kivy: изменение текста ярлыка динамически сгенерированной метки

Question

В конце, labels.text должен отображать данные датчика. Данные генерируются в отдельном процессе и передаются в киви через трубу. В настоящее время я пытаюсь реализовать очень простой минимальный пример. Тем не менее, я не получаю мою голову вокруг концепции обновления для динамически создаваемых меток:

from math import sin 

""" 
Activate the touch keyboard. It is important that this part is on top 
because the global config should be initiated first. 
""" 
from kivy.config import Config 
Config.set('kivy', 'keyboard_mode', 'multi') 

from kivy.app import App 

from kivy.clock import Clock 
# The Builder is used to define the main interface. 
from kivy.lang import Builder 

from kivy.properties import StringProperty, ObjectProperty, NumericProperty 
from kivy.uix.label import Label 
from kivy.uix.screenmanager import ScreenManager, Screen 
from kivy.uix.stacklayout import StackLayout 


import numpy as np 

class MainScreen(Screen): 
    pass 


class DataScreen(Screen): 

    def __init__(self, **kwargs): 
     layout = StackLayout() 
     super(DataScreen, self).__init__(**kwargs) 
     self.n_probes = 8 
     self.label_text = [] 
     for i in range(self.n_probes): 
      self.label_text.append(StringProperty()) 
      self.label_text[i] = str(i) 

     for i in range(self.n_probes): 
      l = Label(id='l_{}'.format(i), 
         name='l_{}'.format(i), 
         text=self.label_text[i], 
         font_size='60sp', 
         height=20, 
         width=20, 
         size_hint=(0.5, 0.2)) 
      self.ids.stack.add_widget(l) 

    def change_text(self): 
     for i in range(self.n_probes): 
      self.label_text[i] = str(2) 



Builder.load_file('phapp.kv') 

class MyApp(App): 
    """ 
    The settings App is the main app of the pHBot application. 
    It is initiated by kivy and contains the functions defining the main interface. 
    """ 


    def build(self): 
     """ 
     This function initializes the app interface and has to be called "build(self)". 
     It returns the user interface defined by the Builder. 
     """ 

     sm = ScreenManager() 
     sm.add_widget(MainScreen()) 
     sm.add_widget(DataScreen()) 
     # returns the user interface defined by the Builder 
     return sm 


if __name__ == '__main__': 
    MyApp().run() 

.kv файл:

<MainScreen>: 
    name: 'main' 
    BoxLayout: 
     orientation: 'vertical' 
     Button: 
      text: 'Go to data' 
      font_size: 40 
      on_release: app.root.current = 'data' 
     Button: 
      text: 'Exit' 
      font_size: 40 
      on_release: app.stop() 

<DataScreen>: 
    name: 'data' 
    StackLayout: 
     id: stack 
     orientation: 'lr-tb' 
    BoxLayout: 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Update' 
      font_size: 30 
      on_release: root.change_text() 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Back to main menu' 
      font_size: 30 
      on_release: app.root.current = 'main' 

Этикетки не обновляется с этой версией. Любые идеи почему?

Answer 1

Эта версия работает. Я до сих пор не понимаю, почему первый из них не сработал. Может быть, это связано с чем-то сфера? Если я старую код статично в файле .kv и файле .py (например, как в этом SO post), все работает нормально.

from math import sin 

""" 
Activate the touch keyboard. It is important that this part is on top 
because the global config should be initiated first. 
""" 
from kivy.config import Config 
Config.set('kivy', 'keyboard_mode', 'multi') 

from kivy.app import App 

from kivy.clock import Clock 
# The Builder is used to define the main interface. 
from kivy.lang import Builder 

from kivy.properties import StringProperty, ObjectProperty, NumericProperty 
from kivy.uix.label import Label 
from kivy.uix.screenmanager import ScreenManager, Screen 
from kivy.uix.stacklayout import StackLayout 


import numpy as np 

class MainScreen(Screen): 
    pass 


class DataScreen(Screen): 

    def __init__(self, **kwargs): 
     layout = StackLayout() 
     super(DataScreen, self).__init__(**kwargs) 
     self.n_probes = 8 
     self.label_text = [] 
     for i in range(self.n_probes): 
      self.label_text.append(StringProperty()) 
      self.label_text[i] = str(i) 
     self.l = [] 
     for i in range(self.n_probes): 
      self.l.append(Label(id='l_{}'.format(i), 
          text='Start {}'.format(i), 
          font_size='60sp', 
          height=20, 
          width=20, 
          size_hint=(0.5, 0.2))) 
      self.ids.stack.add_widget(self.l[i]) 

    def change_text(self): 
     for i in range(self.n_probes): 
      self.l[i].text = 'Update' + str(2) 


Builder.load_file('phapp.kv') 

class MyApp(App): 
    """ 
    The settings App is the main app of the pHBot application. 
    It is initiated by kivy and contains the functions defining the main interface. 
    """ 


    def build(self): 
     """ 
     This function initializes the app interface and has to be called "build(self)". 
     It returns the user interface defined by the Builder. 
     """ 

     sm = ScreenManager() 
     sm.add_widget(MainScreen()) 
     sm.add_widget(DataScreen()) 
     # returns the user interface defined by the Builder 
     return sm 


if __name__ == '__main__': 
    MyApp().run() 


<MainScreen>: 
    name: 'main' 
    BoxLayout: 
     orientation: 'vertical' 
     Button: 
      text: 'Go to data' 
      font_size: 40 
      on_release: app.root.current = 'data' 
     Button: 
      text: 'Exit' 
      font_size: 40 
      on_release: app.stop() 

<DataScreen>: 
    name: 'data' 
    StackLayout: 
     id: stack 
     orientation: 'lr-tb' 
    BoxLayout: 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Update' 
      font_size: 30 
      on_release: root.change_text() 
     Button: 
      size_hint: (0.5, 0.1) 
      text: 'Back to main menu' 
      font_size: 30 
      on_release: app.root.current = 'main'