ValueError: KivyMD: App对象必须从`kivymd.app.MDApp`继承

Question

由于某些原因，我不能让MDTextField工作。我觉得这很简单，但我就是想不通。有什么想法吗？

import kivymd
from kivy.app import App
from kivymd.app import MDApp
from kivy.uix.floatlayout import FloatLayout
from kivymd.theming import ThemeManager
from kivymd.uix.textfield import MDTextField


class MainApp(MDApp):

    theme_cls = ThemeManager()
    theme_cls.primary_palette = "Blue"
    theme_cls.theme_style = "Dark"

MainApp().run()

‘KV’

#:import MDTextField kivymd.uix.textfield.MDTextField

FloatLayout:
    size_hint: .8, .8
    pos_hint: {"center_x": .5, "center_y": .5}
    spacing: dp(100)
    orientation: 'vertical'

    MDTextField:

Answer 1

很明显，我的问题不在于文本字段，而在于主题管理器。因此，不是

import kivymd
from kivy.app import App
from kivymd.app import MDApp
from kivy.uix.floatlayout import FloatLayout
from kivymd.theming import ThemeManager
from kivymd.uix.textfield import MDTextField


class MainApp(MDApp):

    theme_cls = ThemeManager()
    theme_cls.primary_palette = "Blue"
    theme_cls.theme_style = "Dark"

MainApp().run()

我本该用

import kivymd
from kivy.app import App
from kivymd.app import MDApp
from kivy.uix.floatlayout import FloatLayout
from kivymd.uix.textfield import MDTextField


class MainApp(MDApp):
    def __init__(self, **kwargs):
        self.title = "BMI"
        self.theme_cls.theme_style = "Dark"
        self.theme_cls.primary_palette = "Blue"
        super().__init__(**kwargs)

MainApp().run()