ListView in Android
ListView
ArrayAdapter
Init
ListView listView = (ListView) findViewById(R.id.lvItems);
ArrayAdapter<String> itemsAdapter =
new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, items);
listView.setAdapter(itemsAdapter);
Display in getView
public class UsersAdapter extends ArrayAdapter<User> {
public UsersAdapter(Context context, ArrayList<User> users) {
super(context, 0, users);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
User user = getItem(position);
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_user, parent, false);
}
// Lookup view for data population
TextView tvName = (TextView) convertView.findViewById(R.id.tvName);
TextView tvHome = (TextView) convertView.findViewById(R.id.tvHome);
// Populate the data into the template view using the data object
tvName.setText(user.name);
tvHome.setText(user.hometown);
convertView.setTag(User);
// Return the completed view to render on screen
return convertView;
}
}
Deal with click
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if (!waitForResponse) {
final User user = (User) parent.getItemAtPosition(position);
}
}
});
Improving Performance with the ViewHolder Pattern
public class UsersAdapter extends ArrayAdapter<User> {
// View lookup cache
private static class ViewHolder {
TextView name;
TextView home;
}
public UsersAdapter(Context context, ArrayList<User> users) {
super(context, R.layout.item_user, users);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
User user = 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) {
// If there's no view to re-use, inflate a brand new view for row
viewHolder = new ViewHolder();
LayoutInflater inflater = LayoutInflater.from(getContext());
convertView = inflater.inflate(R.layout.item_user, parent, false);
viewHolder.name = (TextView) convertView.findViewById(R.id.tvName);
viewHolder.home = (TextView) convertView.findViewById(R.id.tvHome);
// Cache the viewHolder object inside the fresh view
convertView.setTag(viewHolder);
} else {
// View is being recycled, retrieve the viewHolder object from tag
viewHolder = (ViewHolder) convertView.getTag();
}
// Populate the data from the data object via the viewHolder object
// into the template view.
viewHolder.name.setText(user.name);
viewHolder.home.setText(user.hometown);
// Return the completed view to render on screen
return convertView;
}
}