I started using fragments to develop a new app, one of the fragments is a ListFragment,
when I use the adapter I made to show the list's rows I get some null from some findViewById that I use on the getView() method.
The structure is:
activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<FrameLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:id="#+id/fragment_container">
</FrameLayout>
</RelativeLayout>
frag_detail.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#android:id/list"
android:layout_gravity="center"/>
</LinearLayout>
detail_list_item.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/detailItemLayout" >
<ImageButton
android:layout_width="64dp"
android:layout_height="64dp"
android:id="#+id/imgIcon"
android:layout_below="#+id/txtTitle"
android:layout_centerHorizontal="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:text="txtTitle"
android:id="#+id/txtTitle"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceSmall"
android:text="label1"
android:id="#+id/label1"
android:layout_below="#+id/imgIcon"
android:layout_alignParentLeft="true"/>
</RelativeLayout>
DetailFragment class
public class DetailFragment extends ListFragment {
private Context context;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.frag_detail,container,false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
MonsterDataSource ds = new MonsterDataSource(context);
List<Monster> lsMonster = ds.getAllMonsters();
//ListView lsView = (ListView)this.getActivity().findViewById(R.id.lsDetail);
MonsterListAdapter adapter = new MonsterListAdapter(context,lsMonster);
//lsView.setAdapter(adapter);
setListAdapter(adapter);
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
context = activity.getApplicationContext();
}
}
And the MonsterListAdapter class
public class MonsterListAdapter extends BaseAdapter {
static class ViewHolder {
private TextView txtTitle;
private ImageView imgIcon;
private TextView txtHealth;
}
private Context context;
private LayoutInflater inflater;
private List<Monster> data;
private ViewHolder holder;
public MonsterListAdapter(Context c, List<Monster> data){
context = c;
this.data = data;
inflater = (LayoutInflater)c.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
/*Basic BaseAdapter Methods*/
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if (view == null) {
view = inflater.inflate(R.layout.menu_list_item, null);
holder = new ViewHolder();
/*Those Guys get null*/
RelativeLayout layout = (RelativeLayout)view.findViewById(R.id.detailItemLayout);
holder.txtTitle = (TextView) view.findViewById(R.id.txtTitle);
holder.imgIcon = (ImageView) view.findViewById(R.id.imgIcon);
view.setTag(holder);
} else {
holder = (ViewHolder) view.getTag();
}
Monster monster = data.get(i);
holder.txtTitle.setText(monster.name);
holder.imgIcon.setImageResource(monster.imgResID);
holder.txtHealth.setText(monster.health);
return view;
}
}
In case anyone asking, I'm trying to retrieve the relative layout to add some controls dynamically after.
Thanks
You posted the XML for detail_list_item.xml but in your code you inflate menu_list_item.xml.
detail_list_item.xml contains all of the IDs you are trying to find so it appears you have accidentally inflated the wrong View in getView
Additionally, you should remove your ViewHolder as a member variable and place it as a local variable in the getView method. You are reusing that variable for multiple views at the same time which means you have the potential for modifying the wrong views at different positions (data going to the wrong positions, etc).
public View getView(int i, View view, ViewGroup viewGroup) {
ViewHolder holder;
...
...//all of your other code here
}
Try without affecting "view"
RelativeLayout layout = (RelativeLayout)findViewById(R.id.detailItemLayout);
holder.txtTitle = (TextView) findViewById(R.id.txtTitle);
holder.imgIcon = (ImageView) findViewById(R.id.imgIcon);
Edit This works for me... My texviews nbCommentaires and Comment give NullPointerException if i inflate View to them... I thought you get the same issue...
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
if (v == null) {
LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.comment_row, null);
}
v.setTag(position);
Commentaires o = Global_reco.CommRecos.get(position);
if (o != null) {
TextView nom = (TextView) v.findViewById(R.id.nom_com);
TextView com = (TextView) v.findViewById(R.id.com);
ImageView photo = (ImageView) v.findViewById(R.id.profile_com);
TextView nbCommentaires = (TextView) findViewById(R.id.nb_commentaires);
TextView Comment = (TextView)findViewById(R.id.nbre_comment);
photo.setTag(position);
Related
Trying to implement a onlick functionality for the android listview but something seems to not working. I tried to find some solutions over the internet and I found that there were recommendation to change the focusable property of imageview and textview elements. Tried it and it did not work. Appreciate if you guys can recommend any other alternatives.
