We Keep Coding

Why is my view changing color upon reloading?

I am developing an android app, and need to use a recyclerview for it. I want its background to be white, but for some reason when I run the app it turns out gray. That being said, if I reload the activity, or go back and then again to the activity, the color does turn white. Has anyone ever encountered such a problem?
This is how it looks when you first enter the app
And this is what happens if you reload the activity.
Here's my item
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/trip"
android:layout_width="match_parent"
android:layout_height="70dp"
android:background="#null"
android:gravity="center"
android:orientation="horizontal">
<TextView
android:id="#+id/destination"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".333"
android:gravity="center"
android:textSize="24sp" />
<TextView
android:id="#+id/start_date"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".33"
android:gravity="center"
android:textSize="16sp"
app:layout_constraintStart_toEndOf="#+id/destination" />
<TextView
android:id="#+id/trip_length"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight=".333"
android:gravity="center" />
</LinearLayout>
and here is my main activity
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ImageView
android:id="#+id/imageView3"
android:layout_width="180dp"
android:layout_height="180dp"
android:contentDescription="#string/app_logo"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.0"
app:srcCompat="#drawable/app_logo" />
<TextView
android:id="#+id/main_name"
android:layout_width="359dp"
android:layout_height="26dp"
android:text="#string/welcome_message"
android:textSize="18sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.865"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.178" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/trips"
android:layout_width="350dp"
android:layout_height="wrap_content"
android:layout_marginBottom="80dp"
android:fadingEdge="horizontal|vertical"
android:maxHeight="200dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.491"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
This is my adapter
package com.alonkh2.finalproject;
import android.annotation.SuppressLint;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class TripAdapter extends RecyclerView.Adapter<TripAdapter.ViewHolder> {
private ArrayList<Trip> trips;
public class ViewHolder extends RecyclerView.ViewHolder {
// Your holder should contain a member variable
// for any view that will be set as you render a row
public TextView destination, startDate, endDate, length;
// We also create a constructor that accepts the entire item row
// and does the view lookups to find each subview
public ViewHolder(View itemView) {
// Stores the itemView in a public final member variable that can be used
// to access the context from any ViewHolder instance.
super(itemView);
destination = (TextView) itemView.findViewById(R.id.destination);
startDate = (TextView) itemView.findViewById(R.id.start_date);
// endDate = (TextView) itemView.findViewById(R.id.end_date);
length = (TextView) itemView.findViewById(R.id.trip_length);
}
}
public TripAdapter(ArrayList<Trip> trips) {
this.trips = trips;
}
#NonNull
#Override
public TripAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
Context context = parent.getContext();
LayoutInflater inflater = LayoutInflater.from(context);
// Inflate the custom layout
View contactView = inflater.inflate(R.layout.activity_listview, parent, false);
// Return a new holder instance
return new ViewHolder(contactView);
}
#SuppressLint("SetTextI18n")
#Override
public void onBindViewHolder(#NonNull TripAdapter.ViewHolder holder, int position) {
Trip trip = trips.get(position);
// Set item views based on your views and data model
TextView textView = holder.destination;
textView.setText(trip.getDestination());
textView = holder.startDate;
textView.setText(trip.getStrStartDate().substring(0, trip.getStrStartDate().indexOf(" ")));
// textView = holder.endDate;
// textView.setText(trip.getStrEndDate().substring(0, trip.getStrEndDate().indexOf(" ")));
textView = holder.length;
textView.setText(trip.getLength() + (trip.getLength() == 1 ? " day" : " days"));
}
#Override
public int getItemCount() {
return trips.size();
}
}

