Question

我试图禁用Kivy按钮。为此，我创建了一个BooleanProperty，并将禁用的按钮属性设置为BooleanProperty。当我启动时，按钮被正确创建，其值已经分配（False）。但是，当我更新BooleanProperty时，按钮没有任何反应。当我点击时，我知道属性被正确绑定和更改，因为打印功能显示它已被更改。

可能是什么问题？我正在使用Kivy 1.10.0。我只保留了相关的代码行 - 我不认为我错过了什么，但我添加了关于什么有用的评论。

class LoginScreen(GridLayout):   
    def __init__(self, **kwargs):
        super(LoginScreen, self).__init__(**kwargs)
        self.selection = SelectionScreen()
        self.add_widget(self.selection)
        self.selection.bind(buttonStatus=self.disableButton)


    def disableButton(self, instance, value):
        self.selection.buttonStatus = value
        print(self.selection.buttonStatus) # returns True when I press button

class SelectionScreen(GridLayout):
    buttonStatus = BooleanProperty()

    # button to disable
    self.buttonStatus = False  # putting True disables button at launch
    btn = Button(text='BTN',disabled=self.buttonStatus)
    btn.bind(on_press=self.btnFunction)
    self.add_widget(btn)

    def btnFunction(self, value=None):
        self.buttonStatus = True # this updates property but interface not affected

Answer 1

btn = Button(text='BTN', disabled=self.buttonStatus)不会将buttonStatus属性与按钮的disabled属性绑定。为此，您可以将bind与setter方法一起使用：

self.bind(buttonStatus=btn.setter("disabled"))

基于您的代码的示例：

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.properties import BooleanProperty
from kivy.uix.button import Button


class MainWindow(GridLayout):
    buttonStatus = BooleanProperty()

    def __init__(self, *args, **kwargs):
        super(MainWindow, self).__init__(*args, **kwargs)
        self.cols = 1
        self.buttonStatus = False
        btn = Button(text='BTN', disabled=self.buttonStatus)
        btn.bind(on_press=self.btnFunction)
        self.bind(buttonStatus=btn.setter("disabled"))
        self.add_widget(btn)

    def btnFunction(self, *args):
        self.buttonStatus = True

class TestApp(App):
    def build(self):
        return MainWindow()

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

使用BooleanProperty（）禁用窗口小部件不起作用

1 个答案: