当我尝试访问屏幕 ID 时，“超级”对象没有属性“__getattr__”

Question

两天以来，我一直在尝试解决这个问题。我几乎尝试了一切。我检查了我的 ids 10 次，无论它们是否是字符串。他们不是！！我将clock.schedule_one 方法用于延迟初始化，但程序未在kv 文件中定义ID。这是代码；

from kivymd.theming import ThemeManager
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.floatlayout import FloatLayout
from kivymd.uix.tab import MDTabsBase
from kivy.clock import Clock
from kivy.properties import ObjectProperty
from kivy.app import App
Window.size = (300 , 400)


class Screen1(Screen):
    pass
class Screen2(Screen):
    pass
class Manager(ScreenManager):
    pass


Builder.load_string("""

<Manager>:
  
    Screen1:
        
    Screen2:
        
<Screen1>:
    name:"scr1"
    
    BoxLayout:
        
        orientation: 'vertical'
        MDToolbar:
            
            title:"ahmet"
        MDTabs:
            
            tab_display_mode: "text"
            on_tab_switch:app._press
            
            
            MDTabsBase:
                id:hasta
                text: "hasta"
                
                   
            MDTabsBase:
                id:doktor
                text: "doktor"

            

    FloatLayout:
        
                   
        MDRoundFlatIconButton:
            on_press:app._doThis
            text:"submit"
            pos_hint:{"x":0.3,"top":0.7}
            
    FloatLayout:
        orientation: 'vertical'
        MDTextFieldRound:
            id:email
            icon_left: "email"
            hint_text: "email"
            pos_hint:{"x":0.35,"top":0.5}
            size_hint:0.3,0.05
        MDTextFieldRound:
            id:password
            icon_left: "password"
            hint_text: "password"
            pos_hint:{"x":0.35,"top":0.4}
            size_hint:0.3,0.05
        MDLabel:
            multinline:True
            text:
                "label"
            pos_hint:{"x":0.2,"top":0.35}
            size_hint:0.6,0.3
            font_style:"H6"
            font_size:15
            theme_text_color: "Custom"
            text_color: 0, 0, 1, 1
        

<Screen2>:
    name:"scr2"
    
    BoxLayout:
        
        orientation: 'vertical'
        MDToolbar:
            text:"ahmet"
        MDTabs:
            
            on_tab_switch:app._press
            MDTabsBase:
                id:hasta
                text: "hasta"
                
                   
            MDTabsBase:
                id:doktor
                text: "doktor"
    FloatLayout:
        orientation: 'horizontal'
        MDRoundFlatIconButton:
            on_press:app._doThis
            text:"submit"
            pos_hint:{"x":0.3,"top":0.7}
            
        
           
    FloatLayout:
        orientation: 'vertical'
        MDTextFieldRound:
            id:email
            icon_left: "email"
            hint_text: "email"
            pos_hint:{"x":0.35,"top":0.5}
            size_hint:0.3,0.05
        MDTextFieldRound:
            id:password
            icon_left: "password"
            hint_text: "password"
            pos_hint:{"x":0.35,"top":0.4}
            size_hint:0.3,0.05
        MDLabel:
            multiline:True
            text:
                "label"
            pos_hint:{"x":0.2,"top":0.35}
            size_hint:0.6,0.3
            font_style:"H6"
            font_size:15   
            theme_text_color: "Custom"
            text_color: 0, 0, 1, 1            
""")




class DemoApp(MDApp):
    
    def build(self):
        Clock.schedule_once(self._press,2)
        Clock.schedule_once(self._doThis,2)
        return Manager()
    
    def _press(self,*dt):
        self.root.ids.hasta.text
        
     
    def _doThis(self,*dt):
        self.root.ids.hasta.text
        
   
DemoApp().run()

这是错误信息；

KeyError: 'hasta'


During handling of the above exception, another exception occurred:

Traceback (most recent call last):

  File "C:\Users\Melikşah GÜRCÜ\Desktop\md.py", line 162, in <module>
    DemoApp().run()

  File "C:\python\lib\site-packages\kivy\app.py", line 855, in run
    runTouchApp()

  File "C:\python\lib\site-packages\kivy\base.py", line 504, in runTouchApp
    EventLoop.window.mainloop()

  File "C:\python\lib\site-packages\kivy\core\window\window_sdl2.py", line 747, in mainloop
    self._mainloop()

  File "C:\python\lib\site-packages\kivy\core\window\window_sdl2.py", line 479, in _mainloop
    EventLoop.idle()

  File "C:\python\lib\site-packages\kivy\base.py", line 339, in idle
    Clock.tick()

  File "C:\python\lib\site-packages\kivy\clock.py", line 591, in tick
    self._process_events()

  File "kivy\_clock.pyx", line 384, in kivy._clock.CyClockBase._process_events

  File "kivy\_clock.pyx", line 414, in kivy._clock.CyClockBase._process_events

  File "kivy\_clock.pyx", line 412, in kivy._clock.CyClockBase._process_events

  File "kivy\_clock.pyx", line 167, in kivy._clock.ClockEvent.tick

  File "C:\Users\Melikşah GÜRCÜ\Desktop\md.py", line 155, in _press
    self.root.ids.hasta.text

  File "kivy\properties.pyx", line 863, in kivy.properties.ObservableDict.__getattr__

AttributeError: 'super' object has no attribute '__getattr__'

Answer 1

class DemoApp(MDApp):

    def _press(self, *dt):
        print(self.root.get_screen("scr2").ids.hasta.text)

    def _doThis(self, *dt):
        print(self.root.get_screen("scr2").ids.hasta.text)