Layout item.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
android:id="#+id/rootItemId"
android:clickable="true"
android:gravity="center_vertical">
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:focusable='false'
android:background="#drawable/frame">
<ImageView
android:id="#+id/ivIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:contentDescription="#string/hello_world"
android:padding="5dp"
android:focusable='false'
android:src="#drawable/ic_launcher"
android:scaleType="fitXY"/>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:focusable='false'
android:layout_toRightOf="#id/ivIcon">
<TextView
android:id="#+id/tvTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:focusable='false'
android:textAppearance="#android:style/TextAppearance.Medium"/>
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
list fragment
public class EventsListFragment extends ListFragment{
ArrayList<Event> eventsChildren;
#Override
public void onListItemClick(ListView l, View v, int position, long id) {
Log.e("RedditListingsClick",position + " " + id);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
eventsChildren = new ArrayList<Event>();
EventsChildAdapter adapter = new EventsChildAdapter(inflater.getContext(), eventsChildren);
setListAdapter(adapter);
return super.onCreateView(inflater, container, savedInstanceState);
}
}
list adapter
public class EventsChildAdapter extends ArrayAdapter<Event> {
Context context;
RelativeLayout root;
private static class ViewHolder {
TextView title;
ImageView thumbnail;
}
public EventsChildAdapter(Context context, ArrayList<Event> eventsChildren) {
super(context, R.layout.item_listing, eventsChildren);
this.context = context;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
Event child = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
ViewHolder viewHolder; // view lookup cache stored in tag
if (convertView == null) {
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.item_listing, null);
//root=(RelativeLayout)convertView.findViewById(R.id.rootItemId);
viewHolder.title = (TextView) convertView.findViewById(R.id.tvTitle);
//viewHolder.thumbnail = (ImageView) convertView.findViewById(R.id.ivIcon);
convertView.setTag(viewHolder);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
// Populate the data into the template view using the data object
System.out.println(child.getTitle());
viewHolder.title.setText(child.getTitle());
Picasso.with(this.context).load(child.getThumbnailImageURL()).resize(200, 100).into(viewHolder.thumbnail);
// Return the completed view to render on screen
return convertView;
}
}
In addition to the above, I have already tried adding android:descendantFocusability="blocksDescendants" to relativelayout but still did not work. Finally I tried to make the root relativelayout clickable and removed focus from the other elements and this did not work either.
You can try this:
public class EventsListFragment extends ListFragment implement OnItemClickListener {
...
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,long id) {
// the child callback here.
}
}
and this in onActivityCreated
setListAdapter(Your adapter);
getListView().setOnItemClickListener(this);
Hellow i've implemented ListView inside the CardView but now what problem i got is, the CardView is not Expanding on Adding list item. Can anybody help me,how to slove the issue? I have gone through different posts on stackoverflow but cannot find the solution :( My code is below
//this is my Listview adapter Class
public class EmploymentHistoryAdapter extends BaseAdapter {
public ArrayList<EmploymentHistory> mEmploymentHistories;
private Context context;
public EmploymentHistoryAdapter(ArrayList<EmploymentHistory> mEmploymentHistories, Context context) {
this.mEmploymentHistories = mEmploymentHistories;
this.context = context;
}
#Override
public int getCount() {
return mEmploymentHistories.size();
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return 0;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = null;
EmploymentHistory empHistory = mEmploymentHistories.get(position);
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.list_employee_history_row, parent, false);
} else {
v = convertView;
}
TextView hospital = (TextView) v.findViewById(R.id.hospital);
TextView department = (TextView) v.findViewById(R.id.department);
TextView startDate = (TextView) v.findViewById(R.id.startDate);
TextView endDate = (TextView) v.findViewById(R.id.endDate);
TextView hospitalName = (TextView) v.findViewById(R.id.hospitalName);
hospitalName.setText(empHistory.getHospital());
TextView departmentName = (TextView) v.findViewById(R.id.departmentName);
departmentName.setText(empHistory.getDepartment());
TextView startDate1 = (TextView) v.findViewById(R.id.startDate1);
startDate1.setText(empHistory.getStartDate());
TextView endDate1 = (TextView) v.findViewById(R.id.endDate1);
endDate1.setText(empHistory.getEndDate());
hospital.setVisibility(View.VISIBLE);
department.setVisibility(View.VISIBLE);
startDate.setVisibility(View.VISIBLE);
endDate.setVisibility(View.VISIBLE);
return v;
}
}
//this is where i populated the ListView
private void populateEmploymentHistoryList() {
listEmployeeHistory = (ListView) findViewById(R.id.listEmployeeHistory);
empHistory = dbHelper.getAllEmploymentHistory();
employmentHistoryAdapter = new EmploymentHistoryAdapter(empHistory,this);
listEmployeeHistory.setAdapter(employmentHistoryAdapter);
}
//this is my Layout file where i added the ListView and I have the custom design for list_row
<android.support.v7.widget.CardView
android:id="#+id/employmentHistoryCard"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginBottom="#dimen/card_margin"
android:layout_marginLeft="#dimen/card_margin"
android:layout_marginRight="#dimen/card_margin">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="#+id/employmentHistory"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="#E0E0E0"
android:gravity="center"
android:text="Employment History"
android:textAppearance="#style/TextAppearance.AppCompat.Title"
android:textColor="#4A148C" />
<TextView
android:id="#+id/addEmployment"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/employmentHistory"
android:layout_marginTop="15dp"
android:background="?attr/selectableItemBackground"
android:clickable="true"
android:drawableLeft="#drawable/ic_add"
android:drawablePadding="20dp"
android:drawableStart="#drawable/ic_add"
android:paddingLeft="30dp"
android:text="Add Employment"
android:textColor="#0e89d0" />
<ListView
android:id="#+id/listEmployeeHistory"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/addEmployment">
</ListView>
</RelativeLayout>
</android.support.v7.widget.CardView>
You need to specify certain height for ListView in the xml code. WRAP_CONTENT will not expand your ListView when data is inflated into it. Specify some height like 200dp or something.
