python [Kivy]从Slider更新标签

Posted 2021-05-09

from kivy.app           import App
from kivy.lang          import Builder
from kivy.uix.boxlayout import BoxLayout


Builder.load_string('''
<MyLayout>:
	orientation: "vertical"
	padding:     50, 50, 50, 50

	Label:
		id: label

	Slider:
		id: slider
''')

class MyLayout(BoxLayout):

	def on_parent(self, widget, parent):
		self.ids.slider.bind(
			on_touch_down=self.update_label,
			on_touch_move=self.update_label,
		)
		self.update_label(self.ids.slider, None)

	def update_label(self, instance, touch):
		self.ids.label.text = str(self.ids.slider.value)


class DemoApp(App):
	def build(self):
		return( MyLayout() )

if __name__ == "__main__":
	DemoApp().run()