【发布时间】：2019-06-17 17:00:23
【问题描述】：
我的 kv 代码有问题。我想用几个NavigationDrawerIconButtons 创建一个MDNavigationDrawer。该窗口出现，但是当我单击 MDToolbar 时，程序崩溃并显示此错误消息。
Traceback (most recent call last):
File "C:/Users/path/to/my/file/main.py", line 189, in <module>
KivyGUI().run()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\app.py", line 855, in run
runTouchApp()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\base.py", line 504, in runTouchApp
EventLoop.window.mainloop()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\core\window\window_sdl2.py", line 746, in mainloop
self._mainloop()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\core\window\window_sdl2.py", line 478, in _mainloop
EventLoop.idle()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\base.py", line 342, in idle
self.dispatch_input()
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\base.py", line 327, in dispatch_input
post_dispatch_input(*pop(0))
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\base.py", line 293, in post_dispatch_input
wid.dispatch('on_touch_up', me)
File "kivy\_event.pyx", line 707, in kivy._event.EventDispatcher.dispatch
File "C:\Users\uname\Anaconda3\lib\site-packages\kivymd\ripplebehavior.py", line 84, in on_touch_up
return super().on_touch_up(touch)
File "C:\Users\uname\Anaconda3\lib\site-packages\kivymd\button.py", line 480, in on_touch_up
return super().on_touch_up(touch)
File "C:\Users\uname\Anaconda3\lib\site-packages\kivy\uix\behaviors\button.py", line 179, in on_touch_up
self.dispatch('on_release')
File "kivy\_event.pyx", line 703, in kivy._event.EventDispatcher.dispatch
File "kivy\_event.pyx", line 1214, in kivy._event.EventObservers.dispatch
File "kivy\_event.pyx", line 1138, in kivy._event.EventObservers._dispatch
File "C:\Users\path\to\my\file\design.kv", line 59, in <lambda>
left_action_items: [['dots-vertical', lambda x: root.toggle_nav_drawer()]]
File "kivy\weakproxy.pyx", line 32, in kivy.weakproxy.WeakProxy.__getattr__
AttributeError: 'LayoutPy' object has no attribute 'toggle_nav_drawer'
我从一个单独的文件中导入 kv 代码。
#:kivy 1.11.0
#:import MDNavigationDrawer kivymd.navigationdrawer.MDNavigationDrawer
#:import NavigationLayout kivymd.navigationdrawer.NavigationLayout
#:import NavigationDrawerDivider kivymd.navigationdrawer.NavigationDrawerDivider
#:import NavigationDrawerToolbar kivymd.navigationdrawer.NavigationDrawerToolbar
#:import NavigationDrawerSubheader kivymd.navigationdrawer.NavigationDrawerSubheader
#:import MDToolbar kivymd.toolbar.MDToolbar
<ContentNavigationDrawer@MDNavigationDrawer>:
drawer_logo: 'src/LinguIcon.png'
NavigationDrawerSubheader:
text: "Menu:"
<LayoutPy>:
orientation: 'vertical'
scr_mngr: scr_mngr
NavigationLayout:
id: nav_layout
ContentNavigationDrawer:
id: nav_drawer
name: 'nav_drawer'
NavigationDrawerToolbar:
title: 'Options'
NavigationDrawerIconButton:
icon: 'settings'
text: 'Select Language'
on_release: root.open2ndScreen('screen_card')
NavigationDrawerIconButton:
icon: 'close'
text: 'Exit'
on_release: root.exit()
NavigationDrawerIconButton:
icon: 'face'
text: 'Contact the developer'
on_release: root.sendDevHint()
BoxLayout:
orientation: 'vertical'
MDToolbar:
id: toolbar
title: 'Menu'
md_bg_color: app.theme_cls.primary_color
background_palette: 'Primary'
background_hue: '500'
left_action_items: [['dots-vertical', lambda x: root.toggle_nav_drawer()]]
Widget:
ScreenManager:
id: scr_mngr
screen_main: screen_main
Screen:
id: screen_main
name: 'screen_main'
input_words: input_words
lbl: lbl
btn: btn
FloatLayout:
### A few widgets ###
Screen:
id: screen_card
name: 'screen_card'
FloatLayout:
### A few widgets ###
Python 代码：
import sys
import kivy
from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.core.window import Window
from kivymd.theming import ThemeManager
from kivymd.label import MDLabel
from kivymd.textfields import MDTextField, MDTextFieldClear, MDTextFieldRect, MDTextFieldRound
from kivy.lang import Builder
from kivymd.navigationdrawer import MDNavigationDrawer, NavigationDrawerIconButton, NavigationLayout
from kivy.properties import ObjectProperty
from kivymd.toast import toast
kivy.require('1.11.0')
class LayoutPy(FloatLayout):
def __init__(self, **kwargs):
super(LayoutPy, self).__init__(**kwargs)
self.scr_mngr = ObjectProperty(None)
self.build_nav_btns()
def callback(self, instance, value):
toast("Pressed item menu %d" % value)
def exit(self):
sys.exit(1)
def build_nav_btns(self):
btns = ["Select Language", "Contact the developer", "Exit"]
for count, btn in enumerate(btns):
if count == 1:
self.ids.nav_drawer.add_widget(
NavigationDrawerIconButton(
icon='settings', text=btn,
on_release=lambda x, btn: self.callback(x, btn)))
elif count == 2:
self.ids.nav_drawer.add_widget(
NavigationDrawerIconButton(
icon='face', text=btn,
on_release=lambda x, btn: self.callback(x, btn)))
elif count == 3:
self.ids.nav_drawer.add_widget(
NavigationDrawerIconButton(
icon='close', text=btn,
on_release=lambda x: self.exit()))
Builder.load_file("design.kv")
class KivyGUI(App):
theme_cls = ThemeManager()
theme_cls.primary_palette = ("Teal")
title = ("App")
def build(self):
c = LayoutPy()
return c
if __name__ == "__main__":
KivyGUI().run()
我删减了很多 Python 代码，这样你就更清楚了。我不认为这是模块本身的问题，因为KivyMD example code 对我来说很好（这也是我运行它时解决方案的样子）。我认为问题在于我的 LayoutPy 类继承自 FloatLayout 没有 toggle_nav_drawer 对象...但我现在不知道如何在现有代码中实现合适的解决方案（我正在尝试 2 天现在）。如果您需要完整代码（在添加NavigationDrawer 之前几乎一切正常），您可以查看here。
非常感谢！
【问题讨论】：
标签： python python-3.x kivy navigationbar kivy-language