Kivy self manager屏幕不工作

2024-06-06 13:10:50 发布

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最近我尝试用python和kivy制作这个应用程序。在用谷歌搜索了好几个小时后，我或多或少得到了我想要的一切。只缺少一件事：

我有几个屏幕。在应用程序的开头，我有一个菜单。之后我有很多问题；它们在屏幕底部都有相同的文本和按钮。我设法做到了以下几点：

<firstquestion>:
    name: "firstquestion"

    GridLayout:
        cols: 1
        size_hint_y: 1

        GridLayout:
            cols: 1

                NeuLabelinBox:
                    text: "Here the Question"

        GridLayout:
            cols: 1
            size_hint_y: 0.1

            UnteresMenue:

请注意“UnteresMenue”，它引用了kv语言中的另一个类。我想我把两个屏幕混在了一起。“UnteresMenue”的kv代码

<UnteresMenue>:
    name: "UnteresMenue"
    #id: UnteresMenue


    GridLayout:
        cols: 1

        NeuButton: 
            text: root.labeltext

现在来看python部分：

class UnteresMenue(Screen):
    labeltext = StringProperty("Answer")

那很好。但现在，当我按下应用程序开头的某个按钮（开始提问）时，我想更改此“UnteresMenue”中标签的文本。“Untermenue”中的标签应更改为特定文本。因此，要做到这一点：

text: "Exam"
self.manager.get_screen('UnteresMenue').labeltext = text

对于所有其他类，此方法都可以正常工作。但不是针对某个类“UnteresMenue”。是因为它是在问题中实现的，因此kv不承认它的属性吗

对于任何小小的提示，我将不胜感激

这里有一个“迷你”示例：

在主菜单中，您可以进入“考试”部分（按示例中的此处）。进入本节（Prüfungsmodus）时，问题的性质应该改变。再次“按此处”进入问题

通常，它在问题的顶部说“这应该改变”，这应该在进入Prüfungsmodus屏幕时将标签改为“Zeit”（python文件中enter上的Class def），但它没有

Python文件：

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, TransitionBase
from kivy.properties import ObjectProperty, NumericProperty
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.core.text import LabelBase

from kivy.core.window import Window
from kivy.graphics import Color, InstructionGroup, Line, Rectangle
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button

from kivy.properties import ListProperty
from kivy.uix.textinput import TextInput
from kivy.uix.checkbox import CheckBox
from kivy.uix.widget import Widget
from kivy.config import Config
from kivy.properties import StringProperty
from kivy.clock import Clock
from functools import partial
from kivy.uix.image import Image

from kivy.garden.navigationdrawer import NavigationDrawer as ND

from kivy.uix.scatter import Scatter
import random 
import time

Window.clearcolor = (0.2,0.2, 0.2,1)
Window.size = (480, 800)


#---------------------------------             Hauptmenü           -------------------------------------------

class hauptmenue(Screen, Widget):
    pass

class Pruefungsmodus(Screen):


    labeltext2 = StringProperty("hi")


    def on_enter(self):
        text = "Zeit" 

        self.manager.get_screen('OberesMenue').labeltext = text  #DAS Klappt nicht

    def StartPruefung(self):


        sm.current = "ersteFrage"  


class UnteresMenue(Screen):

    background_color_Kappa = ListProperty([0.2,0.2,0.2, 1]) 


class OberesMenue(Screen):

    BildLabeltext = StringProperty("Bilder\Loesung_Bild_pressed.png")
    BildLabeltext2 = StringProperty("Bilder\Loesung_Bild.png")
    labeltext = StringProperty("This should change")



class ersteFrage(Screen):

    pass





class WindowManager(ScreenManager):

    pass




kv = Builder.load_file("my.kv")
sm = WindowManager()


sm.add_widget(hauptmenue(name="hauptmenue"))



sm.add_widget(Pruefungsmodus(name="Pruefungsmodus"))       

sm.add_widget(OberesMenue(name="OberesMenue"))    
sm.add_widget(UnteresMenue(name="UnteresMenue"))   
sm.add_widget(ersteFrage(name="ersteFrage"))  
sm.current = "hauptmenue"






class Vorbrereitung(App):
    pruefung = ObjectProperty(None)
    def build(self):

        return sm

if __name__ == "__main__":
    Vorbrereitung().run()

my.kv文件：





#:include alleFragen.kv

<NeuLabel2@Label>:


    halign: "center" 
    color:1,1,1,1 # <-----------
    canvas.before:
        Color:
            rgba: 0.2,0.2, 0.2,1
        Rectangle:
            pos: self.pos
            size: self.size  