I created my own custom adapter that extends Array Adapter:
public class AdapterGeoArea extends ArrayAdapter<GeoArea>{
private Context _context;
private int resource;
private ArrayList<GeoArea> _myGeoArea;
public AdapterGeoArea(Context context, ArrayList<GeoArea> myGeoArea) {
super(context, 0, myGeoArea);
_context = context;
_myGeoArea = myGeoArea;
}
public int getCount() {
return _myGeoArea.size();
}
public View getView(int position, View convertView, ViewGroup parent) {
LinearLayout GeoAreaView;
if (convertView == null) {
GeoAreaView = new LinearLayout(_context);
LayoutInflater li = LayoutInflater.from(_context);
convertView = li.inflate(R.layout.layout_geo_areas, null);
}
else {
GeoAreaView = (LinearLayout) convertView;
}
GeoArea curGeoArea = _myGeoArea.get(position);
TextView name = (TextView) GeoAreaView.findViewById(R.id.txtGeoAreaName);
name.setText(curGeoArea.name);
return convertView;
}
static class ViewHolder {
TextView name;
RelativeLayout childContainer;
}
#Override
public Filter getFilter() {
return null;
}
}
And here is how I am using it in my main:
public class ActivityGeoAreas extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_geo_areas);
GeoArea.searchTerm = "Bar & Grill";
GeoArea torontoArea = new GeoArea("cityOfToronto");
ArrayList<GeoArea> testList = new ArrayList<GeoArea>();
testList.add(torontoArea);
AdapterGeoArea adapter = new AdapterGeoArea(this, testList);
ListView lv = (ListView) findViewById(R.id.textGeoArea);
lv.setAdapter(adapter);
}
}
Everything seem to be fine except for this line:
TextView name = (TextView) GeoAreaView.findViewById(R.id.textGeoArea);
And here is how I defined my layout:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context=".ActivityGeoAreas" >
<TextView
android:id="#+id/textGeoArea"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:text="Choose Area"
android:textAppearance="?android:attr/textAppearanceLarge" />
<LinearLayout
android:id="#+id/LinearLayoutGeoAreas"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/textGeoArea"
android:layout_below="#+id/textGeoArea"
android:orientation="vertical" >
<ListView
android:id="#+id/listViewGeoArea"
android:layout_width="wrap_content"
android:layout_height="match_parent" >
</ListView>
</LinearLayout>
</RelativeLayout>
It simply can't find the TextView textGeoArea and this line become null, what am I doing wrong?
Change this
TextView name = (TextView) GeoAreaView.findViewById(R.id.txtGeoAreaName);
to
TextView name = (TextView) convertView.findViewById(R.id.txtGeoAreaName);
I guess you have got confused.
Move textview to a new layout list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/textGeoArea"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="14dp"
android:text="Choose Area"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
Now change your getView as below
LayoutInflater inflater;
public AdapterGeoArea(Context context, ArrayList<GeoArea> myGeoArea) {
super(context, 0, myGeoArea);
_context = context;
_myGeoArea = myGeoArea;
inflater = LayoutInflater.from(context); // initialize inflater
}
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_row,parent,false);
holder = new ViewHolder();
holder.tv = (TextView)convertView.findViewById(R.id.textGeoArea);
holder.setTag(convertView);
}
else {
holder = (ViewHolder) convertView.getTag();
}
GeoArea curGeoArea = _myGeoArea.get(position);
holder.tv.setText(curGeoArea.name);
return convertView;
}
static class ViewHolder // use a view holder for smooth scrolling an performance
{
TextView tv;
}
On the first pass, GeoAreaView is a childless LinearLayout since you just created it. convertView is the View initialized your layout which holds the TextView. So you need to use that to find the TextView.
