当我用生成器单击按钮时，如何从文本字段传递信息

Question

我刚开始使用kivymd，并试图创建一个简单的应用程序，只是为了好玩。我正试图创建一个注册屏幕，但当我试图将信息发送到控制台时，它会返回一个错误(kivy.properties.ObsObservableDict.getattrAttributeError:"super"对象没有属性">getattr"(，我实际上不明白这意味着什么。

.PY

''

from kivymd.app import MDApp
from kivy.lang.builder import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.button import MDRoundFlatButton
from screen_helper import screen_helper
from kivy.core.window import Window
Window.size = (300, 500)
class MenuScreen(Screen):
pass
class LoginScreen(Screen):
pass        
class RegistrarScreen(Screen):
pass
sm = ScreenManager()
sm.add_widget(MenuScreen(name='menu'))
sm.add_widget(LoginScreen(name='login'))
sm.add_widget(RegistrarScreen(name='registrar'))
class MainApp(MDApp):
def build(self):
self.theme_cls.primary_palette = 'Gray'
screen = Builder.load_string(screen_helper) 
return screen
def show_data(self):
print(self.root.ids.user.text)


MainApp().run()

''

.KV

''

screen_helper = """
ScreenManager:
RegistrarScreen:

<RegistrarScreen>:
name: "register"
MDTextField:
id: user
hint_text: 'Enter your user'
pos_hint: {'center_x':0.5,'center_y': 0.8}
size_hint_x: None 
width: 250  
MDRoundFlatButton:
id: register_btn
text: "Registrarse"
text_color: 0, 0, 0, 1
line_color: 0, 0, 0, 1
pos_hint: {'center_x':0.5,'center_y': 0.1}
width: 500
on_press: app.show_data()
"""

''

Answer 1

问题是您的show_data()方法正在尝试访问self.root.ids.user，但id不在self.root小部件(即ScreenManager(中。尝试将该方法更改为：

def show_data(self):
print(self.root.get_screen('register').ids.user.text)