我添加了KivyMD底部导航到我的应用程序，我可以用图标切换屏幕，但问题是切换回包含底部导航的屏幕(假设我们在任何包含工具栏和底部导航的屏幕中，我们使用工具栏切换到一个完全不同的屏幕，我无法回到上一个屏幕，甚至无法导航到任何包含底部导航和工具栏的屏幕，它返回一个空白的屏幕)。
尽管命名屏幕，所以我的问题是;1. 我引用(命名)的底部导航项错误，如果是，请我应该怎么改变。
如果我有什么遗漏了，请告诉我。谢谢。
我的main.py文件
from kivymd.app import MDApp
from kivy.uix.screenmanager import Screen, ScreenManager, NoTransition
from kivy.core.window import Window
Window.size = (300, 530)
class MainScreen(Screen):
pass
class IntroScreen(Screen):
pass
class WaysScreen(Screen):
pass
class To_DoScreen(Screen):
pass
class SuccessScreen(Screen):
pass
class GoalsScreen(Screen):
pass
class BellaBaron(Screen):
pass
class SearchScreen(Screen):
pass
class MenuScreen(Screen):
pass
class CalendarScreen(Screen):
pass
class ExtraScreen(Screen):
pass
class ArchiveScreen(Screen):
pass
class Contact_InfoScreen(Screen):
pass
class TenThousandApp(MDApp):
def build(self):
self.theme_cls.primary_palette = 'Green'
self.theme_cls.primary_hue = '200'
# self.theme_cls.theme_style = 'Light'
self.sm = ScreenManager(transition=NoTransition())
self.sm.add_widget(MainScreen(name="main_screen"))
self.sm.add_widget(IntroScreen(name="intro_screen"))
self.sm.add_widget(WaysScreen(name="ways_screen"))
self.sm.add_widget(To_DoScreen(name="to_do_screen"))
self.sm.add_widget(SuccessScreen(name="success_screen"))
self.sm.add_widget(GoalsScreen(name="goals_screen"))
self.sm.add_widget(BellaBaron(name="bella_baron"))
self.sm.add_widget(SearchScreen(name="search_screen"))
self.sm.add_widget(MenuScreen(name="menu_screen"))
self.sm.add_widget(CalendarScreen(name="calendar_screen"))
self.sm.add_widget(ExtraScreen(name="extra_screen"))
self.sm.add_widget(ArchiveScreen(name="archive_screen"))
self.sm.add_widget(Contact_InfoScreen(name="contact_info_screen"))
return self.sm
def change_screen(self, screen):
self.sm.current = screen
TenThousandApp().run()
这是我的。kv文件
# ScreenManager:
#start of imagelist
<MyTile@SmartTileWithLabel>
size_hint_y: None
height: "240dp"
<MainScreen>:
MDBottomNavigation:
# panel_color: .2, .2, .2, 1
MDBottomNavigationItem:
name: "intro_screen"
text: 'home'
icon: 'home'
MDBoxLayout:
orientation: 'vertical'
# md_bg_color: app.theme_cls.bg_dark
MDToolbar:
id: intro_screen_toolbar
title: '[font=Gabriola][size=40][color=#FD0101]First[/color][/size][size=28]project[/size][/font]'
right_action_items: [["calendar-month", lambda x: app.change_screen('to_do_screen')]] #links to to-do listss screen
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
size_hint: None, None
size: "280dp", "360dp"
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - intro_screen_toolbar.height - dp(55)
y: root.height - intro_screen_toolbar.height - dp(50)
elevation: "8dp"
orientation: 'vertical'
radius: 15
ScrollView:
MDLabel:
markup: True
size_hint_y: None
size: self.texture_size
text:
"""[b][i]“Your time is limited, so don’t waste it living someone else’s life. Don’t be trapped by dogma – which is living with the results of other people’s thinking. Don’t let the noise of other’s opinions drown out your own inner voice. And most important, have the courage to follow your heart and intuition. They somehow already know what you truly want to become. Everything else is secondary.”[/i][/b]
– Steve Jobs"""
MDBottomNavigationItem:
name: "success_screen"
text: 'home'
icon: 'account-group'
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: success_screen_toolbar
title: "Success Stories"
right_action_items: [["progress-clock", lambda x: app.change_screen('goals_screen')]] #links to goals and how screen
elevation: "8dp"
ScrollView:
MDGridLayout:
cols: 1
adaptive_height: True
padding: dp(4), dp(4)
spacing: dp(4)
MyTile:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
text: "[size=26]Cat 1[/size]\n[size=14]cat-1.jpg[/size]"
on_release:
app.root.current = 'bella_baron'
MyTile:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
text: "[size=26]Cat 2[/size]\n[size=14]cat-2.jpg[/size]"
tile_text_color: app.theme_cls.accent_color
MyTile:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
text: "[size=26][color=#ffffff]Cat 3[/color][/size]\n[size=14]cat-3.jpg[/size]"
tile_text_color: app.theme_cls.accent_color