Put this code below to replace your TripAdapter code.
package com.alonkh2.finalproject;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class TripAdapter extends RecyclerView.Adapter<TripAdapter.ViewHolder> {
Context context;
private ArrayList<Trip> trips;
public class ViewHolder extends RecyclerView.ViewHolder {
// Your holder should contain a member variable
// for any view that will be set as you render a row
public TextView destination, startDate, endDate, length;
// We also create a constructor that accepts the entire item row
// and does the view lookups to find each subview
public ViewHolder(View itemView) {
// Stores the itemView in a public final member variable that can be used
// to access the context from any ViewHolder instance.
super(itemView);
destination = (TextView) itemView.findViewById(R.id.destination);
startDate = (TextView) itemView.findViewById(R.id.start_date);
// endDate = (TextView) itemView.findViewById(R.id.end_date);
length = (TextView) itemView.findViewById(R.id.trip_length);
}
}
public TripAdapter(Context context, ArrayList<Trip> trips) {
this.context = context;
this.trips = trips;
}
#NonNull
#Override
public TripAdapter.ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
// Inflate the custom layout
View contactView = inflater.inflate(R.layout.activity_listview, parent, false);
// Return a new holder instance
return new ViewHolder(contactView);
}
#Override
public void onBindViewHolder(#NonNull TripAdapter.ViewHolder holder, int position) {
Trip trip = trips.get(position);
// Set item views based on your views and data model
holder.destination.setText(trip.getDestination());
holder.startDate.setText(trip.getStrStartDate().substring(0, trip.getStrStartDate().indexOf(" ")));
// holder.endDate.setText(trip.getStrEndDate().substring(0, trip.getStrEndDate().indexOf(" ")));
holder.length.setText(trip.getLength() + (trip.getLength() == 1 ? " day" : " days"));
}
#Override
public int getItemCount() {
return trips.size();
}
}

How to add the ListView element to be referenced in the individual Activity files

The app crashes as soon as any of the list Activities are launched:
NullPointerException: Attempt to invoke virtual method 'void android.widget.ListView.setAdapter' on a null object reference
My instructor says its happening because the layouts haven't been configured correctly. Right now, the list_item is being inflated as the Activity layout. Please create a separate layout, such as activity_list and add the ListView element there to be referenced in the individual Activity files
Here's the code
MainActivity
package com.example.tourguide;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.*;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button event = (Button) findViewById(R.id.events);
Button mall = (Button) findViewById(R.id.malls);
Button resturant = (Button) findViewById(R.id.resturants);
Button university = (Button) findViewById(R.id.uinversities);
event.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent event = new Intent(MainActivity.this, events.class);
startActivity(event); }
});
mall.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent mall = new Intent(MainActivity.this, malls.class);
startActivity(mall);
}
});
resturant.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent resturant = new Intent(MainActivity.this, resturants.class);
startActivity(resturant);
}
});
university.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent university = new Intent(MainActivity.this, universities.class);
startActivity(university);
}
});
}}
WordAdapter.java
package com.example.tourguide;
import android.app.Activity;
import android.content.Context;
import android.support.annotation.LayoutRes;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;
public class WordAdapter extends ArrayAdapter<listitem> {
public WordAdapter(Activity context, ArrayList<listitem> listitems) {
super(context, 0, listitems);
}
public View getView(int position, View convertView, ViewGroup parent) {
View listItemView = convertView;
if(listItemView == null) {
listItemView = LayoutInflater.from(getContext()).inflate(
R.layout.list_item, parent, false);
}
listitem currentItem = getItem(position);
TextView name = (TextView) listItemView.findViewById(R.id.text1);
name.setText(currentItem.getName());
ImageView image = (ImageView) listItemView.findViewById(R.id.image1);
image.setImageResource(currentItem.getImage());
TextView dist = (TextView) listItemView.findViewById(R.id.text2);
dist.setText(currentItem.getDist());
TextView price = (TextView) listItemView.findViewById(R.id.text2);
price.setText(currentItem.getPrice());
return listItemView;
}
}
listitem.java
package com.example.tourguide;
import android.widget.ImageView;
public class listitem {
private String name="";
private int image;
private String dist="";
private String price="";
public listitem(String namea, int imagea, String dista, String pricea){
name = namea;
imagea = image;
dist= dista;
price=pricea;
}
/*********** Set Methods ******************/
public void setName(String name)
{
this.name = name;
}
public void setImage(int image)
{
this.image = image;
}
public void setDist(String dist)
{
this.dist = dist;
}
public void setPrice(String price)
{
this.price = price;
}
/*********** Get Methods ****************/
public String getName()
{
return this.name;
}
public int getImage()
{
return this.image;
}
public String getDist()
{
return this.dist;
}
public String getPrice()
{
return this.price;
}
}
Univerisities.java
package com.example.tourguide;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.ListView;
import java.util.ArrayList;
public class universities extends Activity {
protected void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.list_item);
ArrayList<listitem> listitemArrayList = new ArrayList<listitem>();
listitemArrayList.add(new listitem("Prince Sultan University", R.drawable.u1, "AlNarjes Dist", "$"));
listitemArrayList.add(new listitem("Princess Nourah University", R.drawable.u2, "AlNarjes Dist", "$"));
listitemArrayList.add(new listitem("King Saud University", R.drawable.u3, "AlNarjes Dist", "$"));
WordAdapter adapter = new WordAdapter(this, listitemArrayList);
ListView listView = (ListView) findViewById(R.id.list);
listView.setAdapter(adapter);
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.tourguide.MainActivity"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="29sp"
android:textColor="#3DC195"
android:textAlignment="center"
android:text="Tour Guide App" />
<TextView
android:id="#+id/text2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textColor="#6AA13F"
android:textSize="18sp"
android:text="Tour Guide App is designed to help you discover Riyadh city sightseeings including events, malls, resturants and universities.the app will be developed periodically to add more features... stay tuned" />
<Button
android:id="#+id/events"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Events"
android:onClick="onClickEvent"/>
<Button
android:id="#+id/malls"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Malls"
android:onClick="onClickMall"/>
<Button
android:id="#+id/resturants"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Resturants"
android:onClick="onClickRest"/>
<Button
android:id="#+id/uinversities"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Universities"
android:onClick="onClickUniv"/>
</LinearLayout>
activity_list.xml
<?xml version="1.0" encoding="utf-8"?>
<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:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical" android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<ImageView
android:id="#+id/image1"
android:layout_width="163dp"
android:layout_height="96dp"
android:layout_marginLeft="15dp"
android:layout_marginTop="15dp"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="68dp"
android:layout_marginTop="30dp"
android:orientation="vertical">
<TextView
android:id="#+id/text1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textColor="#DB0BA4"
android:textSize="20sp"
/>
<TextView
android:id="#+id/text2"
android:layout_width="113dp"
android:layout_height="wrap_content"
android:textColor="#456233"
android:textSize="15sp"
/>
<TextView
android:id="#+id/text3"
android:layout_width="113dp"
android:layout_height="wrap_content"
android:textColor="#C1B03D"
android:textSize="15sp"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

