android 控件 ExpandableListView 二级listview

实现ExpandableAdapter的三种方式 
一是扩展BaseExpandableListAdpter实现ExpandableAdapter。
二是使用SimpleExpandableListAdpater将两个List集合包装成ExpandableAdapter
三是使用simpleCursorTreeAdapter将Cursor中的数据包装成SimpleCuroTreeAdapter
 
一般适用于ExpandableListView的Adapter都要继承BaseExpandableListAdapter这个类，并且必须重载getGroupView和getChildView这两个最为重要的方法。
当扩展BaseExpandableListAdapter时，关键是实现如下四个方法：
1.public abstract ViewgetChildView (int groupPosition, intchildPosition, boolean isLastChild, ViewconvertView, ViewGroup parent)
取得显示给定分组给定子位置的数据用的视图.


2.public abstract intgetChildrenCount (int groupPosition)
取得指定分组的子元素数.


3.public abstract ViewgetGroupView (int groupPosition, booleanisExpanded, View convertView, ViewGroupparent)
取得用于显示给定分组的视图.这个方法仅返回分组的视图对象，要想获取子元素的视图对象，就需要调用getChildView(int, int, boolean, View, ViewGroup).


4.public abstract intgetGroupCount ()
取得分组数.


示例：

import android.os.Bundle;  
import android.app.Activity;  
import android.graphics.Color;  
import android.view.Gravity;  
import android.view.Menu;  
import android.view.View;  
import android.view.ViewGroup;  
import android.widget.AbsListView;  
import android.widget.BaseExpandableListAdapter;  
import android.widget.ExpandableListAdapter;  
import android.widget.ExpandableListView;  
import android.widget.ExpandableListView.OnChildClickListener;  
import android.widget.ImageView;  
import android.widget.LinearLayout;  
import android.widget.TextView;  
import android.widget.Toast;  
/** 
 * Describe:
 
 * 可扩展的ListView
 
 * 本实例主要通过扩展BaseExpandableListAdapter来实现ExpandableListAdapter
 
 * 并通过ExpandableListAdapter为ExpandableListView设置数据适配器
 
 * 另外，本实例为ExpandableListView的子列表单击事件设置监听器*  
 * @author jph 
 * Date:2014.07.14 
 * */  
public class ExpandableListViewDemo extends Activity {  
	ExpandableListView list;  
	@Override  
	protected void onCreate(Bundle savedInstanceState) {  
		super.onCreate(savedInstanceState);  
		setContentView(R.layout.activity_expandable_list_view);  
		list=(ExpandableListView)findViewById(R.id.list);  
		//创建一个BaseExpandableListAdapter对象  
		final ExpandableListAdapter adapter=new BaseExpandableListAdapter() {  
			//设置组视图的图片  
			int[] logos = new int[] { R.drawable.js, R.drawable.mfzw,R.drawable.yczw};  
			//设置组视图的显示文字  
			private String[] category = new String[] { "僵尸  ", "魔法植物", "远程植物" };  
			//子视图显示文字  
			private String[][] subcategory = new String[][] {  
					{"旗帜僵尸", "铠甲僵尸", "书生见识", "铁桶僵尸", "尸娃僵尸","舞蹈僵尸" },  
					{ "黄金蘑菇", "贪睡蘑菇", "大头蘑菇", "诱惑植物", "多嘴蘑菇","七彩蘑菇" },  
					{ "满天星", "风车植物", "带刺植物", "贪睡植物","双子植物","胆怯蘑菇" }  
  
			};  
			//子视图图片  
			public int[][] sublogos = new int[][] {  
					{ R.drawable.js_1,R.drawable.js_2,R.drawable.js_3,  
					  R.drawable.js_4,R.drawable.js_5,R.drawable.js_6},  
					{ R.drawable.mfzw_1,R.drawable.mfzw_2,R.drawable.mfzw_3,  
					  R.drawable.mfzw_4,R.drawable.mfzw_5,R.drawable.mfzw_6},  
					{ R.drawable.yczw_1,R.drawable.yczw_2,R.drawable.yczw_3,  
					  R.drawable.yczw_4,R.drawable.yczw_5,R.drawable.yczw_6 } };  
			//定义一个显示文字信息的方法  
			TextView getTextView(){
				AbsListView.LayoutParams lp=new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,64);  
				TextView textView=new TextView(ExpandableListViewDemo.this);  
				//设置 textView控件的布局 
				textView.setLayoutParams(lp); 
				//设置该textView中的内容相对于textView的位置  
				textView.setGravity(Gravity.CENTER_VERTICAL);  
				//设置txtView的内边距
				textView.setPadding(36, 0, 0, 0);  
				//设置文本颜色  
				textView.setTextColor(Color.BLACK); 
				return textView;
			}  
			@Override  
			public boolean isChildSelectable(int groupPosition, int childPosition) {  
				// TODO Auto-generated method stub  
				return true;  
			}  
			  
