如何从kivy文件获取Id值到python。我的代码是

Question

import kivy

from kivy.app import App

from kivy.lang import Builder

from kivy.config import Config

from kivy.core.window import Window

from kivy.properties import DictProperty
from datetime import date
import os

Window.size = (400,130)

from kivy.uix.boxlayout import BoxLayout

class MediBox(BoxLayout):

    from kivy.properties import ObjectProperty
    data = DictProperty({})

    theTxt = ObjectProperty(None)
    def getHere(self,*args):

        print('I want value here')

        print(len(args))

class MyApp(App):
    dateToday=str(date.today())
    def build(self):
        self.root = Builder.load_file('mediboxForm.kv')
        print("hiiiii")
        return self.root
if __name__ == '__main__':
    MyApp().run()

kv文件是

<MediBox@BoxLayout>:
    orientation: 'horizontal'
    mediBoxIn: 'default'
    theTxt: iAmTxt
    Label:
        text: root.mediBoxIn
    TextInput:
        id: iAmTxt


<MyApp@BoxLayout>:
    orientation: 'vertical'


    MediBox:
        id: firstName
        mediBoxIn: 'First Name'

    MediBox:
        id: middleName
        mediBoxIn: 'Middle Name'

    MediBox:
        id: lastName
        mediBoxIn: 'Last Name'


    MediBox:
        id: date
        mediBoxIn: 'Date'
        Label:
            text: app.dateToday

    MediBox:
        id: address
        mediBoxIn: 'Address Name'

    MediBox:
        id: phone
        mediBoxIn: 'Phone Number'

    MediBox:
        id: gender
        mediBoxIn: 'Gender'

    MediBox:
        id: age
        mediBoxIn: 'Age'

    Button:
        text: 'Submit  Patient Details'
        on_press: root.getHere()

MyApp