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。