无法在表示正方形的节点上显示形状对象-JavaFX

Question

作为项目组，我们正在尝试创建一个遍历地图的代理。该地图是使用节点

创建的

此代码是定义的运动场。但是我无法显示新形状。有谁知道一种方法，这些形状可以稍后在其他班级中移动？

public double getgridWidth() {
    return gridWidth;
}
public double getgridHeight() {
    return gridHeight;
}

public static void main(String[] args) {
    launch(args);
}
Group root = new Group();


@Override
public void start(Stage primaryStage) {



    // initialize playfield
    for( int i=0; i < rowCells; i++) {
        for (int j = 0; j < columnCells; j++) {
            if (i == 0|| i==50) {
            Square test = new Square(i * gridWidth, j * gridHeight, gridWidth, gridHeight, false);
            root.getChildren().add(test);
            Rectangle borderWalls = new Rectangle(i * gridWidth, j * gridHeight, gridWidth, gridHeight);
            borderWalls.setHeight(gridHeight);
            borderWalls.setWidth(gridWidth);
            borderWalls.setStroke(Color.DARKSLATEGREY);
            borderWalls.setFill(Color.DARKSLATEGREY);
            root.getChildren().addAll(borderWalls);
            playfield[i][j] = test;
        }
    }

    for( int i=1; i < 49; i++) {
        for( int j=1; j < 49; j++) {

            // create node
            Square node = new Square( i * gridWidth, j * gridHeight, gridWidth, gridHeight, false);
            // add node to group
            root.getChildren().add(node);
            // add to playfield for further reference using an array
            playfield[i][j] = node;
        }
    }

    Run run = new Run();
    run.startTimer();

    Run noiseTimer = new Run();
    noiseTimer.startNoise();

        BorderPane pane = new BorderPane();
        Menu menu = new Menu(root);
    pane.setLeft(root);
    pane.setRight(menu.createMenu());
    Scene scene = new Scene( pane, windowWidth+menu.menuWidth, windowHeight);
    primaryStage.setScene( scene);
    primaryStage.show();
    primaryStage.setResizable(true);
    primaryStage.sizeToScene();
    primaryStage.setTitle("Multi Agent Surveillance");