ExpandableListView又称为可扩展的ListView组件，他和ListView组件很相似
不过每行的显示有两个xml文件，一个xml文件用于定义分组列表的显示风格，
还有一个xml文件用于定义分组下面的列表显示风格。如要显示如下图所示的风格
可以用如下代码实现：
public class Friend_manage extends Activity {
private static final String GROUP_TEXT = "group_text";// 大组成员Map的key
private Relationshipdao instanceRelationshipdao;//该对象用于获取数据源（由于该类涉及到数据库的操作，故没有给出源代码）
private List<Map<String, String>> groupData = new ArrayList<Map<String, String>>();// 大组成员
private List<List<User>> childDatalist = new ArrayList<List<User>>();// 小组成员
ExAdapter adapter;//将数据绑定到ExpandableListView组件上
ExpandableListView exList;// 可扩展的ListView
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.friend_manage);
instanceRelationshipdao = DaoFactory
.getinstanceRelationshipdao(Friend_manage.this);
List<User> childrenlist = new ArrayList<User>();
List<Relationship> rel_user_id = null;
for (int j = 0; j < 4; j++) {
rel_user_id = instanceRelationshipdao.getrelationship(
Login.user.getId(), j);
childrenlist = getUserbyRelationship(rel_user_id);
childDatalist.add(childrenlist);
}
// 为大小组中添加数据
Map<String, String> curGroupMap1 = new HashMap<String, String>();
Map<String, String> curGroupMap2 = new HashMap<String, String>();
Map<String, String> curGroupMap3 = new HashMap<String, String>();
Map<String, String> curGroupMap4 = new HashMap<String, String>();
curGroupMap1.put(GROUP_TEXT, "朋友(" + childDatalist.get(0).size() + ")");
groupData.add(curGroupMap1);
curGroupMap2.put(GROUP_TEXT, "亲人(" + childDatalist.get(1).size() + ")");
groupData.add(curGroupMap2);
curGroupMap3.put(GROUP_TEXT, "同学(" + childDatalist.get(2).size() + ")");
groupData.add(curGroupMap3);
curGroupMap4
.put(GROUP_TEXT, "陌生人(" + childDatalist.get(3).size() + ")");
groupData.add(curGroupMap4);
adapter = new ExAdapter(Friend_manage.this, childDatalist, groupData);
exList = (ExpandableListView) findViewById(R.id.list);
exList.setAdapter(adapter);
exList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v,
int groupPosition, int childPosition, long id) {
// TODO Auto-generated method stub
Bundle bundle=new Bundle();
bundle.putSerializable("user1", childDatalist.get(groupPosition).get(childPosition));
Intent intent=new Intent(Friend_manage.this, Friend_type_show.class);
intent.putExtras(bundle);
Friend_manage.this.startActivity(intent);
return false;
}
});
exList.setOnLongClickListener(new View.OnLongClickListener() {
@Override
public boolean onLongClick(View v) {
// TODO Auto-generated method stub
return false;
}
});
exList.setGroupIndicator(null);// 不设置大组指示器图标，因为我们自定义设置了
exList.setDivider(null);// 设置图片可拉伸的
}
// 根据List<Relationship>获取User表中的字段
public List<User> getUserbyRelationship(List<Relationship> rel_list) {
List<User> list = new ArrayList<User>();
Userdao instanceUserdao = DaoFactory
.getinstanceUserdao(Friend_manage.this);
if(rel_list!=null){
for (int i = 0; i < rel_list.size(); i++) {
list.add(instanceUserdao.getUserByid(rel_list.get(i).getUser_id()));
}
}
return list;
}
// 关键代码是这个可扩展的listView适配器
class ExAdapter extends BaseExpandableListAdapter {
private Context context;//该数据成员必不可少
//大小组的数据源可以自定义其数据类型，并不一定就是我这样
private List<List<User>> childdatalist;//小组列表的数据源
private List<Map<String, String>> groupData;//大组列表的数据源
public ExAdapter(Context context, List<List<User>> childdatalist,
List<Map<String, String>> groupData) {
super();
this.context = context;
this.childdatalist = childdatalist;
this.groupData = groupData;
}
// 得到大组成员的view
public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
View view = convertView;
if (view == null) {
LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.member_listview, null);//member_listview.xml文件用于定义GroupView的显示
}
TextView title = (TextView) view.findViewById(R.id.content_001);
title.setText(getGroup(groupPosition).toString());// 设置大组成员名称
ImageView image = (ImageView) view.findViewById(R.id.ImageView01);// 是否展开大组的箭头图标
if (isExpanded)// 大组展开时
image.setBackgroundResource(R.drawable.uyun_next_n);
else
// 大组合并时
image.setBackgroundResource(R.drawable.uyun_next_no);
return view;
}
// 得到大组成员的id
public long getGroupId(int groupPosition) {
return groupPosition;
}
// 得到大组成员名称
public Object getGroup(int groupPosition) {
return groupData.get(groupPosition).get(GROUP_TEXT).toString();
}
// 得到大组成员总数
public int getGroupCount() {
return groupData.size();
}
// 得到小组成员的view
public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
View view = convertView;
if (view == null) {
LayoutInflater inflater = LayoutInflater.from(context);
view = inflater.inflate(R.layout.member_childitem, null);//member_childitem.xml文件定义小组列表的显示风格
}
final TextView title = (TextView) view
.findViewById(R.id.child_text);
title.setText(childdatalist.get(groupPosition).get(childPosition)
.getName());// 大标题
final TextView title2 = (TextView) view
.findViewById(R.id.child_text2);
title2.setText(childdatalist.get(groupPosition).get(childPosition)
.getInfo());// 小标题
final ImageView seximage=(ImageView)view.findViewById(R.id.child_image);
if("男".equals(childdatalist.get(groupPosition).get(childPosition).getSex())){
seximage.setBackgroundResource(R.drawable.friends_man);
}else{
seximage.setBackgroundResource(R.drawable.friends_woman);
}
return view;
}
// 得到小组成员id
public long getChildId(int groupPosition, int childPosition) {
return childPosition;
}
// 得到小组成员的名称
public Object getChild(int groupPosition, int childPosition) {
return childdatalist.get(groupPosition).get(childPosition);
}
// 得到小组成员的数量
public int getChildrenCount(int groupPosition) {
return childdatalist.get(groupPosition).size();
}
public boolean hasStableIds() {
return true;
}
// 得到小组成员是否被选择
public boolean isChildSelectable(int groupPosition, int childPosition) {
return true;
}
}
}
member_listview.xml文件用于定义GroupView的显示，代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_gravity="center_horizontal"
android:orientation="horizontal">
<ImageView
android:id="@+id/ImageView01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:paddingTop="10dp">
</ImageView>
<TextView
android:id="@+id/content_001"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:paddingLeft="10dp"
android:textColor="#ff0000"
android:textSize="30sp" >
</TextView>
</LinearLayout>
member_childitem.xml文件定义小组列表的显示风格，代码如下：
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/childlayout"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" > <ImageView
android:id="@+id/child_image"
android:layout_width="50dip"
android:layout_height="60dip"
android:layout_marginLeft="40dp"
android:background="@drawable/friends_man"
android:paddingTop="10dp" >
</ImageView> <LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical" > <TextView
android:id="@+id/child_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:text=""
android:textColor="#000000"
android:textSize="25sp" >
</TextView> <TextView
android:id="@+id/child_text2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:gravity="center_vertical"
android:text=""
android:textColor="#000000"
android:textSize="20sp" >
</TextView>
</LinearLayout> </LinearLayout>