MDBottomNavigationItem:
name: "search_screen"
text: 'search'
icon: 'magnify'
FloatLayout:
MDTextField:
mode: 'fill'
hint_text: "Search"
pos_hint: {"center_x": .5,"center_y": .9}
size_hint_x: None
width: 280
MDBottomNavigationItem:
name: "menu_screen"
text: 'menu'
icon: 'menu'
BoxLayout:
orientation: "vertical"
md_bg_color: (240/255, 240/255, 240/255, 1)
MDToolbar:
id: menu_screen_toolbar
title: "Tools"
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
size_hint: None, None
size: "280dp", "360dp"
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - menu_screen_toolbar.height - dp(55)
y: root.height - menu_screen_toolbar.height - dp(50)
elevation: 8
orientation: 'vertical'
radius: 15
ScrollView:
MDList:
OneLineIconListItem:
text: "Calendar"
on_release:
app.root.current = "calendar_screen"
IconLeftWidget:
icon: "calendar-month"
OneLineIconListItem:
text: "Extra"
on_release:
app.root.current = "extra_screen"
IconLeftWidget:
icon: "notebook-multiple"
OneLineIconListItem:
text: "Archive"
on_release:
app.root.current = "archive_screen"
IconLeftWidget:
icon: "archive"
OneLineIconListItem:
text: "contact Us"
on_release:
app.root.current = "contact_info_screen"
IconLeftWidget:
icon: "email-mark-as-unread"
<WaysScreen>
name: "ways_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: ways_screen_toolbar
title: "How-tos"
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('intro_screen')]] # to add more list
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('intro_screen')]]
elevation: "8dp"
ScrollView:
MDGridLayout:
cols: 1
adaptive_height: True
spacing: 10
padding: 10
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
Image:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello dear'
ScrollView:
MDLabel:
size_hint_y: None
size: self.texture_size
# halign: 'center'
text:
"""This screens contains a MDcard which where the image is placed, and a MDLabel and neccessary widgets used to tell the success story, under the MDCard."""
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello boss'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello goodness'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello hi'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello yes?'
<To_DoScreen>
name: "to_do_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: to_do_screen_toolbar
title: 'To-Do-List'
right_action_items: [['plus', lambda x: x]] # to add more list
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('intro_screen')]]
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
elevation: 8
radius: 15
size_hint: None, None
size: '280', '360'
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - to_do_screen_toolbar.height + dp(10)
y: root.height - to_do_screen_toolbar.height - dp(20)
<GoalsScreen>
name: 'goals_screen'
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: goals_screen_toolbar
title: 'Goals'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('success_screen')]]
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
size_hint: None, None
size: "280dp", "360dp"
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - goals_screen_toolbar.height + dp(10)
y: root.height - goals_screen_toolbar.height - dp(20)
elevation: "8dp"
orientation: 'vertical'
radius: 15
<BellaBaron>
name: 'bella_baron'
BoxLayout:
orientation: 'vertical'
md_bg_color: (240/255, 240/255, 240/255, 1)
MDToolbar:
id: bella_baron_toolbar
title: "Bella Baron"
left_action_items: [["keyboard-backspace", lambda x: app.change_screen('success_screen')]]
right_action_items: [["progress-check", lambda x: app.change_screen('goals_screen')]] #link to progress screen
elevation: "8dp"
ScrollView:
MDGridLayout:
cols: 1
adaptive_height: True
spacing: 10
padding: 10
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
Image:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello dear'
ScrollView:
MDLabel:
size_hint_y: None
size: self.texture_size
# halign: 'center'
text:
"""This screens contains a MDcard which where the image is placed, and a MDLabel and neccessary widgets used to tell the success story, under the MDCard."""
