obtain that position some other way, like storing it (onItemClick or onItemLongClick) in a textView with Visibility.GONE, and retrieve it when clicking the button (this is silly, you can use all kinds of storage options, like global variables, database and such).
Make sure you have overridden the remove method on your custom adapter
For example if this is your add method:
#Override
public void add(String[] object) {
scoreList.add(object);
super.add(object);
}
then your remove method would look something like this:
#Override
public void remove(String[] object) {
scoreList.remove(object);
super.remove(object);
}
call the below two lines::
adapter.remove(inverterNo);
adapter.notifyDataSetChanged();
where inverterNo is your item
It easy; you only to need is: add a method public in your personalize adapter some this:
public void remove(int position) {
itemsMovieModelFiltered.remove(position);
notifyDataSetChanged();
}
Remenber, this method you must add in your personalize adapter.
Then, call this method from other
adapte=new PersonalizeListAdapter(getActivity().getApplicationContext(),
movieModelList);
adapte.remove(position);

Android listview item doesn't appear

I should write in the title instead of 'doesn't work' something like 'I
don't know how to do it' but the first version feels better :).
What I am trying to do is the following:
Download the xml from the web, parse it and create ArrayList of some
objects (done and working)
Display the objects using custom Adapter (doesn't work)
The second one works if I add the items to my ArrayList before I add it to
the view using
m_orderAdapter = new OrderAdapter(this,m_orders); //code for orderadapter
below
setListAdapter(m_orderAdapter);
I have found on the web something like this: (in my onCreate method)
handler = new Handler();
viewOrders = new Runnable(){
#Override
public void run() {
getOrders();
}
};
new Thread(){
#Override
public void run(){
handler.post(viewOrders);
}
}.start();
then, the following code for the methods:
private void getOrders(){
try{
OrderManager om = new OrderManager();
m_orders = om.getOrdersFromWeb();
Log.i("ARRAY", ""+ m_orders.size());
} catch (Exception e) {
Log.e("BACKGROUND_PROC", e.getMessage());
}
runOnUiThread(returnRes);
}
OrderManager downloads and parse the xml into Order objects and returns
array list of those. Then I set this list to my member array list m_orders.
Once downloading and parsing is done I run returnRes method on the ui thread
using runOnUiThread method
private Runnable returnRes = new Runnable() {
#Override
public void run() {
if(m_orders != null && m_orders.size() > 0){
Log.i("ORDER",m_orders.get(0).getOrder_id());
setListAdapter(m_orderAdapter);
m_orderAdapter.notifyDataSetChanged();
}
m_orderAdapter.notifyDataSetChanged();
}
};
and I call notifyDataSetChanged() on my adapter.
The view I do all this stuff extends ListView and the code for the adapter
itself is listed below:
public class OrderAdapter extends BaseAdapter{
private Context ctx;
private List<Order> orders;
public OrderAdapter(Context ctx, List<Order> orderLst){
this.ctx = ctx;
this.orders = orderLst;
}
#Override
public int getCount() {
return orders.size();
}
#Override
public Object getItem(int pos) {
return orders.get(pos);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
Order o = orders.get(position);
return new OrderListAdapterView(this.ctx,o);
}
}
When I debug I have the data inside my m_orders list but when I call
notifyDataSetChanged nothing happens, I've read that I have to execute that
on the UI thread which I think I do. So whats the problem ?
any help highly appreciated, or maybe just a link to the nice tutorial on
the web explaining this issue on how to update the list view at runtime ?
Hey Arutha - why don't you see my answer for this post - I think it is what you need.
Or just let me repost it here
You can extend ArrayAdapter. Here's code example for you. In this example - SearchItem is some custom POJO. Basically you need to override getView() method to build your row by inflating row layout and then populating values based on List of items and current position
class SearchItemsAdapter extends ArrayAdapter<SearchItem> {
Activity context;
List<SearchItem> items;
SearchHeader header;
#SuppressWarnings("unchecked")
public SearchItemsAdapter(final Activity context,
final Map<SearchHeader, List<SearchItem>> result) {
super(context, R.layout.item, (List) ((Object[]) result.values()
.toArray())[0]);
this.context = context;
this.header = result.keySet().iterator().next();
this.items = result.get(this.header);
}
#Override
public View getView(final int position, final View convertView,
final ViewGroup parent) {
final View view = this.context.getLayoutInflater().inflate(
R.layout.item, null);
final SearchItem item = this.items.get(position);
((TextView) view.findViewById(R.id.jt)).setText(item.jt);
((TextView) view.findViewById(R.id.dp)).setText(item.dp);
((TextView) view.findViewById(R.id.cn)).setText(item.cn);
((TextView) view.findViewById(R.id.loc)).setText(item.loc.name);
final TextView body = ((TextView) view.findViewById(R.id.e));
body.setText(item.e);
body.setTag(item.src[0]);
((TextView) view.findViewById(R.id.src)).setText(item.src[1]);
return view;
}
}

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