JavaFx KeyEvent不会移动对象

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.shape.Rectangle;
import javafx.stage.Stage;
import javafx.scene.input.KeyEvent;

public class ObjectMovement extends Application {

    private static final double MOVE_AMOUNT = 10.0;

    @Override
    public void start(Stage primaryStage) {
        Rectangle rectangle = new Rectangle(50, 50, 100, 100);

        Pane root = new Pane();
        root.getChildren().add(rectangle);

        Scene scene = new Scene(root, 400, 400);
        scene.setOnKeyPressed(this::handleKeyPress);

        primaryStage.setScene(scene);
        primaryStage.show();
    }

    private void handleKeyPress(KeyEvent event) {
        switch (event.getCode()) {
            case UP:
                moveObject(0, -MOVE_AMOUNT);
                break;
            case DOWN:
                moveObject(0, MOVE_AMOUNT);
                break;
            case LEFT:
                moveObject(-MOVE_AMOUNT, 0);
                break;
            case RIGHT:
                moveObject(MOVE_AMOUNT, 0);
                break;
            default:
                break;
        }
    }

    private void moveObject(double deltaX, double deltaY) {
        // 更新对象的位置
        // 例如：rectangle.setX(rectangle.getX() + deltaX);
        //      rectangle.setY(rectangle.getY() + deltaY);
    }

    public static void main(String[] args) {
        launch(args);
    }
}