In the file Univerisities.java you should change your layout file to activity_list.xml.
Line
setContentView(R.layout.list_item);
Must be changed to :
setContentView(R.layout.activity_list);

Bro,
First you are trying to inflate the ListView item into you activity, which is wrong:
Change the setContentView(R.layout.list_item) to setContentView(R.layout.activity_list);
Also please check out the ViewHolder pattern for ListView's since the your adapter's getView method should be improved by that to make scrolling even more smooth:
View listItemView = convertView;
if(listItemView == null) {
listItemView = LayoutInflater.from(getContext()).inflate(
R.layout.list_item, parent, false);
}
and if no items are appearing in the list, you should also override the getItemCount on adatpterto return the size of the list.

Display Data in GridView with DataAdapter in Android

I have try the following code for displaying data from data adapter in gridview.
Following link is for GridView with DataAdapter Tutorial.
I am wanted the following output :
I have follow the tutorial and get the output as i wanted, but unfortunetly when scroll the page,
application will be closed automatically.
ERROR : "Application Failure Detected, Please Try Again"
How to resolve these problem?
code : main.xml file.
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/gridview"
android:stretchMode="columnWidth"
android:cacheColorHint="#00000000"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:numColumns="2"
android:clipChildren="true"
android:horizontalSpacing="5dip"
android:verticalSpacing="5dip" />
code : MainActivity.java file.
package com.example.gridviewdata;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.widget.GridView;
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new DataAdapter(this));
}
code : customgrid.xml file
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<TableLayout android:id="#+id/TableLayout01"
android:layout_height="wrap_content"
android:layout_width="fill_parent">
<TableRow android:id="#+id/TableRow01"
android:layout_height="wrap_content"
android:layout_width="wrap_content">
<TextView android:text="#string/hello_world"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/txtId"
android:layout_gravity="center_horizontal" />
<TextView android:text="#string/hello_world"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/txtName"
android:layout_gravity="center_horizontal" />
</TableRow>
</TableLayout>
</LinearLayout>
code : DataAdapter.java file
package com.example.gridviewdata;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
public class DataAdapter extends BaseAdapter {
Context mContext;
private String [] id = {"S001","S002","S003","S004","S005","S006","S007","S008","S009","S010","S011","S012"};
private String [] name={"Rohit","Rahul","Ravi","Amit","Arun","Anil","Kashif","Nayan","Jay","Sagar","Jairaj","Vishal"};
private LayoutInflater mInflater;
public DataAdapter(Context c)
{
mContext=c;
mInflater = LayoutInflater.from(c);
}
public int getCount()
{
return id.length;
}
public Object getItem(int position)
{
return position;
}
public long getItemId(int position)
{
return position;
}
public View getView(int position, View convertView, ViewGroup parent)
{
ViewHolder holder=null;
if(convertView==null)
{
convertView = mInflater.inflate(R.layout.customgrid,parent,false);
holder = new ViewHolder();
holder.txtId=(TextView)convertView.findViewById(R.id.txtId);
holder.txtId.setPadding(100, 10,10 , 10);
holder.txtName=(TextView)convertView.findViewById(R.id.txtName);
holder.txtName.setPadding(100, 10, 10, 10);
if(position==0)
{
convertView.setTag(holder);
}
}
else
{
holder = (ViewHolder) convertView.getTag();
}
holder.txtId.setText(id[position]);
holder.txtName.setText(name[position]);
return convertView;
}
static class ViewHolder
{
TextView txtId;
TextView txtName;
}
}
Give any solution for these problem.
if any other resource is available then give me an reference.

