expandablelistView

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ExpandableListView
        android:id="@+id/expand_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;

public class ExpadableActivity extends Activity {

	private ExpandableListView eListView;
	public String[] groupStrings = { "group1", "group2", "group3", "group4" };
	public String[][] childStrings = { { "child1-1", "child1-2", "child1-3", "child1-4" }, { "child2-1", "child2-2", "child2-3", "child2-4" }, { "child3-1", "child3-2", "child3-3", "child3-4" }, { "child4-1", "child4-2", "child4-3", "child4-4" } };

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_expadable);
		eListView = (ExpandableListView) findViewById(R.id.expand_list);
		eListView.setAdapter(new MyAdapter());
	}

	private class MyAdapter extends BaseExpandableListAdapter {

		@Override
		public int getGroupCount() {
			return groupStrings.length;
		}

		@Override
		public int getChildrenCount(int groupPosition) {
			return childStrings[groupPosition].length;
		}

		@Override
		public Object getGroup(int groupPosition) {
			return groupStrings[groupPosition];
		}

		@Override
		public Object getChild(int groupPosition, int childPosition) {
			return childStrings[groupPosition][childPosition];
		}

		@Override
		public long getGroupId(int groupPosition) {
			return groupPosition;
		}

		@Override
		public long getChildId(int groupPosition, int childPosition) {
			return childPosition;
		}

		@Override
		public boolean hasStableIds() {
			return true;
		}

		@Override
		public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
			GroupViewHolder groupViewHolder;
			if (convertView == null) {
				convertView = LayoutInflater.from(ExpadableActivity.this).inflate(R.layout.ly_expandablelist, parent, false);
				groupViewHolder = new GroupViewHolder();
				groupViewHolder.tvTitle = (TextView) convertView.findViewById(R.id.label_expand_group);
				convertView.setTag(groupViewHolder);
			} else {
				groupViewHolder = (GroupViewHolder) convertView.getTag();
			}
			groupViewHolder.tvTitle.setText(groupStrings[groupPosition]);
			return convertView;
		}

		@Override
		public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
			ChildViewHolder childViewHolder;
			if (convertView == null) {
				convertView = LayoutInflater.from(ExpadableActivity.this).inflate(R.layout.ly_expandablelistchild, parent, false);
				childViewHolder = new ChildViewHolder();
				childViewHolder.tvTitle = (TextView) convertView.findViewById(R.id.label_expand_child);
				convertView.setTag(childViewHolder);
			} else {
				childViewHolder = (ChildViewHolder) convertView.getTag();
			}
			childViewHolder.tvTitle.setText(childStrings[groupPosition][childPosition]);
			return convertView;
		}

		@Override
		public boolean isChildSelectable(int groupPosition, int childPosition) {
			return true;
		}

	}

	static class GroupViewHolder {
		TextView tvTitle;
	}

	static class ChildViewHolder {
		TextView tvTitle;
	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/label_expand_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:background="@android:color/holo_blue_light"
        android:paddingLeft="20dp"
        android:textColor="@android:color/white"
        android:textSize="20sp" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/label_expand_child"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:background="@android:color/holo_blue_light"
        android:paddingLeft="20dp"
        android:textColor="@android:color/background_dark"
        android:textSize="20sp" />

</LinearLayout>