Develop Reference

String Array data not showing in TextView

I'm in the process of learning android app development however I have come to an impasse. My RecyclerView is picking up how many items are in my String array however it is not showing the actual data in text1, any help would be much appreciated.
This is my adapter
public class EventCalenderAdapter extends RecyclerView.Adapter<EventCalenderAdapter.ViewHolder> {
static String[] fakeData = new String[] {
"One","Two","Three","Four","Five","Ah..Ah..Ah"
};
static class ViewHolder extends RecyclerView.ViewHolder {
CardView cardView;
TextView titleView;
public ViewHolder(CardView card) {
super(card);
cardView = card;
titleView = (TextView) card.findViewById(R.id.text1);
}
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int i) {
CardView v = (CardView) LayoutInflater.from(parent.getContext()).inflate(R.layout.event_task, parent, false);
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(ViewHolder viewHolder, int i) {
viewHolder.titleView.setText(fakeData[i]);
}
#Override
public int getItemCount() {
return fakeData.length;
}
This is the corresponding XML
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:event_view="http://schemas.android.com/apk/res-auto"
android:layout_height="100dp"
android:layout_width="match_parent"
android:id="#+id/event_view"
android:layout_marginTop="#dimen/task_card_half_spacing"
android:layout_marginBottom="#dimen/task_card_half_spacing"
android:layout_marginLeft="#dimen/gutter"
android:layout_marginRight="#dimen/gutter"
android:layout_gravity="center"
android:elevation="#dimen/task_card_elevation"
android:foreground="?android:attr/selectableItemBackground"
event_view:cardCornerRadius="0dp" >
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:layout_width="100dp"
android:layout_height="100dp"
android:id="#+id/image"
android:scaleType="centerCrop"
android:layout_alignParentLeft="true"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
style="#android:style/TextAppearance.Medium.Inverse"
android:id="#+id/text1"
android:maxLines="1"
android:ellipsize="end"
android:padding="10dp"
android:layout_alignTop="#+id/image"
android:layout_toRightOf="#+id/image"/>
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
style="#android:style/TextAppearance.Inverse"
android:id="#+id/text2"
android:maxLines="3"
android:ellipsize="end"
android:padding="10dp"
android:layout_alignStart="#+id/text1"
android:layout_below="#+id/text1"/>
</RelativeLayout>
</android.support.v7.widget.CardView>
and this is my fragment
public class EventCalenderFragment extends Fragment {
RecyclerView recyclerView;
EventCalenderAdapter adapter;
public EventCalenderFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
adapter = new EventCalenderAdapter();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = inflater.inflate(R.layout.fragment_event_calender, container, false);
recyclerView = (RecyclerView) v.findViewById(R.id.recycler);
recyclerView.setAdapter(adapter);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
return v;
}

Hm... everything looks ok, can you try setting this to it:
android:textColor="#000000"

Spinner BaseAdapter(android)

Sorry for my English. As research, I want to try to use the spinner with baseAdapter. But I do not know why I spinner does not output anything.
Its xml:
student_list_questions.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" >
<ListView
android:id="#+id/listsQuestions"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp" >
</ListView>
</LinearLayout>
student_list.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:layout_margin="10dp"
android:orientation="vertical"
>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="#+id/s_textQuestions"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="0.5"
android:paddingBottom="5dp"
android:paddingTop="5dp"
android:textColor="#7F8C8D"
android:textSize="16dp" />
<Spinner
android:id="#+id/s_spinner_rating"
android:layout_width="90dp"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical" />
</LinearLayout>
</LinearLayout>
And my Class:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.student_list_questions);
Spinner sp = new Spinner(this);
SpinnerBaseAdapter adapter = new SpinnerBaseAdapter(this, new ArrayList<String>());
sp.setAdapter(adapter);
//then code
}
And this spinner adapter:
public class SpinnerBaseAdapter extends BaseAdapter {
private List<String> numberList;
private LayoutInflater mInflater;
#SuppressWarnings("unchecked")
public SpinnerBaseAdapter(Context context, Object results) {
numberList = (List<String>) results;
numberList.add("1");
numberList.add("2");
numberList.add("3");
mInflater = LayoutInflater.from(context);
}
#Override
public int getCount() {
return numberList.size();
}
#Override
public Object getItem(int position) {
return numberList.get(position);
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
ViewHolder holder;
if(convertView == null) {
convertView = mInflater.inflate(R.layout.student_list, null);
holder = new ViewHolder();
holder.spinnerValue = (TextView) convertView.findViewById(R.id.s_spinner_rating);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}
holder.spinnerValue.setText(numberList.get(position));
return convertView;
}
static class ViewHolder {
TextView spinnerValue;
}
}

