自定义过滤错误

Question

我正在尝试向SimpleAdapter添加自定义过滤器，我在publishResults方法中遇到错误。

代码是

private class TextCharFilter extends Filter{

    @Override
    protected FilterResults performFiltering(CharSequence constraint) {

        // convert search string to lower case - the filtering is not case sensitive
        constraint = constraint.toString().toLowerCase();

        // define the result object
        FilterResults result = new FilterResults();
        // define a place to hole the items that pass filtering         
        List<HashMap<String, String>> filteredItems = new ArrayList<HashMap<String,String>>();

        // loop through the original list and any items that pass filtering are added to the "filtered" list
        if(constraint != null && constraint.toString().length() > 0) {

            for(int i = 0; i < items.size(); i++) {
                HashMap<String, String> tmp = items.get(i);
                String candidate = tmp.get("PT").toLowerCase();

                if(candidate.contains(constraint) ) {
                    filteredItems.add(tmp);
                }
            }

            // set the result to the "filtered" list.
            result.count = filteredItems.size();
            result.values = filteredItems;

        }    
        else
        {
            // if nothing to filter on -  then the result is the complete input set
            synchronized(this)
            {
             result.values = items;
             result.count = items.size();
            }
        }
        return result;
    }

    @SuppressWarnings("unchecked")
    @Override
    protected void publishResults(CharSequence constraint, FilterResults results) {

        itemsFiltered = (List<HashMap<String, String>>)results.values;

        notifyDataSetChanged();
        clear();

        for (int i = 0; i < itemsFiltered.size(); i++){
            add(itemsFiltered.get(i));
        }


        notifyDataSetInvalidated();
    }

}

错误是找不到方法clear（）和add（itemsFiltered.get（i）） - 我哪里错了？该代码基于已发布的示例。