单击按钮时如何更改标签的新背景颜色？

Question

单击按钮时如何更改按钮的颜色？

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import StringProperty
class TestWidget(Widget):
    back_color = StringProperty('')
    back_color = (0.4, 0.4, 0.4, 1)

    def __init__(self, **kwargs):
        super(TestWidget, self).__init__(**kwargs)
    def crick(self):
        self.back_color = (175/255,238/255,238/255,1)
        
class TestApp(App):
    def __init__(self, **kwargs):
        super(TestApp, self).__init__(**kwargs)
        
if __name__ == '__main__':
    TestApp().run()

TestWidget:

<TestWidget>:
    BoxLayout:
        Label:
            canvas.before:
                Color:
                    rgba: root.back_color
                Rectangle:
                    pos: self.pos
                    size: self.size
            id: label1
            text: "Color"

        Button:
            id: button
            text: "Button"
            on_press: root.crick()

Answer 1

我使用 ListProperty。

from kivy.properties import ListProperty

...

back_color = ListProperty([0.4, 0.4, 0.4, 1])

...


self.back_color = [175/255,238/255,238/255,1]