<NeuLabelinBox@Label>:


    font_size: "22sp"
    color:0,0,0,1 # <-----------
    canvas.before:
        Color:
            rgba: 0.949019608,  0.949019608,  0.949019608, 1
        Rectangle:
            pos: self.pos
            size: self.size  

<NeuCheckBox@CheckBox>:

    color: 0, 0, 0, 1
    canvas.before:
        Color:
            rgba: 0.949019608,  0.949019608,  0.949019608, 1
        Rectangle:
            pos: self.pos
            size: self.size  


<NeuButton@Button>:

    font_size: "22sp"

    background_normal: ''
    #background_normal: "background.png"
    background_color: 0.92549,0.92549,0.92549, 1
    color:0,0,0,1 # <-----------
    canvas.before:
        Color:
            rgba: 0.2,0.2, 0.2,1
        Rectangle:
            pos: self.pos
            size: self.size   


<NeuButtonKappa@Button>:

    font_size: "40sp"

    background_normal: ''

    background_color: 0.2,0.2,0.2, 1
    color:1,1,1,1 # <-----------
    canvas.before:
        Color:
            rgba: 0.2,0.2, 0.2,1
        Rectangle:
            pos: self.pos
            size: self.size              

#----------------------------------            Hauptmenue          ---------------------------------------------------------------------------------

<hauptmenue>:
    name: "Hauptmenue"

    GridLayout:
        cols:1

        #spacing: 20


        GridLayout:
            cols:1
            padding: 20
            size_hint_y: 0.2           


            NeuLabel2:
                size_hint_x: 0.6
                text: ""
                font_size: (root.width**2 + root.height**2) / 13**4
                halign: 'center'
                valign: 'middle'


        GridLayout:
            cols:2
            padding: 30
            spacing: 20

            size_hint_y: 0.5
            BoxLayout:
                NeuButton:
                    text: ''

            BoxLayout:
                NeuButton:
                    text: 'PRESS HERE'
                    on_release:
                        app.root.current = "Pruefungsmodus"
            BoxLayout:
                NeuButton:
                    text: ""
                    halign: 'center'
                    valign: 'middle'

            BoxLayout:
                NeuButton:
                    text: ""
        BoxLayout:
            padding: 10
            size_hint_y: 0.15

            NeuButton:
                text: ''

#----------------------------------            Pruefungsmodus          ---------------------------------------------------------------------------------

<Pruefungsmodus>:
    name: "Pruefungsmodus"
    #background_color: 1, 1, 1, 1
    id: pruefungsmudos

    GridLayout:
        cols:1

        #spacing: 20


        GridLayout:
            cols:3
            padding: 20
            size_hint_y: 0.2           
            Image:
                size_hint_x: 0.2
                source:"Bilder\Logo.png"   

            NeuLabel2:
                size_hint_x: 0.6
                text: 'Pr\u00FCfungs\nmodus'
                font_size: (root.width**2 + root.height**2) / 12**4
                halign: 'center'
                valign: 'middle'

            Image:
                size_hint_x: 0.2
                source:"Bilder\Logo2.png"     


        GridLayout:
            cols:1
            padding: 30
            spacing: 10

            size_hint_y: 0.4
            NeuLabelinBox:
                id: text2
                text: root.labeltext2
                color: 0,0,0,1 # <-----------
                canvas.before:
                    Color:
                        rgba: 0.949019608,  0.949019608,  0.949019608, 1
                    Rectangle:
                        pos: self.pos
                        size: self.size 

        GridLayout:
            cols:2
            padding: 30

            size_hint_y: 0.2    

            BoxLayout:
                padding: 30
                spacing: 10
                NeuButton:
                    size_hint_x: 0.5
                    text: "Press Here" 
                    on_release:
                        app.root.current = "ersteFrage"



                NeuButton:
                    size_hint_x: 0.5
                    text: ""
                    on_release:
                        app.root.current = "hauptmenue"

#----------------------------------             Erste Frage           ---------------------------------------------------------------------------------

<ersteFrage>:
    name: "ersteFrage"


    GridLayout:
        cols: 1
        size_hint_y: 1

        GridLayout:
            cols: 1
            size_hint_y: 0.08

            OberesMenue:


        GridLayout:
            cols: 1

            size_hint_y: 0.1 

            NeuLabel2:
                font_size: "18sp"
                text: "Wie lautet......."        


