我是一个Kivy新手,尽管我读过几本书,相当多的Kivy文档,看过很多例子,但我仍然很难找到如何构建我的程序的方法。我正在尝试让一个文件选择器对话框工作。

我想从一个简单的BoxLayout界面开始,只需一个按钮。按此按钮时,我想显示文件选择器对话框。我从其中一本书中提取了很多代码。我的问题是如何调用LoadDialog小部件/类。我知道我的按钮不应该引用根。show_load_list(),但我不确定该如何引用它。如果你能给我一个正确的方向,我将不胜感激。

# File name: main.py
from kivy.app import App

from kivy.uix.floatlayout import FloatLayout
from kivy.properties import ObjectProperty
from kivy.lang import Builder


class LoadDialog(FloatLayout):
    load = ObjectProperty(None)
    cancel = ObjectProperty(None)

    def show_load_list(self):
        content = LoadDialog(load=self.load_list, cancel=self.dismiss_popup)
        self._popup = Popup(title="Load a file list", content=content, size_hint=(1, 1))
        self._popup.open()

    def load_list(self, path, filename):
        pass

    def dismiss_popup(self):
        self._popup.dismiss()

class LoadDialogApp(App):
    pass

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

我的kv文件定义为

# File name: loaddialog.kv

BoxLayout:
    Button:
        text: "Click me"
        on_release: root.show_load_list()

<LoadDialog>:
    BoxLayout:
        size: root.size
        pos: root.pos
        orientation: "vertical"
        FileChooserListView:
            id: filechooser
            path: './'
        BoxLayout:
            size_hint_y: None
            height: 30
            Button:
                text: "Cancel"
                on_release: root.cancel()
            Button:
                text: "Load"
                on_release: root.load(filechooser.path, filechooser.selection)