控件：ExpandableListView 树型组件

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/elistview"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

MyExpandableListAdapter.java   (适配器)

package org.lxh.demo;

import android.content.Context;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;
// 继承BaseExpandableListAdapter并覆写类中的抽象方法
public class MyExpandableListAdapter extends BaseExpandableListAdapter {
    // 组名称
    public String[] groups = { "我的好友", "家人", "同事", "黑名单" };    
    // 定义组项
    public String[][] children = {
            { "董鸣楠", "王月清", "周艳军" }, 
            { "父亲", "母亲" }, { "刘宏伟", "李祺", "刘媛" },
            { "票贩子", "造假商" } };        
    // 保存上下文对象
    private Context context = null;        
    // 构造方法接收
    public MyExpandableListAdapter(Context context) {                
        this.context = context;
    }
    @Override   // 取得指定的子项
    public Object getChild(int groupPosition, int childPosition) {    
        return this.children[groupPosition][childPosition];
    }

    @Override   // 取得子项ID
    public long getChildId(int groupPosition, int childPosition) {    
        return childPosition;
    }
    
    // 自定义方法，建立文本
    public TextView buildTextView() {        
        // 指定布局参数
        AbsListView.LayoutParams param = new AbsListView.LayoutParams(
                ViewGroup.LayoutParams.FILL_PARENT, 35);
        // 创建TextView
        TextView textView = new TextView(this.context);                
        textView.setLayoutParams(param);    // 设置布局参数
        textView.setTextSize(15.0f);        // 设置文字大小
        textView.setGravity(Gravity.LEFT);    // 左对齐
        textView.setPadding(40, 8, 3, 3);    // 间距
        return textView;                    // 返回组件

    }

    @Override   // 返回子项组件
    public View getChildView(int groupPosition, int childPosition,
            boolean isLastChild, View convertView, ViewGroup parent) {
        // 创建TextView
        TextView textView = buildTextView();    
        // 设置显示文字
        textView.setText(getChild(groupPosition,childPosition).toString());                            
        return textView;

    }

    @Override   // 取得子项个数
    public int getChildrenCount(int groupPosition) {    
        // 取得子项个数
        return this.children[groupPosition].length;                    
    }

    @Override   // 取得组对象
    public Object getGroup(int groupPosition) {                        
        return this.groups[groupPosition];
    }

    @Override   // 取得组个数
    public int getGroupCount() {                                    
        return this.groups.length;
    }

    @Override   // 取得组ID
    public long getGroupId(int groupPosition) {                        
        return groupPosition;
    }

    @Override    // 取得组显示组件
    public View getGroupView(int groupPosition, boolean isExpanded,
            View convertView, ViewGroup parent) {        
        // 建立组件
        TextView textView = buildTextView();
        // 设置文字
        textView.setText(this.getGroup(groupPosition).toString());    
        return textView;
    }

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

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

}

MyExpandableListViewDemo.java

package org.lxh.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.View;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.ExpandableListView.OnChildClickListener;
import android.widget.ExpandableListView.OnGroupClickListener;
import android.widget.ExpandableListView.OnGroupCollapseListener;
import android.widget.ExpandableListView.OnGroupExpandListener;
import android.widget.Toast;

public class MyExpandableListViewDemo extends Activity {
    // 定义树型组件
    private ExpandableListView elistview = null;    
    // 定义适配器对象
    private ExpandableListAdapter adapter = null;            

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // 默认布局管理器
        super.setContentView(R.layout.main);     
        // 取得组件
        this.elistview = (ExpandableListView) super.findViewById(R.id.elistview);     
        // 实例化适配器
        this.adapter = new MyExpandableListAdapter(this);    
        // 设置适配器
        this.elistview.setAdapter(this.adapter);    
        // 注册上下文菜单
        super.registerForContextMenu(this.elistview);         
        // 设置子项单击事件
        this.elistview.setOnChildClickListener(new OnChildClickListenerImpl());            
        // 设置组项单击事件
        this.elistview.setOnGroupClickListener(new OnGroupClickListenerImpl());            
        // 关闭分组事件
        this.elistview.setOnGroupCollapseListener(new OnGroupCollapseListenerImpl());         
        // 展开分组事件
        this.elistview.setOnGroupExpandListener(new OnGroupExpandListenerImpl());             
    }

    private class OnChildClickListenerImpl implements OnChildClickListener {
        @Override
        public boolean onChildClick(ExpandableListView parent, View v,
                int groupPosition, int childPosition, long id) {
            // 显示提示框
            Toast.makeText(
                    MyExpandableListViewDemo.this,
                    "子选项被选中，groupPosition = " + groupPosition
                            + "，childPosition = " + childPosition,
                    Toast.LENGTH_SHORT).show();                
            return false;
        }
        
    }

    private class OnGroupClickListenerImpl implements OnGroupClickListener {

        @Override
        public boolean onGroupClick(ExpandableListView parent, View v,
                int groupPosition, long id) {
            // 显示提示框
            Toast.makeText(MyExpandableListViewDemo.this,
                    "分组被选中，groupPosition = " + groupPosition,
                    Toast.LENGTH_SHORT).show();                
            return false;
        }

    }

    private class OnGroupCollapseListenerImpl implements
            OnGroupCollapseListener {

        @Override
        public void onGroupCollapse(int groupPosition) {
            // 显示提示框
            Toast.makeText(MyExpandableListViewDemo.this,
                    "关闭分组，groupPosition = " + groupPosition, 
                    Toast.LENGTH_SHORT).show();                                
        }

    }

    private class OnGroupExpandListenerImpl implements OnGroupExpandListener {

        @Override
        public void onGroupExpand(int groupPosition) {
            // 显示提示框
            Toast.makeText(MyExpandableListViewDemo.this,
                    "打开分组，groupPosition = " + groupPosition, 
                    Toast.LENGTH_SHORT).show();                                
        }
    }
    @Override
    public void onCreateContextMenu(ContextMenu menu, View view,
            ContextMenuInfo menuInfo) {
        super.onCreateContextMenu(menu, view, menuInfo);
        ExpandableListView.ExpandableListContextMenuInfo info = 
            (ExpandableListView.ExpandableListContextMenuInfo) menuInfo;
        // 取得操作的菜单项
        int type = ExpandableListView.getPackedPositionType(info.packedPosition); 
        // 取得菜单项所在的菜单组
        int group = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
        // 取得子菜单项的索引
        int child = ExpandableListView.getPackedPositionChild(info.packedPosition); 
        // 显示提示框
        Toast.makeText(MyExpandableListViewDemo.this,
                "type = " + type + "，group = " + group + "，child = " + child,
                Toast.LENGTH_SHORT).show();                    
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="org.lxh.demo"
      android:versionCode="1"
      android:versionName="1.0">
    <uses-sdk android:minSdkVersion="5" />

    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".MyExpandableListViewDemo"
                  android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    </application>
</manifest>