ExpandableListView是对ListView的扩展，实现了当点击列表项时弹出下一层的列表项

同时它必须要通过相对应的适配器来实现数据的绑定

1、首先在布局文件中创建好组件

<ExpandableListView
	    android:id="@+id/extendview" 
	    android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/myspinner"
	    >
	    
	</ExpandableListView>

第一层

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <ImageView 
        android:id="@+id/groupimage"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
	<TextView 
	    android:id="@+id/grouptext"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:layout_toRightOf="@id/groupimage"
	    />
</RelativeLayout>

第二层

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <ImageView 
        android:id="@+id/childimage"
        android:layout_width="40dp"
        android:layout_height="40dp"
        />
	<TextView 
	    android:id="@+id/childtext"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    android:layout_toRightOf="@id/childimage"
	    />
</RelativeLayout>

界面创建好之后，接下来通过java代码来实现数据绑定

2、数据绑定

自定义一个组件组类，用来封装需要显示在ExpandableListView中的组件

//自定义组件类
    public class MyView{
    	private ImageView imageView;
    	private TextView textView;
    }

定义一个方法用来封装向ExpandableListView的过程

//BaseExpandableListAdapter适配器向ExpandableListView填充数据，实现点击弹出下拉
    public void extendListView(){
    	//定义第一层的数据
    	final String[] textarr={"图片1","图片2","图片3","图片4"};//需要在textView中显示的数据
    	final int[] imgarr={R.drawable.iphone_we_flash,R.drawable.iphone_we_front,R.drawable.leica_active,R.drawable.leica_off};//需要显示的图片
    	//定义第二层数据
    	final String[][] childtextarr={{"图片1","图片2","图片3","图片4"},{"图片1","图片2","图片3","图片4"},{"图片1","图片2","图片3","图片4"},{"图片1","图片2","图片3","图片4"}};
    	final int[][] childimgarr={{R.drawable.iphone_we_flash,R.drawable.iphone_we_front,R.drawable.leica_active,R.drawable.leica_off},
    			{R.drawable.iphone_we_flash,R.drawable.iphone_we_front,R.drawable.leica_active,R.drawable.leica_off},
    			{R.drawable.iphone_we_flash,R.drawable.iphone_we_front,R.drawable.leica_active,R.drawable.leica_off},
    			{R.drawable.iphone_we_flash,R.drawable.iphone_we_front,R.drawable.leica_active,R.drawable.leica_off}
    			};
    	
    	//以匿名内部类的方式来获得BaseExpandableListAdapter适配器的对象
    	BaseExpandableListAdapter bAdapter=new BaseExpandableListAdapter() {
			
			@Override
			public boolean isChildSelectable(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				return false;
			}
			
			@Override
			public boolean hasStableIds() {
				// TODO Auto-generated method stub
				return false;
			}
			//返回一个第一层的组件
			@Override
			public View getGroupView(int groupPosition, boolean isExpanded,
					View convertView, ViewGroup parent) {
				//创建一个自定义组件容器对象
				MyView myView=null;
				if(convertView==null){
					//将组件的XML布局文件转换为View 组件
					convertView=LayoutInflater.from(MainActivity.this).inflate(R.layout.group_view, null);
					myView=new MyView();
					myView.imageView=(ImageView)convertView.findViewById(R.id.groupimage);//获得转换得View的组件
					myView.textView=(TextView)convertView.findViewById(R.id.grouptext);
					convertView.setTag(myView);//将封装成对象的自定义组件对象设置为convertView的Tag
				}else{
					myView=(MyView) convertView.getTag();
				}
				myView.imageView.setImageResource(imgarr[groupPosition]);
				myView.textView.setText(textarr[groupPosition]);
				return convertView;
			}
			
			@Override
			public long getGroupId(int groupPosition) {
				// TODO Auto-generated method stub
				return groupPosition;
			}
			
			@Override
			public int getGroupCount() {
				// TODO Auto-generated method stub
				return imgarr.length;
			}
			
			@Override
			public Object getGroup(int groupPosition) {
				// TODO Auto-generated method stub
				return null;
			}
			
			@Override
			public int getChildrenCount(int groupPosition) {
				// TODO Auto-generated method stub
				return childimgarr[groupPosition].length;
			}
			
			@Override
			public View getChildView(int groupPosition, int childPosition,
					boolean isLastChild, View convertView, ViewGroup parent) {
				MyView myView=null;
				if(convertView==null){
					convertView=LayoutInflater.from(MainActivity.this).inflate(R.layout.child_view, null);
					myView=new MyView();
					myView.imageView=(ImageView)convertView.findViewById(R.id.childimage);
					myView.textView=(TextView)convertView.findViewById(R.id.childtext);
					convertView.setTag(myView);
				}else{
					myView=(MyView) convertView.getTag();
				}
				myView.imageView.setImageResource(childimgarr[groupPosition][childPosition]);
				myView.textView.setText(childtextarr[groupPosition][childPosition]);
				return convertView;
			}
			
			@Override
			public long getChildId(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				return 0;
			}
			
			@Override
			public Object getChild(int groupPosition, int childPosition) {
				// TODO Auto-generated method stub
				return null;
			}
		};
		ExpandableListView e=(ExpandableListView)findViewById(R.id.extendview);
		e.setAdapter(bAdapter);
    }

至此已实现向ExpandableListView中填充数据