我正在尝试让添加按钮在kivy中添加另外3个文本输入框

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button

class MyBoxLayout(BoxLayout):
    def __init__(self, **kwargs):
        super(MyBoxLayout, self).__init__(**kwargs)
        self.orientation = 'vertical'
        
        # 创建一个文本输入框
        self.text_input = TextInput()
        self.add_widget(self.text_input)
        
        # 创建一个按钮，并绑定添加文本输入框的方法
        self.add_button = Button(text='添加', on_press=self.add_text_input)
        self.add_widget(self.add_button)
        
    def add_text_input(self, instance):
        # 每次点击按钮时，创建一个新的文本输入框，并添加到布局中
        new_text_input = TextInput()
        self.add_widget(new_text_input)

class MyApp(App):
    def build(self):
        return MyBoxLayout()

if __name__ == '__main__':
    MyApp().run()