package com.example.mars_2300_expandablelist;

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

import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.ActionBar;
import android.support.v4.app.Fragment;
import android.app.ExpandableListActivity;
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.SimpleExpandableListAdapter;
import android.os.Build;

public class MainActivity extends ExpandableListActivity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_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);
    }
}

<?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>

<?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>

<?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>