Kivy MDLabel 在 RecycleView 中更新数据后丢失文本

huangapple
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英文:

Kivy MDLabel in RecycleView losing text after updating data

问题

I'm having two screens, loginScreen and mainScreen. In the mainScreen I have a RecycleView of MDLabels. Initially when entering on mainScreen everything works fine, but whenever I'm refreshing the data of my RecycleView, the text of some labels keeps disappearing and appearing on scrolling.
When I use regular kivy labels instead of MDLabels, I'm not getting this strange behavior. Am I doing something wrong in the code or is this expected when using MDLabels in RecycleView?

main.py

  1. from kivymd.app import MDApp
  2. from kivy.lang import Builder
  3. from kivy.uix.screenmanager import ScreenManager
  4. from kivy.uix.screenmanager import Screen
  5. from kivymd.color_definitions import colors
  6. from kivymd.uix.boxlayout import MDBoxLayout
  7. import random
  9. class DailyService(MDBoxLayout):
  10.     pass
  12. class MainScreen(Screen):
  13.     def __init__(self, **kwargs):
  14.         super(MainScreen, self).__init__(**kwargs)
  16.     def switchButton(self):
  17.         self.manager.switchToLoginScreen()
  19. class LoginScreen(Screen):
  20.     def __init__(self, **kwargs):
  21.         super(LoginScreen, self).__init__(**kwargs)
  23.     def switchButton(self):
  24.         self.manager.switchToMainScreen()
  25.     
  26. class MyScreenManager(ScreenManager):
  27.     def __init__(self, **kwargs):
  28.         super(MyScreenManager, self).__init__(**kwargs)
  29.         
  30.     def switchToMainScreen(self):
  31.         data = []
  32.         for i in range(20):
  33.             k = random.randint(0, 9)
  34.             if k%2 == 0:
  35.                 color =  colors['BlueGray']['700']
  36.             else:
  37.                 color =  colors['Green']['700']
  38.             data.append({'day': 'DAY',
  39.                          'service': 'SERVICE',
  40.                          'bg_color':  color})
  41.         self.mainScreen.rvid.data = data
  42.         self.current = 'mainScreen'
  44.     def switchToLoginScreen(self):
  45.         self.current = 'loginScreen'
  48. class MyApp(MDApp):
  49.     def build(self):
  50.         self.theme_cls.theme_style = 'Dark'
  51.         self.theme_cls.primary_palette = 'Blue'
  52.         self.theme_cls.accent_palette = 'Amber'
  53.         return Builder.load_file('main.kv')
  55. if __name__ == '__main__':
  56.     MyApp().run()

main.kv

  1. <LoginScreen>:
  2.     name: 'loginScreen'
  4.     Button:
  5.         text: 'MAIN'
  6.         on_release: root.switchButton()
  7.         
  8. <DailyService>:
  9.     bg_color: app.theme_cls.primary_dark
  10.     day: ''
  11.     service: ''
  12.     
  13.     MDGridLayout:
  14.         rows: 2
  15.         MDLabel:
  16.             halign: 'center'
  17.             text: root.day
  19.         MDLabel:
  20.             halign: 'center'
  21.             md_bg_color: root.bg_color
  22.             text: root.service
  24. <MainScreen>:
  25.     name: 'mainScreen'
  26.     rvid: myRv
  28.     MDRecycleView:
  29.         viewclass: 'DailyService'
  30.         id: myRv
  31.         RecycleBoxLayout:
  32.             default_size: None, dp(200)
  33.             default_size_hint: 1, None
  34.             size_hint_y: None
  35.             height: self.minimum_height
  36.             orientation: 'vertical'
  37.             
  38.     Button:
  39.         pos_hint: {'x': 0.5, 'bottom': 1}
  40.         size_hint: 0.4, 0.1
  41.         text: 'LOGIN'
  42.         on_release: root.switchButton()
  44. MyScreenManager:
  45.     loginScreen: loginScreenId
  46.     mainScreen: mainScreenId
  48.     LoginScreen:
  49.         id: loginScreenId
  51.     MainScreen:
  52.         id: mainScreenId

Screenshot of the first enter on mainScreen:
Kivy MDLabel 在 RecycleView 中更新数据后丢失文本

Screenshot of the second enter on mainScreen after data update:
Kivy MDLabel 在 RecycleView 中更新数据后丢失文本

英文:

I'm having two screens, loginScreen and mainScreen. In the mainScreen I have a RecycleView of MDLabels. Initially when entering on mainScreen everything works fine, but whenever I'm refreshing the data of my RecycleView, the text of some labels keeps disappearing and appearing on scrolling.
When I use regular kivy labels instead of MDLabels, I'm not getting this strange behavior. Am I doing something wrong in the code or is this expected when using MDLabels in RecycleView?

