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.
Related
Suppose we have a list with several items. Each item has several fragments and a label within. When a user clicks on each label I need to change the text of the button1 that is out of the list view. How can I receive that label click event from inside of the list item and change a view that is out of the list view and list adapter.
I know how to handle internal events of the list view adapter inside the adapter. It's as simple as assigning the event handlers in GetView() method but they are not available out of the list.
Thanks for any help
Solved
I created a custom event and EventAgrs. When user clicks the label I invoke this event and in the main activity I handle the event and change the text of buton1. It was easier than I thought. In GetView() I assign the click event to the label_Click() event handler.
GetView(){
.
.
label.Click += label_Click();
.
.
}
In label_Click() I invoke the custom event that I have implemented before:
private void label_Click()(object sender, EventArgs e)
{
LabelClickedEvent.Invoke(sender, new LabelClickEventArgs("aaa", "bbb"));
}
In the list Adapter I declared this custom event: (For more information please look at this guide)
public event LabelClickedEventHandler LabelClickedEvent;
public delegate void LabelClickedEventHandler(object, sender,LabelClickEventArgs args);
public class LabelClickEventArgs : EventArgs
{
public string param1 { get; set; }
public string param2 { get; set; }
public LabelClickEventArgs(string param1 , string param2 )
{
this.param1 = param1 ;
this.param2 = param2 ;
}
}
In the main activity I simply assigned the event to my event handler and did whatever is needed.
listAdapter.LabelClickedEvent += listAdapter_LabelClickedEvent;
.
.
void listAdapter_LabelClickedEvent(object sender, TheListAdapter.LabelClickEventArgs args)
{
sendButton.Text = args.param1;
}
Hope it helps someone.
I do not know the proper way, but one way to do would be to implement the label item's OnClickListener() in the adapter, pass the reference of Button 1 to your adapter while creating an adapter, and then manipulate button 1 from OnClickListener().
public class MyAdapter extends BaseAdapter {
private Activity activity;
private ArrayList data;
private Button button1;
/************* CustomAdapter Constructor *****************/
public MyAdapter(Activity activity, ArrayList data, Button button1) {
this.data = data;
this.button1 = button1;
this.activity = activity;
inflater = (LayoutInflater) this.activity.
getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
public int getCount() {
if (data.size()<=0)
return 1;
return data.size();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public static class ViewHolder{
public TextView label1;
}
public View getView(int position, View convertView, ViewGroup parent) {
View vi = convertView;
ViewHolder holder;
if (convertView==null) {
vi = inflater.inflate(R.layout.list_item, null);
holder = new ViewHolder();
holder.label1 = (TextView)vi.findViewById(R.id.tvLabel1);
holder.label1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
this.button1.setText("Label 1 clicked");
}
});
vi.setTag(holder);
} else {
holder = (ViewHolder)vi.getTag();
}
// show the data in the list view
return vi;
}
}
Suppose you have a button 1 in MainActivity outside list view, so when you create adapter in MainActivity
on your MainActivity's onCreate method do following:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// define and initialize your data
Button button1 = (Button)findViewById(R.id.button1);
MyAdapter adapter = new MyAdapter(this, data, button1);
...
}
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<>();
}
I've listview in an activity and I want to append data at the top of it.When the activity loads the listview is populated.Now when the user clicks a button i am bringing additional data but i want this data to append at the top of the listview.How can I accomplish this?
I've the custom listview made using the baseAdapter .Heres my baseAdapter class:
public class LazyAdapterUserAdminChats extends BaseAdapter{
private Activity activity;
private ArrayList<HashMap<String,String>> hashmap;
private static LayoutInflater inflater=null;
public LazyAdapterUserAdminChats(Activity activity,ArrayList<HashMap<String,String>> hashMaps)
{
this.activity=activity;
this.hashmap=hashMaps;
LazyAdapterUserAdminChats.inflater=(LayoutInflater)this.activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return hashmap.size();
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View view=convertView;
if(convertView==null)
view=inflater.inflate(R.layout.useradminchat,null);
TextView username=(TextView)view.findViewById(R.id.UAC_userNametext);
TextView messagetext=(TextView)view.findViewById(R.id.UAC_messagetext);
TextView messageDate=(TextView)view.findViewById(R.id.UAC_dates);
HashMap<String,String> map=hashmap.get(position);
username.setText(map.get(HandleJSON.Key_username));
messagetext.setText(map.get(HandleJSON.Key_messageText));
messageDate.setText(map.get(HandleJSON.Key_messageDate));
return view;
}
}
Here's how I set the adapter for listview function from my activity.
