如何使用KivyMD在NavigationDrawer中的屏幕之间切换

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen, ScreenManager

class HomeScreen(Screen):
    pass

class SettingsScreen(Screen):
    pass

class ScreenManagement(ScreenManager):
    pass

class MyApp(MDApp):
    def build(self):
        self.theme_cls.primary_palette = "BlueGray"
        return Builder.load_file("my.kv")

ScreenManagement:
    HomeScreen:
    SettingsScreen:

<HomeScreen>:
    name: "home"
    BoxLayout:
        orientation: "vertical"
        MDToolbar:
            title: "Home"
            left_action_items: [["menu", lambda x: app.root.toggle_nav_drawer()]]
        MDRaisedButton:
            text: "Go to Settings"
            on_release: app.root.current = "settings"

<SettingsScreen>:
    name: "settings"
    BoxLayout:
        orientation: "vertical"
        MDToolbar:
            title: "Settings"
            left_action_items: [["menu", lambda x: app.root.toggle_nav_drawer()]]
        MDRaisedButton:
            text: "Go to Home"
            on_release: app.root.current = "home"

<MyApp>:
    NavigationLayout:
        ScreenManager:
            ScreenManagement:
        MDNavigationDrawer:
            BoxLayout:
                orientation: "vertical"
                spacing: "8dp"
                padding: "8dp"
                Image:
                    source: "avatar.png"
                MDLabel:
                    text: "User Name"
                    font_style: "Subtitle1"
                    size_hint_y: None
                    height: self.texture_size[1]
                ScrollView:
                    MDList:
                        OneLineIconListItem:
                            text: "Home"
                            on_release: app.root.current = "home"
                            IconLeftWidget:
                                icon: "home"
                        OneLineIconListItem:
                            text: "Settings"
                            on_release: app.root.current = "settings"
                            IconLeftWidget:
                                icon: "settings"

python main.py