问在beeware中拥有多个布局的最正确方法是什么

EN

class HelloWorld(toga.App):
def startup(self):
    main_box = toga.Box(style=Pack(direction=COLUMN))

    name_label = toga.Label(
        'Your name: ',
        style=Pack(padding=(0, 5))
    )
    self.name_input = toga.TextInput(style=Pack(flex=1))

    name_box = toga.Box(style=Pack(direction=ROW, padding=5))
    name_box.add(name_label)
    name_box.add(self.name_input)

    button = toga.Button(
        'Say Hello!',
        on_press=self.say_hello,
        style=Pack(padding=5)
    )

    main_box.add(name_box)
    main_box.add(button)

    self.main_window = toga.MainWindow(title=self.formal_name)
    self.main_window.content = main_box
    self.main_window.show()

def say_hello(self, widget):
    print("Hello", self.name_input.value)