TextView name = (TextView) convertView.findViewById(R.id.txtGeoAreaName);
I see you have a ViewHolder but you don't appear to be using it. You may want to take a little time and go through a good tutorial on using ListView.
This guy usually seems to have good tutorials
I created this class called GeoArea, which is suppose to store "Geographical Area" that have children Geographical Areas, this is fairly strait foward:
public class GeoArea {
public String id;
public String name;
public List<GeoArea> subGeoAreas;
public GeoArea parentGeoArea;
public GeoArea(String id) {
this.id = id;
name = id;
subGeoAreas = new LinkedList<GeoArea>();
}
#Override
public String toString() {
return name;
}
}
I have created the following Layout to render it on Android, the idea here is to for each GeoArea to recursively render it self and then it's children GeoArea in a listView:
//layout_geo_area.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/txtGeoAreaName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:gravity="left"
android:text="Geo Area Name"
android:textAppearance="?android:attr/textAppearanceLarge" />
<ListView
android:id="#+id/listViewChildGeoAreas"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="#+id/txtGeoAreaName"
android:gravity="left" >
</ListView>
</RelativeLayout>
This is my adapter I created for GeoArea to be displayed in a listView:
public class AdapterGeoArea extends ArrayAdapter<GeoArea>{
private ArrayList<GeoArea> _myGeoArea;
private Context _myContext;
LayoutInflater _inflater;
public AdapterGeoArea(Context context, ArrayList<GeoArea> myGeoArea) {
super(context, 0, myGeoArea);
_myGeoArea = myGeoArea;
_inflater = LayoutInflater.from(context);
_myContext = context;
}
public int getCount() {
return _myGeoArea.size();
}
public View getView(int position, View convertView, ViewGroup parent) {
GeoAreaLayoutHolder holder;
if (convertView == null) {
convertView = _inflater.inflate(R.layout.layout_geo_area,parent,false);
holder = new GeoAreaLayoutHolder();
holder.txtGeoAreaName = (TextView)convertView.findViewById(R.id.txtGeoAreaName);
holder.txtGeoAreaName.setTag(convertView);
holder.listViewChildGeoAreas = (ListView)convertView.findViewById(R.id.listViewChildGeoAreas);
holder.listViewChildGeoAreas.setTag(convertView);
} else {
holder = (GeoAreaLayoutHolder) convertView.getTag();
}
GeoArea curGeoArea = _myGeoArea.get(position);
holder.txtGeoAreaName.setText(curGeoArea.name);
if(curGeoArea.subGeoAreas.size()>0){
ArrayList<GeoArea> testList = new ArrayList<GeoArea>();
AdapterGeoArea adapter = new AdapterGeoArea(_myContext, testList);
for(GeoArea childGeoArea:curGeoArea.subGeoAreas){
testList.add(childGeoArea);
}
holder.listViewChildGeoAreas.setAdapter(adapter);
}
return convertView;
}
static class GeoAreaLayoutHolder {
public TextView txtGeoAreaName;
public ListView listViewChildGeoAreas;
}
}
And here is my Activity that I am using to set it all up:
public class ActivityGeoAreas extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.layout_geo_area);
GeoArea.searchTerm = "Bar & Grill";
GeoArea torontoArea = new GeoArea("cityOfToronto");
ArrayList<GeoArea> testList = new ArrayList<GeoArea>();
testList.add(torontoArea);
AdapterGeoArea adapter = new AdapterGeoArea(this, testList);
ListView lv = (ListView) findViewById(R.id.listViewChildGeoAreas);
lv.setAdapter(adapter);
}
}
When I try to run it, I get the error nullPointerException on the line:
holder.txtGeoAreaName.setText(curGeoArea.name);
What am I doing wrong?
You may want to check ExpandableListView may suit your needs better
http://developer.android.com/reference/android/widget/ExpandableListView.html
An example # http://www.androidhive.info/2013/07/android-expandable-list-view-tutorial/
Continuing from my previous answer to your question ( i though that solved your problem)
To display just name in your listview
list_row.xml // this is the layout with textview to be inflated in getView.