NullPointException in ListView when getting button

I am having a weird problem and can't seem to find whats causing it. Every view component in my ArrayAdapter is being located in the getView method except my button which is causes a NullPointerException.
Adapter:
public class ItemAdapter extends ArrayAdapter<Item>{
private Context context;
private int resource;
private List<Item> list;
public ItemAdapter(Context context, int resource, List<Item> list)
{
super(context, resource, list);
this.context = context;
this.resource = resource;
this.list = list;
}
#Override
public View getView(int position, View convertView, ViewGroup parent)
{
if (convertView == null)
convertView = LayoutInflater.from(context).inflate(resource, parent,false);
TextView name = (TextView) convertView.findViewById(R.id.itemName);
ImageView itemImg = (ImageView) convertView.findViewById(R.id.itemImg);
Button addToCart = (Button) convertView.findViewById(R.id.button1);
final Item item = list.get(position);
name.setText(item.getName());
UrlImageViewHelper.setUrlDrawable(itemImg, item.getPicture());
addToCart.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View view)
{
Toast.makeText(context, "Clicked", Toast.LENGTH_LONG).show();
}
});
return convertView;
}
}
Fragment with listview
#InjectView(R.id.itemList) private ListView listView;
#Inject private ItemDao dao;
private ArrayAdapter<Item> adapter;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_shop, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState)
{
super.onViewCreated(view, savedInstanceState);
dao.open();
List<Item> items = dao.findAll();
dao.close();
adapter = new ItemAdapter(getActivity(),R.layout.list_product_item, items);
listView.setAdapter(adapter);
}
list_product_item
<?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="horizontal"
android:paddingBottom="5dp"
android:paddingLeft="10dp"
android:paddingRight="10dp"
android:paddingTop="5dp" >
<ImageView
android:id="#+id/itemImg"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_marginRight="5dp"
android:scaleType="centerCrop" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/itemName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Medium Text"
android:textAppearance="?android:attr/textAppearanceMedium" />
<TextView
android:id="#+id/itemStoreName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TextView" />
<Button
android:id="#+id/button1"
style="?android:attr/buttonStyleSmall"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
Now the call to convertView.findViewById(R.id.button1) returns a null instance. What is the cause of this and how can I fix it.

do you have right the name of the layout?
adapter = new GroceryItemAdapter(getActivity(), R.layout.list_textview, items);
vs.
list_product_item
(I am assuming this is the file name for R.layout.list_product_item)

Instead of getting the layout inflater using the from method try initializing the inflater in the constructor..
mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
in the getView
convertView = mInflater.inflate(your layout, null);

