python - 从另一个类中的 InputText 获取值。基维

Question

我正在尝试从 InputText 传递一个值，如下所示。但我总是得到一个空字符串。如果我写 InputText (text = 'test')，那么总是传输单词 test 而不是我输入的内容。如何在 UserAcount 类中获取我输入到 InputText()

中的值

from kivy.app import App 
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout 
from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.textinput import TextInput
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.metrics import dp

import sqlite3

conn = sqlite3.connect('diplom.sqlite', check_same_thread = False)


class EntryMenu(Screen):

    def __init__(self, **kw):
        super(EntryMenu, self).__init__(**kw)
        box = BoxLayout(padding=150,orientation='vertical')
        self.login = TextInput(text='', multiline=False)
        box.add_widget(self.login)
        self.password = TextInput(text='', multiline=False)
        box.add_widget(self.password)
        self.error = Label(text="")
        box.add_widget(self.error)
        box.add_widget(Button(text='Entry', on_press=self.buttonClicked))
        self.add_widget(box)

    def buttonClicked(self,btn):
        self.error.text=''
        with conn:
            cursor = conn.cursor()
            sql =f'''SELECT username,password
            FROM user
            WHERE username = '{self.login.text}';
            '''
            cursor.execute(sql)
            results = cursor.fetchall()
            if results:
                if self.password.text==results[0][1]:
                    set_screen('user_acount')
                elif self.password.text!=results[0][1]:
                    self.error.text = "error password"
            else:
                self.error.text = "can not search user"



class UserAcount(Screen):
    def __init__(self,login, **kw):
        super(UserAcount, self).__init__(**kw)
        box = BoxLayout(orientation='vertical')
        self.login=login
        name = Label(text=self.login)
        box.add_widget(name)
        back_button = Button(text='Exit', on_press=lambda x:
                             set_screen('menu'), size_hint_y=None, height=dp(40))   
        box.add_widget(back_button)
        self.add_widget(box)


def set_screen(name_screen):
    sm.current = name_screen


sm = ScreenManager()
sm.add_widget(EntryMenu(name='menu'))
sm.add_widget(UserAcount(EntryMenu().login.text,name='user_acount'))

class MyApp(App):
    def __init__(self, **kvargs):
        super(MyApp, self).__init__(**kvargs)

    def build(self):
        return sm


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

请告诉我我缺少什么。提前致谢

Answer 1

好的。我想通了，你只在开始时传递用户名，因此以后不会改变。此代码应该有效:

from kivy.app import App 
from kivy.uix.button import Button
from kivy.uix.widget import Widget
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout 
from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.textinput import TextInput
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.metrics import dp

import sqlite3

conn = sqlite3.connect('diplom.sqlite', check_same_thread = False)


class EntryMenu(Screen):

    def __init__(self,myapp, **kw):
        super(EntryMenu, self).__init__(**kw)
        box = BoxLayout(padding=150,orientation='vertical')
        self.myapp = myapp
        self.login = TextInput(text='', multiline=False)
        box.add_widget(self.login)
        self.password = TextInput(text='', multiline=False)
        box.add_widget(self.password)
        self.error = Label(text="")
        box.add_widget(self.error)
        box.add_widget(Button(text='Entry', on_press=self.buttonClicked))
        self.add_widget(box)

    def buttonClicked(self,btn):
        self.error.text=''
        with conn:
            cursor = conn.cursor()
            sql =f'''SELECT username,password
            FROM user
            WHERE username = '{self.login.text}';
            '''
            cursor.execute(sql)
            results = cursor.fetchall()
            if results:
                if self.password.text==results[0][1]:
                    self.myapp.set_screen('user_acount', self.login.text)
                elif self.password.text!=results[0][1]:
                    self.error.text = "error password"
            else:
                self.error.text = "can not search user"



class UserAcount(Screen):
    def __init__(self,login,myapp, **kw):
        super(UserAcount, self).__init__(**kw)
        box = BoxLayout(orientation='vertical')
        self.myapp = myapp
        self.login=login
        name = Label(text=self.login)
        box.add_widget(name)
        back_button = Button(text='Exit', on_press=lambda x:
                             myapp.set_screen('menu'), size_hint_y=None, height=dp(40))   
        box.add_widget(back_button)
        self.add_widget(box)








class MyApp(App):
    def __init__(self, **kvargs):
        super(MyApp, self).__init__(**kvargs)
        self.sm = ScreenManager()
        self.username = ""
        self.userAcount = UserAcount(self.username,name='user_acount', myapp=self)
        self.sm.add_widget(self.userAcount)
        self.entryMenu = EntryMenu(name='menu', myapp=self)
        self.sm.add_widget(self.entryMenu)
        self.set_screen("menu")

    def build(self):
        return self.sm

    def set_screen(self, name_screen, username=None):
        if username != None and name_screen == "user_acount":
            self.username = username
            self.sm.remove_widget(self.userAcount)
            self.userAcount = UserAcount(self.username,name='user_acount', myapp=self)
            self.userAcount.login = self.username
            self.sm.add_widget(self.userAcount)
            
        self.sm.current = name_screen


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