Kivy屏幕管理

Question

如何在程序启动时让主店打开而不是商店

该程序有一个菜单和三个屏幕。我启动时需要打开主屏幕而不是商店

也许还有一个选项可以从菜单中删除图标，以便菜单是文本，反之亦然

主.py

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.core.window import Window
from kivy.utils import get_color_from_hex
from kivy.core.text import LabelBase

Window.size = (430, 930)

class ShopScreen(Screen):
    pass

class ItemsScreen(Screen):
    pass

class HomeScreen(Screen):
    Builder.load_file("Home.kv")

class WindowManager(FloatLayout):
    pass

class MainApp(MDApp):
    def build(self):
        self.theme_cls.theme_style = "Dark"
        sm = ScreenManager()
        sm.add_widget(ShopScreen(name='menu'))
        sm.add_widget(ItemsScreen(name='items'))
        sm.add_widget(HomeScreen(name='main'))
        Builder.load_file("main.kv")
        return WindowManager()


if __name__ == "__main__":
    LabelBase.register(name="Press Start 2P",
                    fn_regular='./font/PressStart2P-Regular.ttf')
    MainApp().run()

主.kv

#: import get_color_from_hex kivy.utils.get_color_from_hex
<WindowManager>:
    MDBottomNavigation: 
        font_name: "./font/PressStart2P-Regular.ttf"
        panel_color: get_color_from_hex("#1B1B1B")
        text_color_active: 1, 1, 0, 1
        MDBottomNavigationItem:
            icon: 'home'
            name: 'shop'
            text: 'МАГАЗИН'
 
        MDBottomNavigationItem:
            icon: 'home'
            name: 'main'
            text: 'ГОЛОВНА' 
            HomeScreen:
  
        MDBottomNavigationItem:
            icon: 'home'
            name: 'items'
            text: 'ХЕЛПЕРИ'

Answer 1

简短回答：

将要首先启动的屏幕行移动到顶部位置，如下所示：

class MainApp(MDApp):
    def build(self):
        self.theme_cls.theme_style = "Dark"
        sm = ScreenManager()
        sm.add_widget(HomeScreen(name='main'))
        sm.add_widget(ItemsScreen(name='items'))
        sm.add_widget(ShopScreen(name='menu'))
        Builder.load_file("main.kv")
        return WindowManager()

长答案：在 ScreenManager() 的开头，您正在定义屏幕的顺序。您不能直接从其他屏幕调用这些屏幕。也许这就是你想要的。但是，这里有一个如何实现它的示例：

class MainApp(MDApp):
    def build(self):
        self.theme_cls.theme_style = "Dark"
        sm = ScreenManager()
        sm.add_widget(HomeScreen(name='main'))
        sm.add_widget(ItemsScreen(name='items'))
        sm.add_widget(ShopScreen(name='menu'))

        return sm

        Builder.load_file("main.kv")
        return WindowManager()

当您在另一个屏幕时，您可以使用此代码切换到另一个屏幕。

# In another class, for example, a button event or somewhere else where you have access to the `MainApp` instance
from kivy.uix.screenmanager import ScreenManager

class SomeClass:
    def some_method(self):
        # Get the instance of MainApp and Access the ScreenManager of MainApp
        screen_manager = MainApp.get_running_app().screen_manager

        # Change the currently displayed screen to 'menu'
        screen_manager.current = 'menu'

我希望这对你有帮助。