清除过滤器后，Recyclerview列表数据无法恢复

如何解决清除过滤器后，Recyclerview列表数据无法恢复

我尝试使用过滤器实现recyclerview。但是我的recyclerview列表在清除过滤器后无法恢复..仅显示空白数据 这是我的代码

 public IkanAdapter(Context context,List<Ikan> ikanList,ContactsAdapterListener listener) {
    this.context = context;
    this.ikanList = ikanList;
    this.listener = listener;
    this.ikanListFiltered = ikanList;
}

  
public Filter getFilter() {
    return new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence charSequence) {
            String charString = charSequence.toString();
            if (charString.isEmpty()) {
                ikanListFiltered = ikanList;
            } else {
                List<Ikan> filteredList = new ArrayList<>();
                for (Ikan row : ikanList) {
                    if (row.getTxnama().toLowerCase().contains(charString.toLowerCase())) {
                        filteredList.add(row);
                    }
                }
                ikanListFiltered = filteredList;
            }

            FilterResults filterResults = new FilterResults();
            filterResults.values = ikanListFiltered;
            return filterResults;
        }

        @Override
        protected void publishResults(CharSequence charSequence,FilterResults filterResults) {
            ikanList.clear();
            ikanList.addAll((List<Ikan>) filterResults.values);
            ikanListFiltered = (ArrayList<Ikan>) filterResults.values;
            notifyDataSetChanged();
        }
    };
}

请帮助...我很困惑