Each row will have textview
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<TextView
android:id="#+id/textGeoArea"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:layout_marginTop="14dp"
android:text="Choose Area"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
layout_geo_area.xml // with only listview no textview
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ListView
android:id="#+id/listViewChildGeoAreas"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:gravity="left" >
</ListView>
</RelativeLayout>
Now your adapter class
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.list_row,parent,false);
// inflate list_row.xml with textview
holder = new ViewHolder();
holder.tv = (TextView)convertView.findViewById(R.id.textGeoArea);
holder.setTag(convertView);
}
else {
holder = (ViewHolder) convertView.getTag();
}
GeoArea curGeoArea = _myGeoArea.get(position);
holder.tv.setText(curGeoArea.name);
return convertView;
}
static class ViewHolder // use a view holder for smooth scrolling an performance
{
TextView tv;
}
You have a custom adapter.
public class AdapterGeoArea extends ArrayAdapter<GeoArea>{
Now you set the adapter to listview like below
AdapterGeoArea adapter = new AdapterGeoArea(this, testList);
ListView lv = (ListView) findViewById(R.id.listViewChildGeoAreas);
lv.setAdapter(adapter);
So why do you need the below. remove these
if(curGeoArea.subGeoAreas.size()>0){
ArrayList<GeoArea> testList = new ArrayList<GeoArea>();
AdapterGeoArea adapter = new AdapterGeoArea(_myContext, testList);
for(GeoArea childGeoArea:curGeoArea.subGeoAreas){
testList.add(childGeoArea);
}
holder.listViewChildGeoAreas.setAdapter(adapter);
I am using the following code.
Adapter.java class
public class Adapter extends ArrayAdapter<String> {
private java.util.List<String> List;
private Context context;
public Adapter(List<String> list, Context ctx) {
super(ctx, R.layout.row_item, list);
this.List = list;
this.context = ctx;
}
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
NameHolder holder = new NameHolder();
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.row_item, null);
TextView tv = (TextView)v.findViewById(R.id.textView1);
LinearLayout ll = (LinearLayout) v.findViewById(R.id.myLayout);
holder.topic_name = tv;
holder.myLayout = ll;
v.setTag(holder);
}
else
holder = (NameHolder) v.getTag();
String topic = List.get(position);
holder.topic_name.setText(topic);
ImageView imgUsers = new ImageView(context);
imgUsers.setImageResource(R.drawable.ic_launcher);
holder.myLayout.addView(imgUsers);
return v;
}
private static class NameHolder {
public TextView topic_name;
public LinearLayout myLayout;
}
}
MainActivity.java class :
public class MainActivity extends Activity {
ListView lv;
ArrayList<String> list;
Adapter myAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
lv = (ListView)findViewById(R.id.listView1);
list = new ArrayList<String>();
for(int i=0; i<10;i++){
list.add("Name"+i);
}
myAdapter = new Adapter(list, MainActivity.this);
lv.setAdapter(myAdapter);
lv.setOnItemClickListener(new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Toast.makeText(MainActivity.this,"lets see"+list.get(arg2), Toast.LENGTH_SHORT).show();
}
});
}
}
activity_main.xml :
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ListView
android:id="#+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
row_item.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Large Text"
android:textAppearance="?android:attr/textAppearanceLarge" />
<HorizontalScrollView
android:id="#+id/horizontalScrollView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:orientation="horizontal"
android:id="#+id/myLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
></LinearLayout>
</HorizontalScrollView>
</LinearLayout>
Now, the expected output is a single image in every listItem, which tend to go to infinite.
And the onItemClickListener is not working as well.
Also, onItemClickListener works if we don't add HorizontalScrollView.
Writing onClickListener() in Adapter itself helps little as it works unpredictably.
Also, on adding a print statement in getView() and observing in Logcat, I find it difficult to understand the pattern in which getView() is called.
These are the problems I face. I require a working code of the things I wish to apply. Thanks in advance.
// Replace this code
public View getView(int position, View convertView, ViewGroup parent) {
NameHolder holder;
if (convertView == null) {
holder = new NameHolder();
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.row_item, null);
holder.topic_name = (TextView)convertView.findViewById(R.id.textView1);
holder.myLayout = (LinearLayout) convertView.findViewById(R.id.myLayout);
convertView.setTag(holder);
}
else
holder = (NameHolder) convertView.getTag();
String topic = List.get(position);
holder.topic_name.setText(topic);
ImageView imgUsers = new ImageView(context);
imgUsers.setImageResource(R.drawable.ic_launcher);
holder.myLayout.removeAllViews();
holder.myLayout.addView(imgUsers);
convertView.setTag(holder);
return convertView;
}
Looks like you are adding an ImageView every single time here
ImageView imgUsers = new ImageView(context);
imgUsers.setImageResource(R.drawable.ic_launcher);
holder.myLayout.addView(imgUsers);
Why don't you include the ImageView as part of your list item layout?