private void ShowListView(ArrayList<HashMap<String,String>> chat)
{
try
{
ListView lv=(ListView)findViewById(android.R.id.list);
adapter = new LazyAdapterLatestChats(this,chat);
lv.setAdapter(adapter);
}
catch(Exception e)
{
Toast.makeText(this, e.getMessage(), Toast.LENGTH_LONG).show();
}
}
First of all, don't use a hashmap to hold your data. You'd much rather use an ArrayList, because you're going to be iterating. Hashmaps are usually used for fast information retrieval, and usually not for iteration (this can be done, though, with an Iterator).
Next, create a method on LazyAdapterUserAdminChats to add things to the head of your arraylist.
Lastly, call notifyDataSetChanged when you add to the head of the arraylist.
Example:
public class LazyAdapterUserAdminChats extends BaseAdapter{
private Activity activity;
private ArrayList<MyObj> al;
private static LayoutInflater inflater=null;
public LazyAdapterUserAdminChats(Activity activity,ArrayList<MyObj> al)
{
this.activity=activity;
this.al=al;
LazyAdapterUserAdminChats.inflater=(LayoutInflater)this.activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
// other methods
....
public void addToHead(MyObj m)
{
this.al.add(m, 0);
notifyDataSetChanged();
}
}
Your custom class can be anything you want. e.g.,
public class MyObj
{
String hashMapKey, hashMapValue;
}
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);
I am creating a contact list view, diplaying user name,user email and user id. Now while clicking on particular item i want to post some event to server based on the user id. How to get the user id inside the onClickItem listener, as user id is long value. i am able to get the user name that means the text but not the user id.
listView has onCLicklistener that has parameter position.If you are using arrayList to inflate ListView then you can use this positon to get corresponding object.
You can try to set the user id to tag using View.setTag and View.getTag. There are two version available choose the one you need. This way you can attach the user id as tag and then get it back.
http://developer.android.com/reference/android/view/View.html#setTag(int, java.lang.Object)
You code should look like:
view.setTag(Long.valueOf(id));
.....
onClickListener(..) {
Long id = (Long)view.getTag();
}
You should make your own bean class which contains your userid and put it in List (or ArrayList)
then create an adapter by creating a class extending ArrayAdapter (for instance) to bind your list of this bean class
register a listener either using onItemClickListener or View listener in your row if you inflate your custom layout.
get the position and use it to retrieve your userid on your bean list.
Here's my snippet
public class ListActivity extends Activity implements OnItemClickListener {
private Context context;
private RowAdapter adapter;
private ArrayList<Row> rowList = new ArrayList<Row>();
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
context = ListActivity.this;
initRows();
adapter = new RowAdapter(context, rowList);
ListView listView = (ListView) findViewById(R.id.listView);
listView.setAdapter(adapter);
listView.setOnItemClickListener(this);
}
private void initRows() {
Row row = new Row(1);
rowList.add(row);
row = new Row(2);
rowList.add(row);
}
public class Row {
long userid = 0;
public Row(long userid) {
this.userid = userid;
}
public long getUserid() {
return userid;
}
public void setUserid(long userid) {
this.userid = userid;
}
}
public class RowAdapter extends ArrayAdapter<Row> {
private Context context;
public RowAdapter(Context context, ArrayList<Row> bindList) {
super(context, R.layout.row_layout, bindList);
this.context = context;
}
#Override
public View getView(final int position, View convertView, ViewGroup parent) {
View view = convertView;
if(view == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.row_layout, null);
}
//if you use some additional View you can retrieve your position using this
Button button = view.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
updateSelected(position);
}
});
return view;
}
}
//or if you rather just listen on row click then you can retrieve your position using this
#Override
public void onItemClick(AdapterView<?> arg0, View view, int position, long arg3) {
updateSelected(position);
}
private void updateSelected(int position) {
rowList.get(position).getUserid();
//have it your way
}
}