如何在JavaFX中更新节点状态？

public Card(Suit suit, Rank rankString, boolean hide) {
        this.suit = suit;
        this.rankString = rankString;
        this.hide = hide;

        if (!this.hide) {
            HashMap<String, String> map = cardNames();
            String thisCard = suit.toString()+rankString.toString();

            Image cardDP = new Image("file:E:/Javaworkspace/Project/resource/"+ map.get(thisCard) +".png");
            ImageView iv = new ImageView();
            iv.setImage(cardDP);
            getChildren().add(new StackPane(iv));

        } else {
            Image img = new Image("file:E:/Javaworkspace/Project/resource/blank.png");
            ImageView iv = new ImageView();
            iv.setImage(img);
            getChildren().add(new StackPane(iv));
        }

    }
public Card(Suit suit, Rank rankString, boolean