如何从 kivy recycleview 中动态创建的按钮切换屏幕

Question

问题

如果有要处理的数据，我有一个屏幕 (OrderScreen)，其中填充有按钮。我希望用户单击其中一个按钮被带到另一个屏幕（MenuScreen）来处理数据。虽然我的意图是使用按钮中的数据填充下一个屏幕，但我目前只是试图让 ScreenManager 在按下按钮后更改为下一个屏幕。我在OrderButton 中添加了pass_data() 方法并尝试在那里触发屏幕管理器，但self.manager.current 和root.manager.current 正在引发异常。任何帮助将不胜感激。

recycleview_test.py

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from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.label import Label
from kivy.uix.recycleview import RecycleView
from kivy.uix.screenmanager import ScreenManager, Screen
from random import randint



class MenuScreen(Screen):
    def quit(self):
        App.get_running_app.stop()
        Window.close()

class OrderScreen(Screen):
    pass

class OrderButton(Button):
    def __init__(self, **kwargs):
        super(OrderButton, self).__init__(**kwargs)
        
    def pass_data(self):
        print("button pushed")

class OrderScroll(RecycleView):
    def __init__(self, **kwargs):
        super(OrderScroll, self).__init__(**kwargs)
        self.data = [{'text': str(f"Make {randint(10, 25)} items from package #{randint(1,4)}")} for x in range(12)]

class WindowManager(ScreenManager):
    pass

class RecycleApp(App):
    def build(self):
        return WindowManager()
    
if __name__ == "__main__":
    RecycleApp().run()

recycle.kv

#:import Factory kivy.factory.Factory
#: import ScreenManager kivy.uix.screenmanager.ScreenManager
#: import Screen kivy.uix.screenmanager.ScreenManager
#:import App kivy.app.App


<OrderScroll>:
    viewclass: 'OrderButton'
    manager: None
    RecycleBoxLayout:
        default_size: None, dp(56)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'
        padding: 20
        spacing: 10

<OrderButton>:
    manager: None
    font_size: 32
    bold: True
    on_release: 
        root.pass_data()

<WindowManager>:
    id: screen_manager
    OrderScreen:
        id: order_screen
        name: "OrderScreen"
        manager: screen_manager
    MenuScreen:
        id: menu_screen
        name: 'MenuScreen'
        manager: screen_manager

<OrderScreen>:
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Data Buttons"
            font_size: 64
            size_hint_y: None
            # pos_hint: {"x":0, "y":1} 
            height: 200
        OrderScroll:


<MenuScreen>:
    BoxLayout:
        orientation: "vertical"
        Label:
            text: "Made it"
            font_size: 64
        FloatLayout:
            Button:
                text: 'Keep going'
                font_size: 48
                size_hint: .8,.5
                pos_hint: {"center_x": .5, "center_y": .1}
        FloatLayout:
            Button:
                text: 'Quit'
                size_hint: .15,.3
                pos_hint: {"center_x": .5, "center_y": .5}
                on_release:
                    root.quit()
                    

Answer 1

尝试创建一个屏幕管理器对象：

class RecycleApp(App):
    def build(self):
        self.sm = WindowManager()
        return self.sm

然后通过以下方式访问它：

App.get_running_app().sm.current = 'MenuScreen' # in Python
app.sm.current = 'MenuScreen' # in kv