android - 适配器不工作

Question

在我的 OncreateView() 中设置在我第一次加载页面时工作的适配器。当我转到另一个页面并进行更改然后返回此 fragment 时，它不起作用 adapter.notifyDatasetchanged()。

 @Override
public void onStart() {
    super.onStart();
    groupItem.clear();
    childItem.clear();
    List<String> child_Category;child_Category=new ArrayList<String>();
    groupItem = obj_Listdatabase.fetchcategory();
    childItem.clear();
    ListIterator<String> iterator = groupItem
            .listIterator();
    while (iterator.hasNext()) {
        String categoryname = iterator.next();
        child_Category = new ArrayList<String>();
        child_Category = obj_Listdatabase
                .fetchchildlist(categoryname);
        childItem.add(child_Category);
    }

    adapter.notifyDataSetChanged();
}

Answer 1

Hai I got output for this one:

    groupItem.addAll(obj_Listdatabase.fetchcategory());

代替这个

   //groupItem = obj_Listdatabase.fetchcategory();

Because i change the reference in assignment statement(=) for that adapter.So i use addAll() method to store the values only instead of reference.