如何将一个属性绑定到 Kivy 中的另一个属性? [英] How can I bind a property to another property in Kivy?

问题描述

我想将小部件的属性绑定到子小部件的属性.因此，当根小部件属性发生更改时，更改也会传播到子属性.

I want to bind a property of a widget to a property of a child widget. Thus when the root widget property is changed, the change is propagated to the child property as well.

我是这样尝试的:

self._Child._MyProperty = self._MyProperty

这可行……有时.但有时它不起作用.我不知道它什么时候起作用，为什么不起作用，在什么条件下不起作用.

This works... sometimes. But sometimes it does not work. I cannot find out when it works or why and under which conditions it does not work.

在所有情况下，我都绑定到根小部件中的方法:

In all cases I have a binding to a method in the root widget as well:

self.bind(_MyPropert = self._MyPropertyChange)

在所有情况下都会调用此方法，但有时更改不会传播到子属性.

This method is called in all cases, but sometimes the change is not propagated to the child property.

即使感觉很自然，这也不起作用:

This does not work even if it feels very natural:

self.bind(_MyProperty = self._Child._MyProperty)

但在 Kivy，我可以做到:

But in Kivy, I could do:

<RootWidget>
    <ChildWidget>
        _MyProperty: self.parent._MyProperty

问题是我想用 Python，而不是 Kivy.

The problem is I want to do it in Python, not in Kivy.

推荐答案

要将一个属性绑定到另一个属性，您应该使用 setter 事件:

To bind one property to another you should use the setter event:

self.bind(_MyProperty=self._Child.setter('_MyProperty'))

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