			@Override  
			public boolean hasStableIds() {  
				// TODO Auto-generated method stub  
				return true;  
			}  
			//取得用于显示给定分组的视图. 这个方法仅返回分组的视图对象  
			@Override  
			public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {  
				// TODO Auto-generated method stub  
				//定义一个LinearLayout用于存放ImageView、TextView  
				LinearLayout ll=new LinearLayout(ExpandableListViewDemo.this);  
				//设置子控件的显示方式为水平  
				ll.setOrientation(0);  
				//定义一个ImageView用于显示列表图片  
				ImageView logo=new ImageView(ExpandableListViewDemo.this);  
				logo.setPadding(50, 0, 0, 0);  
				//设置logo的大小(50（padding）+46=96)  
				AbsListView.LayoutParams lparParams=new AbsListView.LayoutParams(96,46);  
				logo.setLayoutParams(lparParams);  
				logo.setImageResource(logos[groupPosition]);  
				ll.addView(logo);  
				TextView textView=getTextView();  
				textView.setTextSize(20);  
				textView.setText(category[groupPosition]);  
				ll.addView(textView);  
				return ll;  
			}  
			//取得指定分组的ID.该组ID必须在组中是唯一的.必须不同于其他所有ID（分组及子项目的ID）.  
			@Override  
			public long getGroupId(int groupPosition) {  
				// TODO Auto-generated method stub  
				return groupPosition;  
			}  
			//取得分组数  
			@Override  
			public int getGroupCount() {  
				// TODO Auto-generated method stub  
				return category.length;  
			}  
			//取得与给定分组关联的数据  
			@Override  
			public Object getGroup(int groupPosition) {  
				// TODO Auto-generated method stub  
				return category[groupPosition];  
			}  
			//取得指定分组的子元素数.  
			@Override  
			public int getChildrenCount(int groupPosition) {  
				// TODO Auto-generated method stub  
				return subcategory[groupPosition].length;  
			}  
			//取得显示给定分组给定子位置的数据用的视图  
			@Override  
			public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {  
				// TODO Auto-generated method stub  
				//定义一个LinearLayout用于存放ImageView、TextView  
				LinearLayout ll=new LinearLayout(ExpandableListViewDemo.this);  
				//设置子控件的显示方式为水平  
				ll.setOrientation(0);  
				//定义一个ImageView用于显示列表图片  
				ImageView logo=new ImageView(ExpandableListViewDemo.this);  
				logo.setPadding(0, 0, 0, 0);  
				//设置logo的大小  
				LinearLayout.LayoutParams lp=new LinearLayout.LayoutParams(40, 40);  
				logo.setLayoutParams(lp);  
				logo.setImageResource(sublogos[groupPosition][childPosition]);  
				ll.addView(logo);  
				TextView textView=getTextView();  
				textView.setText(subcategory[groupPosition][childPosition]);  
				ll.addView(textView);  
				return ll;  
			}  
			//取得给定分组中给定子视图的ID. 该组ID必须在组中是唯一的.必须不同于其他所有ID（分组及子项目的ID）.  
			@Override  
			public long getChildId(int groupPosition, int childPosition) {  
				// TODO Auto-generated method stub  
				return childPosition;  
			}  
			  
			@Override  
			public Object getChild(int groupPosition, int childPosition) {  
				// TODO Auto-generated method stub  
				return subcategory[groupPosition][childPosition];  
			}  
		};  
		list.setAdapter(adapter);         
		//为ExpandableListView的子列表单击事件设置监听器  
		list.setOnChildClickListener(new OnChildClickListener() {             
			@Override  
			public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {  
				// TODO Auto-generated method stub  
				Toast.makeText(ExpandableListViewDemo.this, "你单击了："  
						+adapter.getChild(groupPosition, childPosition), Toast.LENGTH_LONG).show();  
				return true;  
			}  
		});  
	}  
  
	@Override  
	public boolean onCreateOptionsMenu(Menu menu) {  
		// Inflate the menu; this adds items to the action bar if it is present.  
		getMenuInflater().inflate(R.menu.expandable_list_view, menu);  
		return true;  
	}  
  
}