main.py

  1. from kivymd.app import MDApp
  2. from kivy.lang import Builder
  3. from kivy.uix.screenmanager import ScreenManager
  4. from kivy.uix.screenmanager import Screen
  5. from kivymd.color_definitions import colors
  6. from kivymd.uix.boxlayout import MDBoxLayout
  7. import random
  9. class DailyService(MDBoxLayout):
  10.     pass
  12. class MainScreen(Screen):
  13.     def __init__(self, **kwargs):
  14.         super(MainScreen, self).__init__(**kwargs)
  16.     def switchButton(self):
  17.         self.manager.switchToLoginScreen()
  19. class LoginScreen(Screen):
  20.     def __init__(self, **kwargs):
  21.         super(LoginScreen, self).__init__(**kwargs)
  23.     def switchButton(self):
  24.         self.manager.switchToMainScreen()
  25.     
  26. class MyScreenManager(ScreenManager):
  27.     def __init__(self, **kwargs):
  28.         super(MyScreenManager, self).__init__(**kwargs)
  29.         #self.current = &#39;loginScreen&#39;
  30.         
  31.     def switchToMainScreen(self):
  32.         data = []
  33.         for i in range(20):
  34.             k = random.randint(0, 9)
  35.             if k%2 == 0:
  36.                 color =  colors[&#39;BlueGray&#39;][&#39;700&#39;]
  37.             else:
  38.                 color =  colors[&#39;Green&#39;][&#39;700&#39;]
  39.             data.append({&#39;day&#39;: &#39;DAY&#39;,
  40.                          &#39;service&#39;: &#39;SERVICE&#39;,
  41.                          &#39;bg_color&#39;:  color})
  42.         self.mainScreen.rvid.data = data
  43.         self.current = &#39;mainScreen&#39;
  45.     def switchToLoginScreen(self):
  46.         self.current = &#39;loginScreen&#39;
  49. class MyApp(MDApp):
  50.     def build(self):
  51.         self.theme_cls.theme_style = &#39;Dark&#39;
  52.         self.theme_cls.primary_palette = &#39;Blue&#39;
  53.         self.theme_cls.accent_palette = &#39;Amber&#39;
  54.         return Builder.load_file(&#39;main.kv&#39;)
  56. if __name__ == &#39;__main__&#39;:
  57.     MyApp().run()

main.kv

  2. &lt;LoginScreen&gt;:
  3. 	name: &#39;loginScreen&#39;
  5. 	Button:
  6. 		text: &#39;MAIN&#39;
  7. 		on_release: root.switchButton()
  8. 		
  9. &lt;DailyService&gt;:
  10. 	bg_color: app.theme_cls.primary_dark
  11.     day: &#39;&#39;
  12.     service: &#39;&#39;
  13. 	
  14.     MDGridLayout:
  15.         rows: 2
  16.         MDLabel:
  17. 			halign: &#39;center&#39;
  18.             text: root.day
  20.         MDLabel:
  21. 			halign: &#39;center&#39;
  22. 			md_bg_color: root.bg_color
  23.             text: root.service
  25. 		
  26. &lt;MainScreen&gt;:
  27. 	name: &#39;mainScreen&#39;
  28. 	rvid: myRv
  30. 	MDRecycleView:
  31. 		viewclass: &#39;DailyService&#39;
  32. 		id: myRv
  33. 		RecycleBoxLayout:
  34. 			default_size: None, dp(200)
  35. 			default_size_hint: 1, None
  36. 			size_hint_y: None
  37. 			height: self.minimum_height
  38. 			orientation: &#39;vertical&#39;
  39. 			
  40. 	Button:
  41. 		pos_hint:{&quot;x&quot;:0.5,&#39;bottom&#39;: 1}
  42. 		size_hint: 0.4, 0.1
  43. 		text: &#39;LOGIN&#39;
  44. 		on_release: root.switchButton()
  46. MyScreenManager:
  47. 	loginScreen: loginScreenId
  48. 	mainScreen: mainScreenId
  50.     LoginScreen:
  51.         id: loginScreenId
  52. 		
  53. 	MainScreen:
  54. 		id: mainScreenId

Screenshot of the first enter on mainScreen:
Kivy MDLabel 在 RecycleView 中更新数据后丢失文本

Screenshot of the second enter on mainScreen after data update:
Kivy MDLabel 在 RecycleView 中更新数据后丢失文本

答案1

得分: 0

问题似乎在使用Kivy和Kivymd的主分支时已解决。

英文:

The issue appears to be solved when using Kivy and Kivymd from the master branch.

huangapple
  • 本文由 发表于 2023年6月18日 23:56:32
  • 转载请务必保留本文链接：https://go.coder-hub.com/76501385.html
  • android
  • kivy
  • kivy-language
  • kivymd
  • python
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