Java等待组件被绘制

import javax.swing.*;

public class MyGui {
  public static void main(String[] args) {
    JFrame frame = new JFrame("My GUI");
    frame.setSize(400, 600);

    JPanel panel = new JPanel();
    JLabel label = new JLabel("This is a simple GUI.");
    JButton button = new JButton("Click Me!");

    panel.add(label);
    panel.add(button);

    frame.add(panel);
    frame.setVisible(true);
  }
}

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.stage.Stage;

public class MyGui extends Application {
  public static void main(String[] args) {
    launch(MyGui.class, args);
  }

  @Override
  public void start(Stage primaryStage) {
    StackPane root = new StackPane();
    root.setMinWidth(400);
    root.setMinHeight(600);

    Label label = new Label("This is a simple GUI.");
    Button button = new Button("Click Me!");

    root.getChildren().addAll(label, button);

    Scene scene = new Scene(root);
    primaryStage.setScene(scene);
    primaryStage.show();
  }
}