如何在Kivy开发的应用程序上编程复制到和粘贴到剪贴板按钮

from kivy.app import App
from kivy.uix.button import Button
from kivy.core.clipboard import Clipboard

class MyApp(App):
    def build(self):
        pass

class MyApp(App):
    def build(self):
        button = Button(text='复制到剪贴板', on_release=self.copy_to_clipboard)
        return button

    def copy_to_clipboard(self, instance):
        text_to_copy = '要复制的文本内容'
        Clipboard.copy(text_to_copy)

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