Kivy 自定义按钮文本

Question

从 python 端向自定义按钮添加文本的最佳方法是什么？到目前为止，这是我的代码：

class CircularButton(ButtonBehavior, Widget):

        # code inspired from:
        # https://github.com/kivy/kivy/issues/4263#issuecomment-217430358
        # https://stackoverflow.com/a/42886979/6924364
        # https://blog.kivy.org/2014/10/updating-canvas-instructions-declared-in-python/

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

        self.add_widget(Label(text='test')) # <-- put this in the middle of the button

        with self.canvas:
            Color(rgba=(.5,.5,.5,.5))
            self.shape = Ellipse(pos=self.pos,size=self.size)

        self.bind(pos=self.update_shape, size=self.update_shape)

    def update_shape(self, *args):
        self.shape.pos = self.pos
        self.shape.size = self.size

    def collide_point(self, x, y):
        return Vector(x, y).distance(self.center) <= self.width / 2

当链接到 .kv 文件中的小部件时，您会看到“文本”标签出现在 (0,0) 而不是按钮顶部。为这个自定义按钮设置文本的最佳方式是什么？

Answer 1

如果你打算在按钮中间放置一个Label，点击文字时on_press事件将不起作用，最好直接使用Label，并且必须在canvas.before上进行绘制。

class CircularButton(ButtonBehavior, Label):
    def __init__(self, **kwargs):
        super(CircularButton,self).__init__(**kwargs)
        self.text='test'
        with self.canvas.before:
            Color(rgba=(.5,.5,.5,.5))
            self.shape = Ellipse(pos=self.pos,size=self.size)
        self.bind(pos=self.update_shape, size=self.update_shape)

    def update_shape(self, *args):
        self.shape.pos = self.pos
        self.shape.size = self.size

    def collide_point(self, x, y):
        return Vector(x, y).distance(self.center) <= self.width / 2