Вы должны создать View
, как это
@Override
public CardViewDataAdapter.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
// create a new view
View itemLayoutView = LayoutInflater.from(viewGroup.getContext()).inflate(
R.layout.card_view, viewGroup, false);
// create ViewHolder
ViewHolder viewHolder = new ViewHolder(itemLayoutView);
return viewHolder;
}