Fragment and Adapter in Android App Not Displaying Data

I'm really new in Android. I have this problem, I have an Activity (MainActivity) and there is a NavigationDrawer, this switches two fragments - ActivitiesFragment and ReportFragments.
The problem is with ActivitiesFragments, data is not displayed.
I have my adapter ready and my layouts ready and the fragment. When I debugg my app, it actually brings data, but is not shown. This is my code:
ActivitiesAdapter
public class ActivitiesAdapter extends ArrayAdapter<Activities>
{
Context mContext;
int mLayoutResourceId;
public ActivitiesAdapter(Context context, int layoutResourceId)
{
super(context, layoutResourceId);
mContext = context;
mLayoutResourceId = layoutResourceId;
}
public View getView(int position, View convertView, ViewGroup parent)
{
View row = convertView;
final Activities currentItem = getItem(position);
if (row == null)
{
LayoutInflater inflater = ((Activity) mContext).getLayoutInflater();
row = inflater.inflate(mLayoutResourceId, parent, false);
}
row.setTag(currentItem);
final TextView tituloview = (TextView) row.findViewById(R.id.tituloAct);
tituloview.setText(currentItem.getTitle());
final TextView descrpview = (TextView) row.findViewById(R.id.descrAct);
descrpview.setText(currentItem.getDescription());
return row;
}
}
This is my fragment ActivitiesFragment
public class ActivitiesFragment extends Fragment
{
protected static final String TAG = "ActivitiesFragmment";
private MobileServiceClient mClient;
private MobileServiceTable<Activities> mActivitiesTable;
private ActivitiesAdapter mAdapter;
#Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.act_listfragment, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState)
{
super.onActivityCreated(savedInstanceState);
try
{
mClient = new MobileServiceClient("https://site.azure-mobile.net/",
"APPLICATIONKEYAPPLICATIONKEY",
getActivity().getApplicationContext()).withFilter(new ProgressFilter());
mActivitiesTable = mClient.getTable(Activities.class);
}
catch (MalformedURLException e)
{
createAndShowDialog(new Exception("There was an error creating the Mobile Service. Verify the URL"), "Error");
}
mAdapter = new ActivitiesAdapter(getActivity(), R.layout.act_itemlist);
ListView listViewToDo = (ListView) getView().findViewById(R.id.activities_fragment_list);
listViewToDo.setAdapter(mAdapter);
refreshItemsFromTable();
}
private void createAndShowDialog(Exception exception, String title)
{
createAndShowDialog(exception.toString(), title);
}
private void createAndShowDialog(String message, String title)
{
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity().getApplicationContext());
builder.setMessage(message);
builder.setTitle(title);
builder.create().show();
}
private void refreshItemsFromTable()
{
mActivitiesTable.execute(new TableQueryCallback<Activities>()
{
public void onCompleted(List<Activities> result, int count, Exception exception, ServiceFilterResponse response) {
if (exception == null) {
mAdapter.clear();
for (Activities item : result) {
mAdapter.add(item);
Log.i(TAG, "Titulo: " + item.getTitle());
}
} else {
createAndShowDialog(exception, "Error");
}
}
});
}
}
I don't know whats wrong, but I guess this block is not working on the OnActivityCreated method:
mAdapter = new ActivitiesAdapter(getActivity(), R.layout.act_itemlist);
ListView listViewToDo = (ListView) getView().findViewById(R.id.activities_fragment_list);
listViewToDo.setAdapter(mAdapter);
refreshItemsFromTable();
And here are my Layouts:
This is my frgament's layout:
<LinearLayout 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:background="#e1e1e1"
android:orientation="vertical" >
<TextView
android:id="#+id/tvTituloActs"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/all_activities"
android:layout_marginLeft="16dp"
android:layout_marginTop="8dp"
android:textColor="#009ad2"
android:textAppearance="?android:attr/textAppearanceMedium" />
<ListView android:id="#+id/activities_fragment_list"
android:layout_marginTop="8dp"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#FFFFFF"
android:layout_weight="1"
tools:listitem="#layout/act_itemlist"
android:drawSelectorOnTop="false"/>
<TextView android:id="#id/android:empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No hay datos"/>
</LinearLayout>
This is the layout act_itemlist. The row layout:
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="64dp"
android:orientation="horizontal">
<ImageView
android:id="#+id/icon"
android:layout_width="32dp"
android:layout_height="32dp"
android:layout_marginLeft="8dp"
android:gravity="center_vertical"
android:src="#drawable/done"
android:layout_gravity="center_vertical"/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/tvTituloAct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:layout_marginTop="16dp"
android:textSize="16sp"/>
<TextView
android:id="#+id/tvDescrAct"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="8dp"
android:text="Description de la actividad" />
</LinearLayout>
</LinearLayout>
I really need help with this! Please if someone can see something that I'm missing please tell me!
Thanks!!!!

