KIVY：如何将数据列表打印到第二个屏幕而不是第一个屏幕

Question

我的屏幕管理器正在工作，我可以在两个屏幕上显示我想要的信息，但在我的FirstWindow 上，我只想显示地点的名称（在本例中为A） .然后，当用户点击其中一个MDCard 时，它会将他们带到SecondWindow，在那里它将显示他们特别选择的位置的其余信息（在本例中为A AA AAA）。

我尝试创建一个列表，但是当您进入第二个屏幕时，它总是只返回 testz 列表中的最后一组元素。

对于示例，我已经尽可能地最小化了我的代码，我已经尝试了好几天了。感谢您的帮助！

*.py

import kivy
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import ObjectProperty
from kivy.properties import StringProperty
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.scrollview import ScrollView
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.clock import Clock
from kivy.uix.button import Button
from kivy.core.window import Window
from kivymd.app import MDApp
from kivymd.uix.card import MDCard
from kivymd.uix.label import MDLabel


class FirstWindow(Screen):
    def __init__(self, **kwargs):
        super(FirstWindow, self).__init__(**kwargs)
        Clock.schedule_once(self.create_scrollview)

    def create_scrollview(self, dt):
        layout = BoxLayout( orientation='vertical', spacing=25, size_hint_y=None, size_hint=(1, None) ,padding=[170, 10])
        layout.bind(minimum_height=layout.setter("height"))
        testz = [["A","AA","AAA"],["B","BB","BBB"],["C","CC","CCC"]]
        for x in testz:
            name = x[0]
            address = x[1]
            street = x[2]
            card = MDCard(orientation='vertical', size_hint=(1, None), height=200 ,padding=(20,0),ripple_behavior= True,radius=[5, ], elevation = 18)
            card.add_widget(MDLabel(text=name, halign= "center"))
            card.add_widget(MDLabel(text=address, halign= "left"))
            card.add_widget(MDLabel(text=street, halign= "left"))
            layout.add_widget(card)
            card.bind(on_touch_down=self.clicked) 

        scrollview = ScrollView(size_hint=(1, 1))
        self.view.add_widget(scrollview)
        scrollview.add_widget(layout)
        self.ids.house.text = "MAP"
    
    def clicked(self, card, touch):
        self.create_scrollview
        if card.collide_point(*touch.pos):
            FirstWindow.clicked.place_name = card.children[2].text
            FirstWindow.clicked.place_address = card.children[1].text
            FirstWindow.clicked.place_postcode = card.children[0].text
            self.manager.current = 'SecondWindow'
            
class SecondWindow(Screen):
    def on_pre_enter(self):
        self.ids.place_name.text = FirstWindow.clicked.place_name
        self.ids.place_address.text = FirstWindow.clicked.place_address
        self.ids.place_postcode.text = FirstWindow.clicked.place_postcode
    
    def test(self):
        self.manager.current = 'FirstWindow'

class ScreenSwitcher(ScreenManager):
    pass

class MainScreen(GridLayout):
    pass

class NearMeApp(MDApp):
    def build(self):
        self.theme_cls.theme_style ="Dark"
        self.theme_cls.accent_palette = "Red"
        self.theme_cls.primary_palette = "Blue"
        return MainScreen()

if __name__ == '__main__':
    NearMeApp().run()

*.kv

#:import hex kivy.utils.get_color_from_hex
#:kivy 1.10.1

<ToolBar@BoxLayout>:
    size_hint_y:None
    height: 50
    pos_hint: {'center_x': 0.5, 'top':1.0}
    canvas:
        Color:
            rgba: hex('#171717')
        Rectangle:
            pos: self.pos
            size: self.size
    Label:
        text:"NearMeApplication"

<FirstWindow>:
    name:"FirstWindow"
    view: view
   # NavBar:
    BoxLayout:
        orientation: 'vertical'
        canvas.before:
            Color:
                rgba: .2, .2, .2, 1
            Rectangle:
                pos: self.pos
                size: self.size

        BoxLayout:
            orientation: 'vertical'
            BoxLayout:
                size: (50, 50)
                size_hint: (1, None)
                Label:
                    id:house
                    halign: "center"
                    canvas.before:
                        Color:
                            rgba: 1, 1, 1, 1

            ScrollView:
                id: view 
                canvas.before:
                    Color:
                        rgba: 1, 1, 0, 1
                    #Line:
                        #width: 2
                        #rectangle: self.x, self.y, self.width, self.height
<SecondWindow>:
    name:"SecondWindow"
    AnchorLayout:
        size:1,1
        anchor_x: "center"
        anchor_y: "center"
        canvas.before:
            Color:
                rgba: .2, .2, .2, 1
            Rectangle:
                pos: self.pos
                size: self.size

        MDCard:
            orientation: "vertical"
            padding: "8dp"
            size_hint: 1,0.5
            pos_hint:{'top': 0.1,'right':1}
            radius:[5, ]
            elevation: 18

            MDLabel:
                id:place_name
                halign: "center"

            MDSeparator:
                height: "1dp"
            
            MDLabel:
                id:place_address
                halign: "center"
            MDLabel:
                id:place_postcode
                halign: "center"

    Button:
        text:"<--"
        size: 75, 50
        size_hint: None, None # <---
        on_press:
            root.manager.transition.direction = "left"
            root.test()
            #app.root.current = "FirstWindow"

# To keep the nav bar on all screens
<MainScreen>:
    rows: 2
    size_hint: 1, 1
    ToolBar:
    ScreenSwitcher:
        id: SS
        FirstWindow:
            name:'FirstWindow'
        SecondWindow:
            name:'SecondWindow'

Answer 1

您可以只将信息存储在MDCard 而不是MDLabels，如下所示：

def create_scrollview(self, dt):
    layout = BoxLayout(orientation='vertical', spacing=25, size_hint_y=None, size_hint=(1, None), padding=[170, 10])
    layout.bind(minimum_height=layout.setter("height"))
    testz = [["A", "AA", "AAA"], ["B", "BB", "BBB"], ["C", "CC", "CCC"]]
    for x in testz:
        name = x[0]
        address = x[1]
        street = x[2]
        card = MDCard(orientation='vertical', size_hint=(1, None), height=200, padding=(20, 0),
                      ripple_behavior=True, radius=[5, ], elevation=18)

        # store the needed info
        card.name = name
        card.address = address
        card.street = street

        card.add_widget(MDLabel(text=name, halign="center"))

        # don't add unwanted MDLabels
        # card.add_widget(MDLabel(text=address, halign="left"))
        # card.add_widget(MDLabel(text=street, halign="left"))

        layout.add_widget(card)
        card.bind(on_touch_down=self.clicked)

    scrollview = ScrollView(size_hint=(1, 1))
    self.view.add_widget(scrollview)
    scrollview.add_widget(layout)
    self.ids.house.text = "MAP"

然后在clicked() 方法中，您可以使用存储的信息：

def clicked(self, card, touch):
    self.create_scrollview
    if card.collide_point(*touch.pos):
        FirstWindow.clicked.place_name = card.name
        FirstWindow.clicked.place_address = card.address
        FirstWindow.clicked.place_postcode = card.street
        self.manager.current = 'SecondWindow'