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello boss'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello goodness'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello hi'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello yes?'
<CalendarScreen>
name: "calendar_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: calendar_screen_toolbar
title: 'Calendar'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('menu_screen')]]
right_action_items: [['calendar', lambda x: x]] # on press returns today's date
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
elevation: 8
radius: 15
size_hint: None, None
size: '280', '360'
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - calendar_screen_toolbar.height + dp(10)
y: root.height - calendar_screen_toolbar.height - dp(20)
# I will remove this screen if there is no need for it.
<ExtraScreen>
name: "extra_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: extra_screen_toolbar
title: 'Extra'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('menu_screen')]]
elevation: "8dp"
ScrollView:
MDGridLayout:
cols: 1
adaptive_height: True
spacing: 10
padding: 10
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
Image:
source: "C:/Users/HP USER/Downloads/bella_baron.jpg"
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello dear'
ScrollView:
MDLabel:
size_hint_y: None
size: self.texture_size
# halign: 'center'
text:
"""This screens contains a MDcard which where the image is placed, and a MDLabel and neccessary widgets used to tell the success story, under the MDCard."""
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello boss'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello goodness'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello hi'
MDCard:
size_hint: None, None
size: "280dp", "130dp"
radius: 15
caption: 'Hello yes?'
<ArchiveScreen>
name: "archive_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: archive_screen_toolbar
title: 'Archive'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('menu_screen')]]
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
elevation: 8
radius: 15
size_hint: None, None
size: '280', '360'
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - archive_screen_toolbar.height + dp(10)
y: root.height - archive_screen_toolbar.height - dp(20)
<Contact_InfoScreen>
name: "contact_info_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: contact_info_screen_toolbar
title: 'Contact Info'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen('menu_screen')]]
elevation: "8dp"
MDCard:
orientation: 'vertical'
padding: 16
elevation: 8
radius: 15
size_hint: None, None
size: '280', '360'
pos_hint: {"center_x": .5, "center_y": .6}
height: root.height - contact_info_screen_toolbar.height + dp(10)
y: root.height - contact_info_screen_toolbar.height - dp(20)
ScrollView:
MDLabel:
size_hint_y: None
size: self.texture_size
text:
"""feel free to reach us @"""
要在MDBottomNavigation中更改为不同的MDBottomNavigationItem，应使用MDBottomNavigation的switch_tab()方法。您可以在TenThousandApp类中添加一个方法:
def change_screen_item(self, nav_item):
# change to the MainScreen and switch to the spcified MDBottomNavigationItem
s = self.sm.get_screen('main_screen')
s.ids.bottom_nav.switch_tab(nav_item)
self.sm.current = 'main_screen'
在kv中，您必须为MDBottomNavigation添加id:
<MainScreen>:
MDBottomNavigation:
id: bottom_nav
# panel_color: .2, .2, .2, 1
使用id访问MDBottomNavigation实例。
然后在kv中，您可以使用change_screen_item()切换到MainScreen并切换到指定的MDBottomNavigationItem，如下所示:
<CalendarScreen>
name: "calendar_screen"
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: calendar_screen_toolbar
title: 'Calendar'
left_action_items: [['keyboard-backspace', lambda x: app.change_screen_item('intro_screen')]]
right_action_items: [['calendar', lambda x: x]] # on press returns today's date
elevation: "8dp"
以上代码将切换到MainScreen的intro_screen项。