Try to swap these lines:
mAdapter = new ActivitiesAdapter(getActivity(), R.layout.act_itemlist);
ListView listViewToDo = (ListView) getView().findViewById(R.id.activities_fragment_list);
refreshItemsFromTable(); // populate first before attaching your adapter
listViewToDo.setAdapter(mAdapter);

I finally solved my problem. Everything was Ok, the only detail was the layout. It was on the fragments layout.
<TextView android:id="#id/android:empty"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="No hay datos"/>
This textview did not let to show the data so I deleted it and worked.
Thankk you for your help #LazyNinja

Android ListView based in custom BaseAdapter is not shown in my code

I've working on ListView with a custom BaseAdapter which I've watched on the Slidenerd tutorial series here:(It's not important to watch to understand my question)
http://www.youtube.com/watch?v=_l9e2t4fcfM&list=PLonJJ3BVjZW6hYgvtkaWvwAVvOFB7fkLa&index=91
After running the code on the virtual device there is no error but not ListView too.
Is it possible to tell me what's the problem of my code?
public class List extends Activity {
ListView lv;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
lv = (ListView) findViewById(R.id.listView);
lv.setAdapter(new EhsanAdapter(this));
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.list, menu);
return true;
}
}
class SingleRow{
String title;
String description;
int image;
public SingleRow(String title,String description,int image) {
this.title = title;
this.description=description;
this.image=image;
}
}
class EhsanAdapter extends BaseAdapter{
ArrayList<SingleRow> list;
Context context;
public EhsanAdapter(Context c) {
list = new ArrayList<SingleRow>();
context = c;
Resources res = c.getResources();
String[] titles = res.getStringArray(R.array.titles);
String[] descriptions = res.getStringArray(R.array.descriptions);
int[] images = {R.drawable.image1,R.drawable.image2,R.drawable.image3,R.drawable.image4,R.drawable.image5};
for(int i=0;i<10;i++){
list.add(new SingleRow(titles[i], descriptions[i], images[i]));
}
}
#Override
public int getCount() {
return list.size();
}
#Override
public Object getItem(int i) {
return list.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View row = inflater.inflate(R.layout.single_row, viewGroup,false);
TextView title = (TextView) row.findViewById(R.id.txtTitle);
TextView description = (TextView) row.findViewById(R.id.txtDescription);
ImageView image = (ImageView) row.findViewById(R.id.imgPic);
SingleRow temp = list.get(i);
title.setText(temp.title);
description.setText(temp.description);
image.setImageResource(temp.image);
return row;
}
}
The layout of activity:
<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=".List" >
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/listView"/>
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="#string/hello_world" />
</RelativeLayout>
The layout of single row:
<?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" >
<ImageView
android:layout_margin="10dp"
android:id="#+id/imgPic"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:src="#drawable/image1" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Title"
android:id="#+id/txtTitle"
android:layout_alignTop="#+id/imgPic"
android:layout_toRightOf="#+id/imgPic"
android:layout_alignParentRight="true">
</TextView>
<TextView
android:id="#+id/txtDescription"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignTop="#+id/imgPic"
android:layout_marginLeft="25dp"
android:layout_toRightOf="#+id/imgPic"
android:layout_marginTop="20dp"
android:text="Description"
android:ems="10">
</TextView>
</RelativeLayout>

Remove the line LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); from getView() method and instead add it in the constructor of EhsanAdapter class.

I see different issues:
The layout of single row contains a relative layout which the android:layout_height="match_parent" should be android:layout_height="wrap_content"
Then inside the Adapter you are neither recycling the views nor using the ViewHolder pattern:
http://developer.android.com/training/improving-layouts/smooth-scrolling.html
About ViewHolder pattern implementation optimisation in ListView
http://www.jmanzano.es/blog/?p=166
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if (view == null){ //The row view is not created, let's do it:
LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View row = inflater.inflate(R.layout.single_row, viewGroup,false);
TextView title = (TextView) row.findViewById(R.id.txtTitle);
TextView description = (TextView) row.findViewById(R.id.txtDescription);
ImageView image = (ImageView) row.findViewById(R.id.imgPic);
// Here we add the title, description and image inside the ViewHolder
....
}else{
//With the View holder pattern we get the views inside the row view to fill it later
....
}
// Now we get the SingleRow and we fill it using the ViewHolder pattern
SingleRow temp = list.get(i);
....
return row;
}

You only have 5 images and you wrote i<10 you should've wrote i<5 the amount of "titles" and "descriptions" and "images" must be the same.
for(int i=0;i<5;i++){
list.add(new SingleRow(titles[i], descriptions[i], images[i]));
}