ExpandableListView

>extends ListView

>This differs from the ListView by allowing two levels: groups which can individually be expanded to show its children. The items come from the ExpandableListAdapter associated with this view.

>Following is an demo application: Click Here to download source code

Main Activity

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import android.app.Activity;

import android.os.Bundle;

import android.view.View;

import android.widget.ExpandableListView;

import android.widget.ExpandableListView.OnChildClickListener;

import android.widget.Toast;

public class MainActivity extends Activity {

ExpandableListAdapter expandableListAdapter;

ExpandableListView expandableListView;

List<String> parentListHeader;

HashMap<String, List<String>> childListData;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main_layout);

initializeDisplayElements();

prepareExpandableListData();

expandableListAdapter = new ExpandableListAdapter(this,

parentListHeader, childListData);

expandableListView.setAdapter(expandableListAdapter);

expandableListView.setOnChildClickListener(new OnChildClickListener() {

@Override

public boolean onChildClick(ExpandableListView parent, View v,

int groupPosition, int childPosition, long id) {

Toast.makeText(

getApplicationContext(),

parentListHeader.get(groupPosition)

+ " : "

+ childListData.get(

parentListHeader.get(groupPosition))

.get(childPosition), Toast.LENGTH_SHORT)

.show();

return false;

}

});

}

/**

* This method is used to prepare the expandable list data parent and

* corresponding child items.

*/

private void prepareExpandableListData() {

parentListHeader = new ArrayList<String>();

childListData = new HashMap<String, List<String>>();

// adding parent data

parentListHeader.add("Micromax");

parentListHeader.add("Moto");

parentListHeader.add("Samsung");

// adding child data

List<String> micromax = new ArrayList<String>();

micromax.add("micromax Canvas Nitro");

micromax.add("micromax Canvas Knight");

micromax.add("micromax gold");

List<String> moto = new ArrayList<String>();

moto.add("moto-G");

moto.add("moto-E");

moto.add("moto-G2");

List<String> samsung = new ArrayList<String>();

samsung.add("samsung grand");

samsung.add("samsung Note 2");

samsung.add("samsung Galaxy");

childListData.put(parentListHeader.get(0), micromax);

childListData.put(parentListHeader.get(1), moto);

childListData.put(parentListHeader.get(2), samsung);

}

/**

* This method is used to initialize display elements present on layout

*/

private void initializeDisplayElements() {

expandableListView = (ExpandableListView) findViewById(R.id.expandableListView1);

}

}