In JavaFX, a MenuBar is a container for menus in a user interface. Here's an example of how to create and use a MenuBar control:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Menu;
import javafx.scene.control.MenuBar;
import javafx.scene.control.MenuItem;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;

public class MyJavaFXApp extends Application {
    
    @Override
    public void start(Stage primaryStage) {
        // Create some menu items
        MenuItem menuItem1 = new MenuItem("Option 1");
        MenuItem menuItem2 = new MenuItem("Option 2");
        MenuItem menuItem3 = new MenuItem("Option 3");
        
        // Create a menu and add the menu items to it
        Menu menu = new Menu("File");
        menu.getItems().addAll(menuItem1, menuItem2, menuItem3);
        
        // Create a menu bar and add the menu to it
        MenuBar menuBar = new MenuBar();
        menuBar.getMenus().add(menu);
        
        // Put the menu bar in a layout container
        BorderPane borderPane = new BorderPane();
        borderPane.setTop(menuBar);
        
        // Create a scene and set it on the stage
        Scene scene = new Scene(borderPane, 300, 250);
        primaryStage.setScene(scene);
        
        // Show the stage
        primaryStage.show();
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

In this example, we create three MenuItem controls and add them to a Menu control. We then create a MenuBar control and add the Menu control to it. We put the MenuBar in a BorderPane layout container and create a scene with the BorderPane. Finally, we set the scene on the stage and show the stage. When the user clicks on a menu item, the program will perform some action, depending on how you set the action.