Hey guys i have a ListActivity... a very simple at that... and it keeps throwing NullPointer Exception though i have done it exactly as the Sample List7 except that i have used the Layout inflater... below is the code... Can u plz comment the error i have done here??
import java.util.Vector;
import android.app.Activity;
import android.app.ListActivity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemSelectedListener;
public class CustomList extends ListActivity implements OnItemSelectedListener{
Vector<String> VTitle;
Vector<String> VDescription;
TextView display;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
VTitle.addElement("First Title");
VTitle.addElement("Second Title");
VTitle.addElement("Third Title");
VTitle.addElement("Fourth Title");
VDescription.addElement("1 Description");
VDescription.addElement("2 Description");
VDescription.addElement("3 Description");
VDescription.addElement("4 Description");
display = (TextView)findViewById(R.id.display);
setListAdapter(new CustomAdapter(this));
}
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
// TODO Auto-generated method stub
display.setText(VTitle.elementAt(position));
}
class CustomAdapter extends BaseAdapter {
protected Activity mContext;
public CustomAdapter(Activity context) {
mContext = context;
// TODO Auto-generated constructor stub
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return VTitle.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View row = convertView;
if(row==null) {
LayoutInflater inflater = mContext.getLayoutInflater();
row = inflater.inflate(R.layout.row,null);
}
TextView title = (TextView)row.findViewById(R.id.title);
title.setText(VTitle.elementAt(position));
TextView description = (TextView)row.findViewById(R.id.description);
description.setText(VDescription.elementAt(position));
ImageView image = (ImageView)row.findViewById(R.id.image);
switch(position){
case 0:
image.setImageResource(R.drawable.check);
break;
case 1:
image.setImageResource(R.drawable.dos);
break;
case 2:
image.setImageResource(R.drawable.smily);
break;
case 3:
image.setImageResource(R.drawable.wrong);
break;
}
return(row);
}
}
@Override
public void onItemSelected(AdapterView parent, View v, int position, long id) {
// TODO Auto-generated method stub
display.setText(VTitle.elementAt(position));
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
}
And the xmls are like this....
"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" >
<TextView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id = "@+id/display"
android:text="something"
/>
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:drawSelectorOnTop="false"
android:layout_height="0px">
</ListView>
</LinearLayout>
"row.xml"
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<ImageView
android:id="@+id/image"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</ImageView>
<TextView
android:text="Title"
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</TextView>
<TextView
android:text="description"
android:id="@+id/description"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</TextView>
</LinearLayout>