Can any one provide me two_line_list_item example?
I have yet to find an example that actually uses the built-in layout, android.R.layout.two_line_list_item
and a ListView
insted of ListActivity
. So here goes.
If you're in a hurry, the TwoLineArrayAdapter.getView()
override below is the important part of using the default two_line_list_item
layout.
You have a class that defines your list items. I'll assume you have an array of these.
public class Employee {
public String name;
public String title;
}
This abstract class can be reused, and makes defining a two-line ListView
much easier later. You can supply your own layout, but the two argument constructor uses the built-in two_line_list_item
layout. The only requirement for custom list item layouts is that they must use @android:id/text1
and @android:id/text2
to identify their TextView
children, just as two_line_list_item
does.
public abstract class TwoLineArrayAdapter<T> extends ArrayAdapter<T> {
private int mListItemLayoutResId;
public TwoLineArrayAdapter(Context context, T[] ts) {
this(context, android.R.layout.two_line_list_item, ts);
}
public TwoLineArrayAdapter(
Context context,
int listItemLayoutResourceId,
T[] ts) {
super(context, listItemLayoutResourceId, ts);
mListItemLayoutResId = listItemLayoutResourceId;
}
@Override
public android.view.View getView(
int position,
View convertView,
ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater)getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View listItemView = convertView;
if (null == convertView) {
listItemView = inflater.inflate(
mListItemLayoutResId,
parent,
false);
}
// The ListItemLayout must use the standard text item IDs.
TextView lineOneView = (TextView)listItemView.findViewById(
android.R.id.text1);
TextView lineTwoView = (TextView)listItemView.findViewById(
android.R.id.text2);
T t = (T)getItem(position);
lineOneView.setText(lineOneText(t));
lineTwoView.setText(lineTwoText(t));
return listItemView;
}
public abstract String lineOneText(T t);
public abstract String lineTwoText(T t);
}
Finally, here's the code you write specific to your Employee class so that it'll render in your ListView
.
public class EmployeeArrayAdapter extends TwoLineArrayAdapter<Employee> {
public EmployeeArrayAdapter(Context context, Employee[] employees) {
super(context, employees);
}
@Override
public String lineOneText(Employee e) {
return e.name;
}
@Override
public String lineTwoText(Employee e) {
return e.title;
}
}
In your Activity's onCreate()
method, you'll have code that looks like this:
employees = new Employee[...];
//...populate the employee array...
employeeLV = (ListView)findViewById(R.id.employee_list);
employeeLV.setAdapter(new EmployeeArrayAdapter(this, employees);