Android ExpandableListActivity

======MainActivity.java=====================================

package com.zys.myexpandablelistactivity;

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

import android.os.Bundle;
import android.app.Activity;
import android.app.ExpandableListActivity;
import android.view.Menu;
import android.widget.SimpleExpandableListAdapter;

public class MainActivity extends ExpandableListActivity {

@Override
protected 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);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

}

========activity_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="match_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"
>

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

<TextView android:id="@+id/groupTo"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
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>