python - 如何让按钮自动删除？

Question

因此，在 Kivy 中，您通常删除按钮的方式是访问它们的 id 或名称或其他内容。有什么方法可以访问按下的按钮的信息，以便按下按钮时可以自行删除吗？假设您有很多按钮并且您不知道 id，或者您有 100 个按钮并且需要很长时间？

Answer 1

删除小部件

使用remove_widget()从子列表中删除小部件。

    self.parent.remove_widget(self)

删除所有小部件/按钮

使用clear_widgets()从小部件中删除所有子项/按钮

        self.parent.clear_widgets()

许多按钮

实现一个继承 Button 的类，以及一个带有 collide_point() 函数的方法 on_touch_down 来检查触摸是否与我们的碰撞。小部件。

Kivy » Touch event basics

By default, touch events are dispatched to all currently displayed widgets. This means widgets receive the touch event whether it occurs within their physical area or not.

...

In order to provide the maximum flexibility, Kivy dispatches the events to all the widgets and lets them decide how to react to them. If you only want to respond to touch events inside the widget, you simply check:

def on_touch_down(self, touch):
    if self.collide_point(*touch.pos):
        # The touch has occurred inside the widgets area. Do stuff!
        pass

片段

class CustomButton(Button):

    def on_touch_down(self, touch):
        if self.collide_point(*touch.pos):
            print(f"\nCustomButton.on_touch_down: text={self.text}")
            self.parent.remove_widget(self)    # remove a widget / button
            # self.parent.clear_widgets()    # remove all children/ buttons
            return True    # consumed on_touch_down & stop propagation / bubbling
        return super(CustomButton, self).on_touch_down(touch)

示例

main.py

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.gridlayout import GridLayout
from kivy.lang import Builder


Builder.load_string("""
<Demo>:
    cols: 10
""")


class CustomButton(Button):

    def on_touch_down(self, touch):
        if self.collide_point(*touch.pos):
            print(f"\nCustomButton.on_touch_down: text={self.text}")
            self.parent.remove_widget(self)    # remove a widget / button
            # self.parent.clear_widgets()    # remove all children / buttons
            return True    # consumed on_touch_down & stop propagation / bubbling
        return super(CustomButton, self).on_touch_down(touch)


class Demo(GridLayout):

    def __init__(self, **kwargs):
        super(Demo, self).__init__(**kwargs)
        self.create_buttons()

    def create_buttons(self):
        for i in range(100):
            self.add_widget(CustomButton(id="Button" + str(i), text="Button"+str(i)))


class TestApp(App):

    def build(self):
        return Demo()


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

输出