        GridLayout:
            cols: 1


            size_hint_y: 0.7

            padding: 20
            background_color: 0.92549,0.92549,0.92549, 1  
            rows: 2
            BoxLayout:
                orientation:'horizontal'
                NeuLabelinBox:
                    text: "h+u=ZU" 
                NeuCheckBox:

                NeuLabelinBox:
                    text: "h+u=ZU"                    
                NeuCheckBox:

            BoxLayout:
                orientation:'horizontal'

                NeuLabelinBox:

                    text: "h+u=ZU" 
                NeuCheckBox:

                NeuLabelinBox:
                    text: "h+u=ZU"

                NeuCheckBox:

        GridLayout:
            cols: 1


            size_hint_y: 0.1


            UnteresMenue:

以及外包的顶部和按钮菜单： alleFragen.kv

<OberesMenue>:
    id: OberesMenueee

    name: "OberesMenue"


    GridLayout:
        cols:1
        GridLayout:
            #size_hint_y: 0.05
            spacing: 20

            cols: 3
            NeuButton:
                text: ""
                size_hint_x: 0.16

                background_color: 1,1,1, 1
                background_down:  root.BildLabeltext
                background_normal:  root.BildLabeltext2
                color:1,1,1,1 # <-----------
                canvas.before:
                    Color:
                        rgba: 0.2,0.2, 0.2,1
                    Rectangle:
                        pos: self.pos
                        size: self.size  

            NeuLabel2:

                size_hint_x: 0.8 

                text: root.labeltext

            NeuButtonKappa: 
                size_hint_x: 0.1 
                text: "MENU"
                background_down: "Bilder\HintergurndFarbe_app.png"
                on_release:
                    app.root.current = "hauptmenue"


<UnteresMenue>:
    name: "UnteresMenue"
    id: UnteresMenuee


    GridLayout:
        cols: 5
        spacing: 20
        padding: 20
        NeuButton: 
            text: "<=="

        NeuButton: 
            text: "<"

        NeuButtonKappa: 
            text: 'k'
            #background_color: root.background_color_Kappa
            background_down:  "Bilder\HintergurndFarbe_app.png"

        NeuButton: 
            text: ">"

        NeuButton: 
            text: "==>"

Tags： textfromposimportselfsizerootcolor
1条回答
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1楼 · 发布于 2024-06-06 13:10:50

问题是OberesMenue屏幕有两个不同的实例

在python中创建了一个：

sm.add_widget(OberesMenue(name="OberesMenue"))

您在kv中创建了另一个：

<ersteFrage>:
    name: "ersteFrage"


    GridLayout:
        cols: 1
        size_hint_y: 1

        GridLayout:
            cols: 1
            size_hint_y: 0.08

            OberesMenue:

为了访问OberesMenue的第二个实例，您可以添加一个id：

<ersteFrage>:
    name: "ersteFrage"


    GridLayout:
        cols: 1
        size_hint_y: 1

        GridLayout:
            cols: 1
            size_hint_y: 0.08

            OberesMenue:
                id: in_ersteFrage

然后，在Pruefungsmodus的on_enter()方法中，可以使用以下命令更改该实例：

def on_enter(self):
    text = "Zeit"

    self.manager.get_screen('ersteFrage').ids.in_ersteFrage.labeltext = text  #DAS Klappt nicht

请注意，这会更改OberesMenue的第二个实例中的Label，但对第一个实例没有影响。您的原始代码正在更改第一个实例，但没有更改第二个实例。而且不能同时在两个地方放置同一个实例，因为Widget一次只能有一个父对象

因此，如果这些实例是相同的，那么您需要更改这两个实例中的Label

如果您确实想要共享同一个实例，您可以保存自己的实例所在位置记录，并使用remove_widget()和add_widget()将其从一个父级移动到另一个父级

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