python - 我无法从 kivymd 的另一个屏幕获取文本字段的值

Question

screen_helper = """
#:import utils kivy.utils
ScreenManager:
    id:screen_manager
    MenuScreen:
    RulesScreen:
    NumberPlayers:
    ProfileScreen:
    PlayersScreen:
    SettingsScreen:
<MenuScreen>:
    name: 'menu'
    MDRectangleFlatButton:
        text: 'Start'
        pos_hint: {'center_x':0.5,'center_y':0.6}
        on_press: 
            root.manager.current = 'number'
            root.manager.transition.direction= "left"
    MDRectangleFlatButton:
        text: 'Rules'
        pos_hint: {'center_x':0.5,'center_y':0.5}
        on_press: 
            root.manager.current = 'Rules'
            root.manager.transition.direction= "up"
    MDRectangleFlatButton:
        text: 'Settings'  
        pos_hint: {'center_x':0.5,'center_y':0.4}
        on_press: 
            root.manager.current = 'settings'
            root.manager.transition.direction= "down"
<NumberPlayers>:
    name: 'number'
    MDTextField:
        id: **numberfield**
        hint_text: 'Enter the number of players'
        helper_text: 'Max 4 users allowed'
        helper_text_mode: 'on_focus'
        color_mode: 'custom'
        line_color_focus: app.theme_cls.primary_color
        icon_right: 'account'
        required: True
        max_text_length: 4
        icon_right_color: app.theme_cls.primary_color
        pos_hint:{'center_x': 0.5, 'center_y': 0.5}
        size_hint_x:None
        width:300 
    MDRectangleFlatButton:
        text: 'Next'
        pos_hint:{'center_x': 0.75, 'center_y': 0.2} 
        on_press:
            app.disabling_button(numberfield.text,root)
    MDRectangleFlatButton:
        text: 'Back'
        pos_hint: {'center_x':0.25,'center_y':0.2}
        on_press: 
            root.manager.current = 'menu'
            root.manager.transition.direction= "right"

<RulesScreen>:
    name: 'Rules'
    MDLabel:
        text: 'Answer each question with different answers. All the answers will be shuffled randomly and in the end you will have many funny sentences'
        halign: 'center'
    MDRectangleFlatButton:
        text: 'Back'
        pos_hint: {'center_x':0.25,'center_y':0.2}
        on_press: 
            root.manager.current = 'menu'
            root.manager.transition.direction= "down"
<ProfileScreen>:
    name: 'profile'
    MDTextField:
        max_text_length: 10
        helper_text: 'You can enter 10 characters'
        helper_text_mode: 'on_focus'
        id:  profilefield
        hint_text: "Enter username for player 1"     
        icon_right: "account-key"
        required: True
        max_text_lenght: 12
        icon_right_color: app.theme_cls.primary_color
        pos_hint:{'center_x': 0.5, 'center_y': 0.5}
        size_hint_x:None
        width:300
    MDRectangleFlatButton:
        text: 'Back'
        pos_hint: {'center_x':0.25,'center_y':0.2}
        on_press: 
            root.manager.current = 'number'
            root.manager.transition.direction= "right"
    MDRectangleFlatButton:
        text:'Save'
        pos_hint:{'center_x': 0.75, 'center_y': 0.2}
        on_press: 
            app.disabling_button2(profilefield.text,root)

<Label>
    background_color: (1,1,1,0)
    canvas.before:
        Color:
            rgba: self.background_color
        Rectangle:
            size: self.size
            pos: self.pos
     # label text color
    color:app.theme_cls.primary_color

<PlayersScreen>:
    name: 'players'
    MDRectangleFlatButton:
        text: 'Back'
        pos_hint: {'center_x':0.25,'center_y':0.2}
        on_press: 
            root.manager.current = 'profile'
            root.manager.transition.direction= "right"
        
    MDRectangleFlatButton:
        text:'Save'
        pos_hint:{'center_x': 0.75, 'center_y': 0.2}
        on_press:
            root.manager.current = 'results'

    GridLayout:
        cols: 1
        pos: 0,0
        size: root.width , root.height #take size of entire screen
        BoxLayout:
            orientation: "vertical"
            size: root.width, root.height # fot take entire screen
            spacing: 0 # space btween buttons
            padding: 130
            Label:
                text: "Who?"

            MDTextField:
                id: who
                multiline: False
            Label:
                text: "With whom"

            MDTextField:
                id: whom
                multiline: False
            Label:
                text: "What does?"

            MDTextField:
                id: whatdoes
                multiline: False
            Label:
                text: "When?"

            MDTextField:
                id: when
                multiline: False
            Label:
                text: "Where?"

            MDTextField:
                id: where
                multiline: False
            Label:
                text: ''
                id: result
                font_size: 20


<SettingsScreen>:
    name: 'settings'
    MDSwitch:
        pos_hint: {'center_x':0.5,'center_y':0.5}
        on_active: app.on_switch_active(self.active)
    MDLabel:
        text: 'Light Mode'
        pos_hint: {'center_x':0.3,'center_y':0.5}
        halign: 'center'
        font_style: 'Subtitle2'
    MDLabel:
        text: 'Dark Mode'
        pos_hint: {'center_x':1.15,'center_y':0.5}
        haligh: 'center'
        font_style: 'Subtitle2'
    MDRectangleFlatButton:
        text:'Go back to main menu'
        pos_hint: {'center_x':0.5,'center_y':0.4}
        on_press: root.manager.current = 'menu'

        






"""

from kivymd.app import MDApp
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager
from kivymd.uix.screen import Screen
from kivy.lang import Builder
from helper import screen_helper
from kivymd.uix.textfield import TextInput


class MenuScreen(Screen):
    pass


class NumberPlayers(Screen):
    pass


class ProfileScreen(Screen):
    pass


class RulesScreen(Screen):
    pass


class PlayersScreen(Screen):
    pass


class SettingsScreen(Screen):
    pass


# Create the screen manager
sm = ScreenManager()
sm.add_widget(MenuScreen(name='menu'))
sm.add_widget(ProfileScreen(name='profile'))
sm.add_widget(RulesScreen(name='Rules'))
sm.add_widget(PlayersScreen(name='players'))
sm.add_widget(NumberPlayers(name='number'))
sm.add_widget(SettingsScreen(name='settings'))


class DemoApp(MDApp, NumberPlayers):

    def build(self):
        self.theme_cls.primary_palette = "Blue"
        screen = Screen()
        self.username = Builder.load_string(screen_helper)
        screen.add_widget(self.username)

        return screen

    def on_switch_active(self, value):
        if value:
            self.theme_cls.theme_style = "Dark"
        else:
            self.theme_cls.theme_style = "Light"

    def disabling_button(self, empty, root):
        if empty and len(empty) < 5:
            root.manager.current = 'profile'

        else:
            self.disabled = True

    def disabling_button2(self, empty, root):
        if empty and len(empty) < 11:
            root.manager.current = 'players'
            root.manager.transition.direction = 'left'
        else:
            self.disabled = True

这是 main.py 我应该得到一个 id 为 numberfield 的 textfield 的值。我是 kivy 和 kivymd 的新学习者。任何人都可以帮助我在这个文本字段中获得输入吗？我尝试使用 .ids.numberfield.text 方法，但是当我尝试它时出现错误，提示“在 MDApp 中找不到属性 ID”

标签： pythonkivykivy-languagekivymd