ExpandableListActivity

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"
         >

     <ExpandableListView android:id="@id/android:list"
               android:layout_width="fill_parent"
               android:layout_height="fill_parent"
               android:drawSelectorOnTop="false"/>

     <TextView android:id="@id/android:empty"
               android:layout_width="fill_parent"
               android:layout_height="fill_parent"
               android:text="No data"/>
 </LinearLayout>

group.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:id="@+id/groupTo"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent"
		android:paddingLeft="60px"
		android:paddingTop="10px"
		android:paddingBottom="10px"
		android:textSize="26sp"
		android:text="No data" />
</LinearLayout>

child.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:id="@+id/childTo"
		android:layout_width="fill_parent"
		android:layout_height="fill_parent"
		android:paddingLeft="50px"
		android:paddingTop="5px"
		android:paddingBottom="5px"
		android:textSize="20sp"
		android:text="No data" />
</LinearLayout>

MainActivity.java:

package mars.expandable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.widget.SimpleExpandableListAdapter;

/*
 * 创建一个Activity，继承ExpandableListAcitivty
 */
public class MainActivity extends ExpandableListActivity {
	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		//定义一个List，该List对象为一级条目提供数据
		List<Map<String, String>> groups = new ArrayList<Map<String, String>>();
		Map<String, String> group1 = new HashMap<String, String>();
		group1.put("group", "group1");
		Map<String, String> group2 = new HashMap<String, String>();
		group2.put("group", "group2");
		groups.add(group1);
		groups.add(group2);

		//定义一个List，该List对象为第一个一级条目提供二级条目的数据
		List<Map<String, String>> child1 = new ArrayList<Map<String, String>>();
		Map<String, String> child1Data1 = new HashMap<String, String>();
		child1Data1.put("child", "child1Data1");
		child1.add(child1Data1);
		Map<String,String> child1Data2 = new HashMap<String,String>();
		child1Data2.put("child", "child1Data2");
		child1.add(child1Data2);

		//定义一个List,该List对象为第二个一级条目提供二级条目的数据
		List<Map<String, String>> child2 = new ArrayList<Map<String, String>>();
		Map<String, String> child2Data = new HashMap<String, String>();
		child2Data.put("child", "child2Data");
		child2.add(child2Data);

		//定义一个List，该List对象用来存储所有的二级条目的数据
		List<List<Map<String, String>>> childs = new ArrayList<List<Map<String, String>>>();
		childs.add(child1);
		childs.add(child2);

		//生成一个SimpleExpandableListAdapter对象
		//1.context
		//2.一级条目的数据
		//3.用来设置一级条目样式的布局文件
		//4.指定一级条目数据的key
		//5.指定一级条目数据显示控件的id
		//6.指定二级条目的数据
		//7.用来设置二级条目样式的布局文件
		//8.指定二级条目数据的key
		//9.指定二级条目数据显示控件的id
		SimpleExpandableListAdapter sela = new SimpleExpandableListAdapter(
				this, groups, R.layout.group, new String[] { "group" },
				new int[] { R.id.groupTo }, childs, R.layout.child,
				new String[] { "child" }, new int[] { R.id.childTo });
		//将SimpleExpandableListAdapter对象设置给当前的ExpandableListActivity
		setListAdapter(sela);
	}
}

效果如图：