如何修复<Toolbox>中的“stderr: kivy.factory.FactoryException: Unknown class <Toolbox>”错误

Question

在阅读"kivy interactive am with python“这本书的同时，我试图构建一个UI，但我被这个静态代码卡住了，我逐字复制了这些代码。

这是主文件：

文件名: comiccreator.py

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.relativelayout import RelativeLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.gridlayout import GridLayout

Builder.load_file('toolbox.kv')
Builder.load_file('drawingspace.kv')
Builder.load_file('generaloptions.kv')
Builder.load_file('statusbar.kv')

class ComicCreator(AnchorLayout):
    pass

class ComicCreatorApp(App):
    def build(self):
        return ComicCreator()

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

然后是.kv文件

文件名: toolbox.kv

ToolBox:

<ToolButton@ToggleButton>:
    size_hint: None, None
    size: 48, 48
    group: 'tool'

<ToolBox@GridLayout>:
    cols: 2
    padding: 2
    ToolButton:
        text: 'O'
    ToolButton:
        text: '?'
    ToolButton:
        text: '/'

文件名: drawingspace.kv

DrawingSpace:

<DrawingSpace@RelativeLayout>:
    Label:
        markup: True
        text: '[size=32px][color=#3e6643]The[/color] [sub]Comic[/sub][i][b][Creator[/b][/i][/size]'

文件名: generaloptions.kv

GeneralOptions:

<GeneralOptions@BoxLayout>:
    orientation: 'horizontal'
    padding: 2
    Button: 
        text: 'Clear'
    Button:
        text: 'Remove'
    ToggleButton:
        text: 'Group'
    Button:
        text: 'Color'
    ToggleButton:
        text: 'Gestures'

文件名: statusbar.kv

StatusBar:

<StatusBar@BoxLayout>:
    orientation: 'horizontal'
    Label:
        text: 'Total Figures: ?'
    Label:
        text: "Kivy Started"

错误消息：

stderr: kivy.factory.FactoryException: Unknown class <Toolbox>

Answer 1

只需删除

来自toolbox.kv顶部的ToolBox: