Kivy：self.parent.current 没有使用屏幕管理器将我重定向到不同的屏幕答案

【问题标题】：Kivy: self.parent.current not redirecting me to different screen using screen managerKivy：self.parent.current 没有使用屏幕管理器将我重定向到不同的屏幕
【发布时间】：2020-07-23 22:41:16
【问题描述】：

使用 Kivymd，我试图让 MDList 中的一个按钮转到一个页面，但是当我尝试设置 on_release 时没有任何反应。有人请帮忙。我需要能够单击退出按钮，并最好使用 python 函数将我重定向到登录屏幕，因为我还想在单击按钮后做其他事情

main.py

import kivy
from kivy.uix.widget import Widget
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.behaviors.button import ButtonBehavior
from kivymd.app import MDApp
from kivymd.theming import ThemeManager

class SignInScreen(Screen):
    pass

class HomeScreen(Screen):
    pass

class MenuScreen(Screen):
    pass

class ButtonGrid(ButtonBehavior, BoxLayout):
    pass

class AttendanceApp(MDApp):
    def build(self):
        #self.theme_cls.primary_palette = "LightBlue"
        #self.theme_cls.accent_palette = "Red"
        return HomeScreen()
    def change_theme(self, primary_palette, accent_palette):
        pass
        #theme_cls = ThemeManager()
    def signin_pressed(self, instance):
        pass

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

出勤率.kv

# Filename: Attendance.kv

#:import utils kivy.utils

#screens

<SignInScreen>
 #code

<HomeScreen>
    NavigationLayout:

        ScreenManager:

            Screen:

                BoxLayout:
                    orientation: "vertical"

                    MDToolbar:
                        title: "Home"
                        left_action_items: [["menu", lambda x: nav_menu.set_state()]]
                        elevation: 10

                    MDLabel:
                        text: "Content"
                        halign: "center"
                        
        MDNavigationDrawer:
            id: nav_menu

            MenuScreen:

ScreenManager:
    id: sm_menu

    SignInScreen:
        name: "signin"
    HomeScreen:
        name: "home"
    MenuScreen:
        name: "menu"

<MenuScreen>
        
    ScrollView:

        MDList:
            id: scroll

            OneLineAvatarIconListItem:
                id: menu_home
                text: "Home"
                elevation: 10

                IconLeftWidget:
                    icon: "home"
            
            OneLineAvatarIconListItem:
                id: menu_schedule
                text: "Schedule"
                elevation: 10

                IconLeftWidget:
                    icon: "calendar-month"
            
            OneLineAvatarIconListItem:
                id: menu_take
                text: "Take"
                elevation: 10

                IconLeftWidget:
                    icon: "account-multiple"

            OneLineAvatarIconListItem:
                id: menu_rosters
                text: "Rosters"
                elevation: 10

                IconLeftWidget:
                    icon: "clipboard-list-outline"

            OneLineAvatarIconListItem:
                id: menu_subs
                text: "Subs"
                elevation: 10

                IconLeftWidget:
                    icon: "account-multiple-outline"
            
            OneLineAvatarIconListItem:
                id: menu_help
                text: "Help"
                elevation: 10

                IconLeftWidget:
                    icon: "lightbulb-on-outline"

            OneLineAvatarIconListItem:
                id: menu_settings
                text: "Settings"
                elevation: 10

                IconLeftWidget:
                    icon: "settings-outline"        

            OneLineAvatarIconListItem:
                id: menu_signout
                text: "Sign Out"
                elevation: 10
                on_release: "signin"

                IconLeftWidget:
                    icon: "exit-to-app"

【问题讨论】：

标签： python kivy kivy-language kivymd

【解决方案1】：

您可以像这样将kv 稍微更改为Button：

        OneLineAvatarIconListItem:
            id: menu_signout
            text: "Sign Out"
            elevation: 10
            on_release: app.signout_pressed()

            IconLeftWidget:
                icon: "exit-to-app"

在你的AttendanceApp 中，添加一个方法：

def signout_pressed(self):
    print('signout pressed')
    self.root.current = 'signin'

这假定您的AttendanceApp 的root 将是ScreenManager。

【讨论】：