[英]Screen manager AttributeError: 'super' object has no attribute '__getattr__'
[英]screen manager (AttributeError: 'super' object has no attribute '__getattr__')
我对Kivy编程相当陌生,需要在项目中使用它。 我遇到的问题是,每当尝试使用屏幕管理器来更改屏幕时,都会不断出现以下错误。
AttributeError:'super'对象没有属性' getattr '
如果有人可以解释如何解决该错误,但同时也可以说明引起错误的原因? 任何帮助都非常有用
主要代码:
import kivy
import webbrowser
import MSQLHandler
kivy.require('1.10.0')
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Label
from kivy.uix.widget import Widget
from kivy.uix.listview import ListItemButton
from kivy.properties import ObjectProperty
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, CardTransition
class Login(Screen):
class kivy_screen_manager(ScreenManager):
pass
teacher_connect_image = ObjectProperty()
username_text_input = ObjectProperty()
password_text_input = ObjectProperty()
def LoginButton(self):
MSQLHandler.LoginSystem(self.username_text_input.text, self.password_text_input.text, 0)
def changeScreen(self, next_screen):
self.manager.current = next_screen
class MainKivyFrameApp(App):
def build(self):
return Login()
mainFrame = MainKivyFrameApp()
mainFrame.run()
`
.Kv文件
#: import main NewProject
#: import CardTransition kivy.uix.screenmanager.CardTransition
ScreenManager:
Login:
id: kivy_screen_manager
name: "Login"
LogedInScreen:
id: LogedInScreen
name: "LogedInScreen"
<Login@Screen>:
id: kivy_screen_manager
name: "Login"
teacher_connect_image: logo_image
username_text_input: username
password_text_input: password
teahcerId_text_input: teacherId
name: "LoginMain"
BoxLayout:
padding: 10
spacing: 10
orientation: "vertical"
Image:
source: 'ApplicationMainLogo.png'
id: logo_image
Label:
text: "Teacher ID"
TextInput:
font_size: root.height / 20
id: teacherId
Label:
text: "Username"
TextInput:
font_size: root.height / 20
id: username
Label:
text: "Password"
TextInput:
font_size: root.height / 20
id: password
Button:
text: "Login"
on_release: app.root.changeScreen("LogedInScreen")
<LogedInScreen@Screen>:
id: LogedInScreen
name: "LogedInScreen"
padding: 10
spacing: 10
orientation: "vertical"
Button:
text: "Back Home?"
`
完整的错误消息:
Traceback (most recent call last):
File "C:/Users/XOmar/Desktop/MMSA - Multi Media School Access/NewProject.py", line 39, in <module>
mainFrame.run()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\app.py", line 801, in run
self.load_kv(filename=self.kv_file)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\app.py", line 598, in load_kv
root = Builder.load_file(rfilename)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\builder.py", line 301, in load_file
return self.load_string(data, **kwargs)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\builder.py", line 350, in load_string
parser = Parser(content=string, filename=fn)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\parser.py", line 392, in __init__
self.parse(content)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\parser.py", line 498, in parse
self.execute_directives()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\parser.py", line 462, in execute_directives
mod = __import__(package)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\NewProject.py", line 39, in <module>
mainFrame.run()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\app.py", line 828, in run
runTouchApp()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\base.py", line 504, in runTouchApp
EventLoop.window.mainloop()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\core\window\window_sdl2.py", line 663, in mainloop
self._mainloop()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\core\window\window_sdl2.py", line 405, in _mainloop
EventLoop.idle()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\base.py", line 342, in idle
self.dispatch_input()
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\base.py", line 327, in dispatch_input
post_dispatch_input(*pop(0))
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\base.py", line 293, in post_dispatch_input
wid.dispatch('on_touch_up', me)
File "kivy\_event.pyx", line 718, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:8191)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\uix\behaviors\button.py", line 179, in on_touch_up
self.dispatch('on_release')
File "kivy\_event.pyx", line 714, in kivy._event.EventDispatcher.dispatch (kivy\_event.c:8146)
File "kivy\_event.pyx", line 1225, in kivy._event.EventObservers.dispatch (kivy\_event.c:14035)
File "kivy\_event.pyx", line 1109, in kivy._event.EventObservers._dispatch (kivy\_event.c:12816)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\venv\lib\site-packages\kivy\lang\builder.py", line 64, in custom_callback
exec(__kvlang__.co_value, idmap)
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\mainkivyframe.kv", line 51, in <module>
on_release: app.root.changeScreen("LogedInScreen")
File "C:\Users\XOmar\Desktop\MMSA - Multi Media School Access\NewProject.py", line 30, in changeScreen
self.manager.current = next_screen
AttributeError: 'NoneType' object has no attribute 'current'
'
错误消息是正确的:
Traceback (most recent call last):
File "kivy\properties.pyx", line 836, in kivy.properties.ObservableDict.__getattr__ (kivy\properties.c:12509)
KeyError: 'kivy_screen_manager'
表示kivy_screen_manager
不是ids
一部分,这些id存储在字典中。
只能通过id来访问Login的子级,如果摘要中看到.kv,我们将显示以下内容,并且显然kivy_screen_manager
不在Login下。
<Login@Screen>:
...
name: "LoginMain"
BoxLayout:
...
Label:
...
TextInput:
...
id: teacherId
Label:
...
TextInput:
...
id: username
Label:
...
TextInput:
...
id: password
Button:
...
如果要从屏幕访问ScreenManager
,则必须使用manager
属性,在这种情况下,它会发生变化:
self.ids.kivy_screen_manager.current = "LogedInScreen"
至
self.manager.current = "LogedInScreen"
更新:
问题在于,root用户是Login,而不是ScreenManager
,并且在root之上没有任何内容,因此即使您已声明ScreenManager
也不存在。
假设.kv
文件名为design.kv
则必须修改以下部分:
design.kv
....
<Login@Screen>:
...
Button:
text: "Login"
on_release: root.changeScreen("LogedInScreen")
...
并使用Builder加载.kv:
from kivy.lang import Builder
....
class MainKivyFrameApp(App):
def build(self):
root = Builder.load_file("design.kv")
return root
...
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