Solution :
In getView() method return all items, and i have setting the tag just in the first item,
when android calls again getView for position 1, i am try to get the tag from convertView,
but i didn't called setTag for convertView 1, then getTag returns a null object, and i am try to get the object txtName from a null object, and then the error occurs.
removing the if(position==0) then application work perfectly and give the scrolling.

ListView with Custom extended BaseAdapter not showing with SherlockFragment, need hints or suggestions

I am new to android programming and I seem to have come at a stand still for several days now. I am having trouble finding a solution to my problem and tried many different solutions without success. As the title suggests, my code runs successfully but the ListView does not show up on the selected Tabs. Any suggestions of tips would be helpful.
ItemGuide.Java ------------------------------------
package com.example.alzuni_project;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
import com.actionbarsherlock.app.ActionBar;
import com.actionbarsherlock.app.SherlockFragmentActivity;
public class ItemGuide extends SherlockFragmentActivity {
private ViewPager mViewPager;
private TabsAdapter mTabsAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mViewPager = new ViewPager(this);
mViewPager.setId(R.id.pager);
setContentView(mViewPager);
final ActionBar bar = getSupportActionBar();
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
bar.setDisplayShowTitleEnabled(false);
bar.setDisplayShowHomeEnabled(false);
mTabsAdapter = new TabsAdapter(this, mViewPager);
mTabsAdapter.addTab(bar.newTab().setIcon(R.drawable.leathertab_image), LeatherTab.class, null);
mTabsAdapter.addTab(bar.newTab().setIcon(R.drawable.leathertab_image), SilverTab.class, null);
}
}
LeatherTab.java --------------------------------------------------------------
package com.example.alzuni_project;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import android.widget.TextView;
import com.actionbarsherlock.app.SherlockFragment;
public class LeatherTab extends SherlockFragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.leather_fragment, container, false); //Fragment Layout inflated
TextView text = (TextView) view.findViewById(R.id.boxtest);//TextView for layout testing
text.setText("Hello");
ListView leather_listview = (ListView) view.findViewById(R.id.leather_list); // List is initialized
leather_listview.setAdapter(new LeatherAdapter(getActivity())); //Custom list adapter passes Context
return view;
}
}
LeatherAdapter.java ------------------------------------------------------
package com.example.alzuni_project;
import java.util.ArrayList;
import android.content.Context;
import android.content.res.Resources;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
class LeatherAdapter extends BaseAdapter {
ArrayList<SingleRow> list;
Context context;
public LeatherAdapter(Context c) {
context = c;
list = new ArrayList<SingleRow>();
Resources res = c.getResources();
String[] titles = res.getStringArray(R.array.leather_list_titles);
String[] descriptions = res.getStringArray(R.array.leather_list_description);
int[] images = {R.drawable.belt, R.drawable.wallet, R.drawable.coincase};
for (int i=0;i<images.length;i++) //Was originally 3
{
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 position, View convertView, 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.leather_title);
TextView description = (TextView) row.findViewById(R.id.leather_description);
ImageView image = (ImageView) row.findViewById(R.id.leather_icon);
SingleRow temp = list.get(position);
title.setText(temp.title);
description.setText(temp.description);
image.setImageResource(temp.image);
return row;//returns the rootView of single_row.xml
}
}
leatherfragment.xml ------------------------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="#+id/boxtest"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:background="#CCDDFF" />
<ListView
android:id="#+id/leather_list"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="#+id/boxtest" />
</RelativeLayout>
SingleRow.java -----------------------------------------------------
package com.example.alzuni_project;
class SingleRow {
String title;
String description;
int image;
SingleRow(String title, String description, int image) {
this.title=title;
this.description=description;
this.image=image;
}
}
single_row.xml ---------------------------------------------------
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ImageView
android:id="#+id/leather_icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:layout_marginLeft="48dp"
android:layout_marginTop="48dp"
android:contentDescription="#string/todo" />
<TextView
android:id="#+id/leather_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="#+id/leather_icon"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:background="#CCCCCC" />
<TextView
android:id="#+id/leather_description"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/leather_icon"
android:layout_alignLeft="#+id/leather_icon"
android:layout_alignParentRight="true"
android:layout_below="#+id/leather_title"
android:background="#CCDDFF" />

