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我的任务是在过滤期间保持展开/折叠的组。我编写了自己的过滤器，如果组没有任何孩子，则删除组。但是在组消失后，过滤器的文本被更改并且组返回，但它会被折叠。

所以我保存展开/折叠状态来分组对象。所以我只需要在适当的时候应用这些状态。

有我的尝试：

class SubjectGroupList extends ExpandableListView implements OnGroupCollapseListener, OnGroupExpandListener{

    public SubjectGroupList(Context context) {
        super(context);
    }

    public void onGroupExpand(int groupPos) {
        SubjectGroup group = (SubjectGroup)getExpandableListAdapter().getGroup(groupPos);
        group.expanded = true;
    }

    public void onGroupCollapse(int groupPos) {
        SubjectGroup group = (SubjectGroup)getExpandableListAdapter().getGroup(groupPos);
        group.expanded = false;
    }

    @Override 
    public void onFilterComplete(int count) {
        fixCollapse();

        super.onFilterComplete(count);
    }

    private void fixCollapse() {
        Log.d("SubjectGroupList", "fix collapse");

        SubjectGroupAdapter adapter = (SubjectGroupAdapter)getExpandableListAdapter();
        int i = adapter.getGroupCount();
        while (--i >= 0)
            if (adapter.getGroup(i).expanded)
                expandGroup(i);
            else
                collapseGroup(i);
    }
}

但这根本不起作用。永远不会调用onFilterComplete方法。

我必须找到另一种方法来确定，在重新绘制之前何时应用过滤器。

也许有人知道？谢谢。

编辑：

我的过滤器：

class GroupFilter extends Filter {
    private SubjectGroupAdapter adapter;

    public GroupFilter(SubjectGroupAdapter adapter) {
        this.adapter = adapter;
    }

    @Override
    protected FilterResults performFiltering(CharSequence s) {
        FilterResults result = new FilterResults();
        result.count = 0;

        ArrayList<SubjectGroup> groups = new ArrayList<SubjectGroup>();

        s = s.toString().toLowerCase();

        for (SubjectGroup group : adapter.ori) {
            SubjectGroup ng = new SubjectGroup(group.name, group.id);

            int founded = 0;
            for (SubjectItem item : group) {
                if (s == null || s.length() == 0 || item.name.toLowerCase().contains(s)) {
                    ng.add(new SubjectItem(item.name, item.id));
                    result.count++;
                    founded++;
                }
            }

            if (founded > 0)
                groups.add(ng);
        }

        result.values = groups;

        return result;
    }

    @Override
    protected void publishResults(CharSequence s, FilterResults result) {
        adapter.filter((ArrayList<SubjectGroup>) result.values);
    }
}

*以及接受过滤数据的适配器方法 * :

protected void filter(ArrayList<SubjectGroup> groups) {
    this.groups = groups;
    notifyDataSetInvalidated();
}
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1 回答 1

1

我创立了答案。

I can register DataSetObserver to Adapter, who listens for data changes or invalidate. So I register observer in ExpandableListView by overriding addAdapter method:

@Override
public void setAdapter(ExpandableListAdapter adapter) {
    adapter.registerDataSetObserver(new DataSetObserver() {
        public void onInvalidated() {
            fixCollapse();
        }
    });

    super.setAdapter(adapter);
}

Also I need tweak a bit Filter, because there was the mistakes.

It work very well. I hope someone else helps my experience.

于 2012-07-20T08:07:48.520 回答