在kivy中有没有一种方法来显示所有的.txt文件？

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.filebrowser import FileBrowser

class FileBrowserApp(App):
    def build(self):
        layout = BoxLayout(orientation='vertical')
        button = Button(text='Open File Browser')
        button.bind(on_release=self.open_file_browser)
        layout.add_widget(button)
        return layout

    def open_file_browser(self, instance):
        browser = FileBrowser(select_string='Select', cancel_string='Cancel')
        browser.bind(on_success=self.file_selected)
        browser.bind(on_canceled=self.file_canceled)
        self.root.add_widget(browser)

    def file_selected(self, instance):
        if len(instance.selection) > 0:
            selected_file = instance.selection[0]
            if selected_file.endswith('.txt'):
                # Do something with the selected .txt file
                print(f'Selected file: {selected_file}')

    def file_canceled(self, instance):
        print('File selection canceled')

FileBrowserApp().run()