Python kivy: How can I fix "TypeError: object.__init__() takes no parameters"?

Question

我的代码有问题。我想在我的 python 文件中使用 kv 语言的数据实现一个字符串，以将设计添加到 "MDTextFieldClear"。我不确定错误是否必须在 kv 字符串中，但在使用 类 和 kv 字符串的缩进进行了一些测试后，我认为这可能是原因。 这是一些代码：

from kivymd.theming import ThemeManager
from kivymd.textfields import MDTextFieldClear    # KivyMD imports

class LayoutPy(FloatLayout):    # Widget class
    def __init__(self, **kwargs):
        super(LayoutPy, self).__init__(**kwargs)
        self.get_voc = MDTextFieldClear(helper_text="Please enter the translation", helper_text_mode="on_focus", max_text_length=12, multiline=False, color_mode="accent")
        self.add_widget(self.get_voc)

        # ... (few more widgets) ...#

Builder.load_string("""
#:import MDTextField kivymd.textfields.MDTextField
#:import MDTextFieldRound kivymd.textfields.MDTextFieldRound
#:import MDTextFieldClear kivymd.textfields.MDTextFieldClear
#:import MDTextFieldRect kivymd.textfields.MDTextFieldRect

<LayoutPy>:
    orientation: 'vertical'
    FloatLayout:
        MDTextFieldClear:
            hint_text: ""
            helper_text: "Enter translation"
            helper_text_mode: "on_focus"
            max_text_length: 10
""")

class KivyGUI(App):          # Main class for build
    theme_cls = ThemeManager()
    theme_cls.primary_palette = ("Blue")
    title = ('Lingu Trainer')
    main_widget = None

    def build(self):
        c = LayoutPy()
        d = Factory.TextFields()
        return c


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

错误如下：

Traceback (most recent call last): File "PATH_TO_MY_PYTHON_FILE", line 106, in KivyGUI().run()

File "C:\Users\username\Anaconda3\lib\site-packages\kivy\app.py", line 800, in run root = self.build()

File "PATH_TO_MY_PYTHON_FILE", line 100, in build c = LayoutPy()

File "PATH_TO_MY_PYTHON_FILE", line 54, in init self.get_voc = MDTextFieldClear(helper_text="Please enter the translation", helper_text_mode="on_focus", max_text_length=12, multiline=False, color_mode="accent")

File "C:\Users\username\Anaconda3\lib\site-packages\kivy\uix\boxlayout.py", line 131, in init super(BoxLayout, self).init(**kwargs)

File "C:\Users\username\Anaconda3\lib\site-packages\kivy\uix\layout.py", line 76, in init super(Layout, self).init(**kwargs)

File "C:\Users\username\Anaconda3\lib\site-packages\kivy\uix\widget.py", line 340, in init super(Widget, self).init(**kwargs)

File "kivy_event.pyx", line 243, in kivy._event.EventDispatcher.init TypeError: object.init() takes no parameters

Answer 1

问题 1 - 类型错误

 TypeError: object.__init__() takes exactly one argument (the instance to initialize)

根本原因

错误是由于属性 color_mode and/or multiline.

问题 2 - 继承不匹配

在您的 kv 文件中，为 class 规则 <LayoutPy>: 声明了属性 orientation。此属性适用于 BoxLayout。但是在您的 Python 脚本中，class LayoutPy() 继承了 FloatLayout.

解决方案

以下示例使用 BoxLayout 作为根。

main.py

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout

from kivymd.theming import ThemeManager
from kivymd.textfields import MDTextFieldClear


class LayoutPy(BoxLayout):

    def __init__(self, **kwargs):
        super(LayoutPy, self).__init__(**kwargs)

        self.get_voc = MDTextFieldClear(helper_text="Please enter the translation",
                                        helper_text_mode="on_focus", max_text_length=12,
                                        hint_text="Created in py"
                                        )
        self.add_widget(self.get_voc)


Builder.load_string("""
#:import MDTextFieldClear kivymd.textfields.MDTextFieldClear

<LayoutPy>:
    orientation: 'vertical'

    FloatLayout:
        MDTextFieldClear:
            hint_text: "kv: Created"
            helper_text: "Enter translation"
            helper_text_mode: "on_focus"
            max_text_length: 10

""")


class KivyGUI(App):
    theme_cls = ThemeManager()
    theme_cls.primary_palette = "Blue"
    title = 'Lingu Trainer'

    def build(self):
        return LayoutPy()


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

输出