在Kivy 1.10和Python 2.7.9中使用ScreenManager获取TextInput值

Question

Using Kivy 1.10.0 with Python 2.7.9 I am trying to get the TextInput value entered by user when Button (my_button2) is clicked .And although I have been able to get this working with GridLayout it seems like the method I am using is not working with ScreenManager with BoxLayout . Error received is : AttributeError: 'ScreenTwo' object has no attribute 'inpt' when my_button2

After clicking 'Next Screen ' button , it takes me to page where user enters text value , and 'print' button should print it

Please see below :

import kivy
from kivy.app import App
from kivy.uix.screenmanager import Screen, ScreenManager 
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput

class ScreenOne(Screen):

    def __init__ (self,**kwargs):

        super (ScreenOne, self).__init__(**kwargs)
        my_box1 = BoxLayout(orientation='vertical')
        my_button1 = Button(text="Next Screen ",size_hint_y=None,size_y=100)
        my_button1.bind(on_press=self.changer)     
        my_box1.add_widget(my_button1) 
        self.add_widget(my_box1)

    def changer(self,*args):
        self.manager.current = 'screen2'

class ScreenTwo(Screen):

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


        layout = BoxLayout(orientation='vertical')       
        self.add_widget(layout)
        inpt = TextInput(text="Some text ",size_y=50)       
        layout.add_widget(inpt)

        my_button2 = Button(text="Print ")      
        my_button2.bind(on_press=self.click)      
        layout.add_widget(my_button2)

        Home_btn = Button(text="Back")                      
        Home_btn.bind(on_press=self.home)
        layout.add_widget(Home_btn)

    def click(self,my_button2):

        entered_value = self.inpt.text
        print entered_value


    def home(self,*args):
        self.manager.current = 'screen1'


class TestApp(App):

        def build(self):
            my_screenmanager = ScreenManager()
            screen1 = ScreenOne(name='screen1')
            screen2 = ScreenTwo(name='screen2')
            my_screenmanager.add_widget(screen1)
            my_screenmanager.add_widget(screen2)       
            return my_screenmanager

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

second screen

Answer 1

When you use self you are trying to access members of the class, but in your case inpt it is not since it is a variable any, if you want to be a member of the class you must put forward self, in your case change:

inpt = TextInput(text="Some text ",size_y=50)       
layout.add_widget(inpt)

to:

self.inpt = TextInput(text="Some text ",size_y=50)       
layout.add_widget(self.inpt)

Note: I recommend you read OOP basics, if you are not going to have many of these problems.