Your list seems empty , try this in your LeatherAdapter:
list.add(new SingleRow(titles[i],descriptions[i], images[i]));
Inside the for loop .

My Custom ListView display nothing

I am newbie in android. I want to create a custom listview arrayadapter. I have followed some tutorial but my emulator shows nothing for the Custom ListView. Can anyone help me figure out where is wrong with my code? Thanks in advance.
Here is my custom_listview_main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<ListView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/customListView" />
</LinearLayout>
This is my custom_listview_row.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"
android:gravity="center_vertical"
android:minHeight="64dp">
<!-- <ImageView
android:id="#+id/clv_imageView"
android:layout_width="32dp"
android:layout_height="32dp"
android:contentDescription="#string/empty"
android:layout_alignParentLeft="true"
android:layout_marginLeft="9dp"
android:layout_alignParentTop="true"/> -->
<TextView
android:id="#+id/clv_textView2"
android:layout_width="97dp"
android:layout_height="32dp"
android:layout_alignParentRight="true"
android:gravity="center_vertical"
android:text="#string/tv_definition"
android:textIsSelectable="true" />
<TextView
android:id="#+id/clv_textView"
android:layout_width="97dp"
android:layout_height="32dp"
android:layout_alignParentLeft="true"
android:gravity="center_vertical"
android:text="#string/tv_word"
android:textIsSelectable="true" />
</RelativeLayout>
Here is my MyPerformanceArrayAdapter.java
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
public class MyPerformanceArrayAdapter extends ArrayAdapter<DefinitionObject>{
private List<DefinitionObject> entries;
private Activity activity;
public MyPerformanceArrayAdapter(Activity a, int textViewResourceId, List<DefinitionObject> entries) {
super(a, textViewResourceId, entries);
this.entries = entries;
this.activity = a;
}
public static class ViewHolder{
public TextView item1;
public TextView item2;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View v = convertView;
ViewHolder holder;
if (v == null) {
LayoutInflater vi =
(LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = vi.inflate(R.layout.custom_listview_row, null);
holder = new ViewHolder();
holder.item1 = (TextView) v.findViewById(R.id.clv_textView);
holder.item2 = (TextView) v.findViewById(R.id.clv_textView2);
v.setTag(holder);
}
else
holder=(ViewHolder)v.getTag();
final DefinitionObject custom = entries.get(position);
if (custom != null) {
holder.item1.setText(custom.getWord());
holder.item2.setText(custom.getFav());
}
return v;
}
}
and lastly, this is my Activity named TempCLV.java
package com.example.myidictionary;
import java.util.List;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ListView;
public class TempCLV extends Activity {
private MySQLiteDefinitionHelper db;
String tblName = "";
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.custom_listview_main);
Intent msjIntent = getIntent();
tblName = msjIntent.getStringExtra(WordDefinitionHomeActivity.TABLENAME2);
}
public void refresh()
{
db = new MySQLiteDefinitionHelper(this);
final List<DefinitionObject> values = db.getAllWords(tblName);
ListView mylist = (ListView)findViewById(R.id.customListView);
MyPerformanceArrayAdapter adapter = new MyPerformanceArrayAdapter(this, R.id.customListView, values);
mylist.setAdapter(adapter);
}
}

You need to call refresh in onCreate since you are setting the adapter to list view there.
Make sure your values has some data
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.custom_listview_main);
Intent msjIntent = getIntent();
tblName = msjIntent.getStringExtra(WordDefinitionHomeActivity.TABLENAME2);
refresh();
}
Also you can move the inflater initialization to the constructor of adapter class. No need to initialize in getView
LayoutInflater vi;
public MyPerformanceArrayAdapter(Activity a, int textViewResourceId,List<DefinitionObject> entries) {
super(a, textViewResourceId, entries);
this.entries = entries;
vi =(LayoutInflater)a.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

Please call refresh method at least for first time to set the the adapter in your MainActivity' onCreate method..