JavaFX如何将内容分配给子节点UI控制器

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.FlowPane;
import javafx.stage.Stage;

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) {
        // 创建父节点
        FlowPane root = new FlowPane();

        // 创建子节点UI控制器
        Button button1 = new Button("Button 1");
        Button button2 = new Button("Button 2");
        Button button3 = new Button("Button 3");

        // 将子节点添加到父节点中
        root.getChildren().addAll(button1, button2, button3);

        // 创建场景并将父节点设置为根节点
        Scene scene = new Scene(root, 300, 200);

        // 设置舞台的场景
        primaryStage.setScene(scene);
        primaryStage.setTitle("JavaFX UI");
        primaryStage.show();
    }

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