android：使用BaseExpandableListAdapter实现可折叠的列表

使用BaseExpandableListAdapter 可以实现所谓的可折叠的列表，例如QQ里好友的分组的功能。

BaseExpandableListAdapter与BaseAdapter的基本原理是一样的，只不过在传入list的时候，要传入两组，一组是groupArray ，一组时childArray，前者用于组名（类似QQ的好友、同学、朋友），后者的每个元素都是一组子数据（类似QQ同学中的张三，李四的集合），实现adapter

public class ExpandableAdapter extends BaseExpandableListAdapter{

private LinkedList<TeacherSumGroupsModel> groupArray;
private List<LinkedList<TeacherSumGroupDetailModel>> childArray;
private Context context;
private LayoutInflater inflater;

public ExpandableAdapter(Context context,LinkedList<TeacherSumGroupsModel> courseGroupList,
List<LinkedList<TeacherSumGroupDetailModel>> childArray){
inflater = ((Activity) context).getLayoutInflater();

this.groupArray = courseGroupList;
this.childArray = childArray;
}

public int getGroupCount() {
// TODO Auto-generated method stub
return groupArray.size();
}

public int getChildrenCount(int groupPosition) {
// TODO Auto-generated method stub
return childArray.get(groupPosition).size();
}

public Object getGroup(int groupPosition) {
// TODO Auto-generated method stub
return groupArray.get(groupPosition);
}

public Object getChild(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return childArray.get(groupPosition).get(childPosition);
}

public long getGroupId(int groupPosition) {
// TODO Auto-generated method stub
return groupPosition;
}

public long getChildId(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return childPosition;
}

public boolean hasStableIds() {
// TODO Auto-generated method stub
return false;
}

public View getGroupView(int groupPosition, boolean isExpanded,
View convertView, ViewGroup parent) {
// TODO Auto-generated method stub

TextView title;

if(convertView == null){
convertView = inflater.inflate(R.layout.simple_listview_item, parent, false);
}
title = (TextView) convertView.findViewById(R.id.simple_listview_textview);
String t = "     "+groupArray.get(groupPosition).getname();
title.setText(t);
return convertView;
}

public View getChildView(int groupPosition, int childPosition,
boolean isLastChild, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
TextView title;

if(convertView == null){
convertView = inflater.inflate(R.layout.simple_listview_item, parent, false);
}
title = (TextView) convertView.findViewById(R.id.simple_listview_textview);

String account = childArray.get(groupPosition).get(childPosition).getAccount();
String name = childArray.get(groupPosition).get(childPosition).getName();
String t = account +"          "+name;
Log.e("sumlist", "info is " +t);
title.setText(t);
return convertView;
}

public boolean isChildSelectable(int groupPosition, int childPosition) {
// TODO Auto-generated method stub
return true;
}

}

代码摘自现在的某个项目。

类似与BaseAdapter的关键getView方法，这里比较重要的是getGroupView和getChildView方法，其实内部实现都是类似的。