我是
Android开发的新手,也是第一次使用可扩展列表视图.我正在创建一个应用程序,其中我从webservice获取d可扩展列表视图的所有内容.我也从wevservice获取所有内容,但是当可扩展列表视图中没有父级的父项时,可扩展列表视图getchildcount()的自定义适配器方法返回null并给出空指针异常如何只显示列表中的父项两个都没有孩子和两个可用？
谢谢
public View getChildView(int p_id,int c_id,boolean bln1,View view,ViewGroup viewgroup) {
// TODO Auto-generated method stub
if (view == null) {
view = inflater.inflate(com.example.eventlive.R.layout.homescreen_list_item_child,viewgroup,false);
}
TextView textView = (TextView) view.findViewById(R.id.list_item_text_child);
//"i" is the position of the parent/group in the list and
//"i1" is the position of the child
textView.setText(mParent.get(p_id).getArrayChildren().get(c_id));
view.setBackgroundResource(R.drawable.child_bg);
//return the entire view
return view;
}
//counts the number of children items so the list knows how many times calls getChildView() method
@Override
public int getChildrenCount(int p_id) {
// TODO Auto-generated method stub
return mParent.get(p_id).getArrayChildren().size();
}
解决方法
只需初始化一个空的子数组,如下所示：
private HashMap<String,ArrayList<String>> mGroupsItems =
new HashMap<String,ArrayList<String>>();
. . .
mGroupsItems.put(name_of_empty_group,new ArrayList<String>());
