我是Kivy的新手，试图为我的覆盆子建造小OSD。
我的.kv文件看起来像这样：
BoxLayout:
orientation: 'vertical'
Label:
text_size: self.size
text: 'OSD'
font_size: 50
bold: True
halign: 'center'
valign: 'top'
size_hint: 1, .3
GridLayout:
cols: 2
Label:
text_size: self.size
text: 'Total entries in DB: '
font_size: 30
bold: False
halign: 'left'
size_hint: 1, .1
Label:
id: total_db
text_size: self.size
text: '366 000 '
font_size: 30
bold: True
color: 0, 1, 0, 1
halign: 'center'
size_hint: 1, .1
Label:
text_size: self.size
text: 'Info 1: '
font_size: 30
bold: False
halign: 'left'
size_hint: 1, .1
Label:
id: marked_update
text_size: self.size
text: '1328 '
color: 1, 0, 0, 1
font_size: 30
bold: True
halign: 'center'
size_hint: 1, .1
Label:
text_size: self.size
text: 'Activity'
font_size: 50
bold: True
halign: 'center'
valign: 'top'
size_hint: 1, .3
Label:
text: ''
font_size: 10
halign: 'center'
valign: 'top'
size_hint: 1, .08
GridLayout:
cols: 4
Button:
text: 'DS 01'
font_size: 25
background_color: 1, 0, 0, 1
Button:
text: 'DS 02'
font_size: 25
background_color: 0, 1, 0, 1
Button:
text: 'DS 03'
font_size: 25
background_color: 0, 1, 0, 1
Button:
text: 'DS 04'
font_size: 25
background_color: 0, 1, 0, 1
这会产生我想要的外观。我想定期更新带有ID的两个标签文本，并在以后提取的值...但是我什至无法从Python更新它们，看起来像这样：
import kivy
kivy.require('1.10.1')
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.clock import Clock
class BoxLayout(BoxLayout):
def __init__(self, **kwargs):
super(BoxLayout, self).__init__(**kwargs)
Clock.schedule_once(self.update_txt, 0)
def update_txt(self, *args):
self.label.ids.marked_update.txt='updated from python'
class osdApp(App):
def build(self):
self.title = 'OSD'
return BoxLayout()
if __name__ == '__main__':
osdApp().run()
我正在考虑启动调用update_txt函数的时钟，并且可能会更改值，但是我一直在遇到ID不存在的错误...等等，我是针对目标的编程的新手，我可以't这个简单的东西
对于任何在搜索Kivy中的on_load事件中找到自己的问题的人，我找到了一个解决方案。Kivy中的App类提供了一个成员函数on_start(self(，一旦应用程序完成构建和加载，该函数就被称为。我们只需要添加应用程序在其体内加载后要调用的功能即可。例如：
class MyApp(App):
def build(self):
...
def on_start(self):
super().on_start(self)
my_f()
update_texts()一些观察：
-
作为注释@eyllanesc，您不应将您的子类命名为其继承的类。
-
self.label.ids.marked_update.txt不正确。它应该是self.ids.marked_update.text。 -
将您的根小部件声明为KV规则。
您的代码可能是：
-
main.py
import kivy kivy.require('1.10.0') from kivy.app import App from kivy.uix.boxlayout import BoxLayout from kivy.clock import Clock class RootWidget(BoxLayout): def __init__(self, **kwargs): super(BoxLayout, self).__init__(**kwargs) Clock.schedule_once(self.update_txt, 0.1) def update_txt(self, *args): self.ids.marked_update.text = 'updated from python' class OsdApp(App): def build(self): self.title = 'OSD' return RootWidget() if __name__ == '__main__': OsdApp().run() -
OSD.KV：
<RootWidget>: orientation: 'vertical' Label: text_size: self.size text: 'OSD' font_size: 50 bold: True halign: 'center' valign: 'top' size_hint: 1, .3 GridLayout: cols: 2 Label: text_size: self.size text: 'Total entries in DB: ' font_size: 30 bold: False halign: 'left' size_hint: 1, .1 Label: id: total_db text_size: self.size text: '366 000 ' font_size: 30 bold: True color: 0, 1, 0, 1 halign: 'center' size_hint: 1, .1 Label: text_size: self.size text: 'Info 1: ' font_size: 30 bold: False halign: 'left' size_hint: 1, .1 Label: id: marked_update text_size: self.size text: '1328 ' color: 1, 0, 0, 1 font_size: 30 bold: True halign: 'center' size_hint: 1, .1 Label: text_size: self.size text: 'Activity' font_size: 50 bold: True halign: 'center' valign: 'top' size_hint: 1, .3 Label: text: '' font_size: 10 halign: 'center' valign: 'top' size_hint: 1, .08 GridLayout: cols: 4 Button: text: 'DS 01' font_size: 25 background_color: 1, 0, 0, 1 Button: text: 'DS 02' font_size: 25 background_color: 0, 1, 0, 1 Button: text: 'DS 03' font_size: 25 background_color: 0, 1, 0, 1 Button: text: 'DS 04' font_size: 25 background_color: 0, 1, 0, 1
但是，我建议使用Kivy属性代替IDS：
-
main.py ：
import kivy kivy.require('1.10.0') from kivy.app import App from kivy.uix.boxlayout import BoxLayout from kivy.properties import StringProperty class RootWidget(BoxLayout): marked_text = StringProperty() def __init__(self, **kwargs): super(BoxLayout, self).__init__(**kwargs) self.update_txt() def update_txt(self, *args): self.marked_text ='updated from python' class OsdApp(App): def build(self): self.title = 'OSD' return RootWidget() if __name__ == '__main__': OsdApp().run() -
OSD.KV：
<RootWidget>: id: root_layout orientation: 'vertical' marked_text: '1328 ' Label: text_size: self.size text: 'OSD' font_size: 50 bold: True halign: 'center' valign: 'top' size_hint: 1, .3 GridLayout: cols: 2 Label: text_size: self.size text: 'Total entries in DB: ' font_size: 30 bold: False halign: 'left' size_hint: 1, .1 Label: id: total_db text_size: self.size text: '366 000 ' font_size: 30 bold: True color: 0, 1, 0, 1 halign: 'center' size_hint: 1, .1 Label: text_size: self.size text: 'Info 1: ' font_size: 30 bold: False halign: 'left' size_hint: 1, .1 Label: id: marked_update text_size: self.size text: root_layout.marked_text color: 1, 0, 0, 1 font_size: 30 bold: True halign: 'center' size_hint: 1, .1 Label: text_size: self.size text: 'Activity' font_size: 50 bold: True halign: 'center' valign: 'top' size_hint: 1, .3 Label: text: '' font_size: 10 halign: 'center' valign: 'top' size_hint: 1, .08 GridLayout: cols: 4 Button: text: 'DS 01' font_size: 25 background_color: 1, 0, 0, 1 Button: text: 'DS 02' font_size: 25 background_color: 0, 1, 0, 1 Button: text: 'DS 03' font_size: 25 background_color: 0, 1, 0, 1 Button: text: 'DS 04' font_size: 25 background_color: 0, 1, 0, 1