Kivy ToggleButton贝维

Question

我尝试在两个或多个标签之间建立一个切换，比如单选按钮。到目前为止，它可以通过ToggleButtonBehavior来改变组之间的状态，但是当我单击所选项目时，它将被取消选择，不应该这样做。在

class SelectButton(ToggleButtonBehavior, Label):
    active = BooleanProperty(False)
    def __init__(self, **kwargs):
        super(SelectButton, self).__init__(**kwargs)

        self.text='off'
        self.color=[1,0,1,1]

        self.bind(state=self.toggle)

    def toggle(self, instance, value):
        if self.state == 'down':
            self.text = 'on'
        else:
            self.text = 'off'

有没有办法让你的行为像单选按钮？在

Answer 1

有一个^{} property：

This specifies whether the widgets in a group allow no selection i.e. everything to be deselected.

allow_no_selection is a BooleanProperty and defaults to True

将其设置为False并使用组后，一切都开始按预期工作：

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.uix.behaviors import ToggleButtonBehavior
from kivy.properties import BooleanProperty
from kivy.lang import Builder

Builder.load_string('''
<MyWidget>:
    SelectButton:
        state: 'down'
        text: 'on'
    SelectButton
        state: 'normal'
        text: 'off'
    SelectButton
        state: 'normal'
        text: 'off'
''')

class SelectButton(ToggleButtonBehavior, Label):
    active = BooleanProperty(False)

    def __init__(self, **kwargs):
        super(SelectButton, self).__init__(**kwargs)

        self.allow_no_selection = False

        self.group = "mygroup"
        self.color=[1,0,1,1]

        self.bind(state=self.toggle)

    def toggle(self, instance, value):
        if self.state == 'down':
            self.text = 'on'
        else:
            self.text = 'off'

class MyWidget(BoxLayout):
    pass

class MyApp(App):
    def build(self):
        return MyWidget()

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