Kivy更新微件

Question

我叫data.txt中包含的用戶名和密碼的文本文件閱讀。文本文件的格式爲：

USERNAME1
密碼1
USERNAME2
密碼2
USERNAME3
USERNAME3
等

我的用戶名讀取和做出相應按鈕，每個用戶名。當我第一次啓動程序時，它會顯示data.txt中的所有內容並且可以正常工作。但是，當我添加使用該程序的用戶時，它不會更新主屏幕上的用戶列表。我將如何更新列表？

import kivy 
from kivy.app import App 
from kivy.uix.screenmanager import Screen, ScreenManager, NoTransition 
from kivy.uix.boxlayout import BoxLayout 
from kivy.uix.floatlayout import FloatLayout 
from kivy.uix.label import Label 
from kivy.uix.button import Button 
from kivy.core.window import Window 
from kivy.config import Config 
from kivy.properties import ObjectProperty 
from kivy.uix.textinput import TextInput 
from kivy.uix.popup import Popup 
from numpy import loadtxt 
from kivy.uix.widget import Widget 
from os.path import sep, expanduser, isdir, dirname 
from kivy.uix.stacklayout import StackLayout 
from functools import partial 
from kivy.uix.scrollview import ScrollView 
from kivy.uix.gridlayout import GridLayout 

class AddUserWindow(Screen): 
    def __init__(self,**kwargs): 
     super (AddUserWindow,self).__init__(**kwargs) 
     addNewUserLayout = FloatLayout() 
     newUserLabel = Label(text="User Name:", font_size='15dp', size_hint = (.5, .05), pos = (500, 450), halign = 'right') 
     passwordLabel = Label(text="Password:", font_size='15dp', size_hint = (.5, .05), pos = (500, 400), halign = 'right') 
     confirmPasswordLabel = Label(text="Confirm Password:", font_size='15dp', size_hint = (.5, .05), pos = (500, 350), halign = 'right') 
     self.newUserInput = TextInput(text = "", size_hint = (.25, .05), pos = (875, 450), font_size='15dp', multiline = False, write_tab = False) 
     self.passwordInput = TextInput(text = "", password = True, size_hint = (.25, .05), pos = (875, 400), font_size='15dp', multiline = False, write_tab = False) 
     self.confirmPasswordInput = TextInput(text = "", password = True, size_hint = (.25, .05), pos = (875, 350), font_size='15dp', multiline = False, write_tab = False) 
     cancelButton = Button(text="Cancel",size_hint = (.2, .05), pos = (650,0)) 
     cancelButton.bind(on_press = self.changeToMainWindow) 
     okButton = Button(text="Ok",size_hint = (.2, .05), pos = (350,0)) 
     okButton.bind(on_press=self.newUserCheck) 
     addNewUserLayout.add_widget(cancelButton) 
     addNewUserLayout.add_widget(okButton) 
     addNewUserLayout.add_widget(newUserLabel) 
     addNewUserLayout.add_widget(passwordLabel) 
     addNewUserLayout.add_widget(confirmPasswordLabel) 
     addNewUserLayout.add_widget(self.newUserInput) 
     addNewUserLayout.add_widget(self.passwordInput) 
     addNewUserLayout.add_widget(self.confirmPasswordInput) 

     self.add_widget(addNewUserLayout) 

    def newUserCheck(self, *args): 

     if self.newUserInput.text == "": 
      content = Button(text = 'Close') 
      popup = Popup(title = 'Please enter user name', size_hint = (.4, .15), content = content, auto_dismiss = False) 
      content.bind(on_press = popup.dismiss) 
      popup.open() 
      return 

     if self.passwordInput.text == "": 
      content = Button(text = 'Close') 
      popup = Popup(title = 'Please enter password', size_hint = (.4, .15), content = content, auto_dismiss = False) 
      content.bind(on_press = popup.dismiss) 
      popup.open() 
      return 

     if self.confirmPasswordInput.text == "": 
      content = Button(text = 'Close') 
      popup = Popup(title = 'Please confirm password', size_hint = (.4, .15), content = content, auto_dismiss = False) 
      content.bind(on_press = popup.dismiss) 
      popup.open() 
      return 

     if self.passwordInput.text != self.confirmPasswordInput.text: 
      content = Button(text = 'Close') 
      popup = Popup(title = 'Passwords must match', size_hint = (.4, .15), content = content, auto_dismiss = False) 
      content.bind(on_press = popup.dismiss) 
      popup.open() 
      return 


     file = open('data.txt', 'r') 
     initial = file.readlines() 
     databaselines = sum(1 for line in open('data.txt')) 
     file.close() 


     users = databaselines/2 
     data = [[0 for x in range(2)] for y in range(users)] 
     currLine = 0 
     range(users) 
     for i in range(users): 
      data[i][0] = initial[currLine].rstrip() 
      data[i][1] = initial[currLine + 1].rstrip() 
      currLine += 2 

     inDatabase = 0 
     for i in range(users): 
      if data[i][0] == self.newUserInput.text: 
       inDatabase = 1 
       break 
     if inDatabase == 1: 
      content = Button(text = 'Close') 
      popup = Popup(title = 'Already in database', size_hint = (.4, .15), content = content, auto_dismiss = False) 
      content.bind(on_press = popup.dismiss) 
      popup.open() 
      return 

     with open("data.txt", "a") as dataFile: 
      dataFile.write(self.newUserInput.text + "\n") 
      dataFile.write(self.passwordInput.text + "\n") 
     self.changeToMainWindow 


    def changeToMainWindow(self, *args): 
     self.newUserInput.text = "" 
     self.passwordInput.text = "" 
     self.confirmPasswordInput.text = "" 
     self.manager.current = 'mainScreen' 

class MainWindow(Screen): 

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

     self.mainLayout = FloatLayout() 

     logoutButton = Button(text="Logout",size_hint = (.2, .1), pos = (650,0)) 
     logoutButton.bind(on_press = exit) 
     addNewUserButton = Button(text="New User",size_hint = (.2, .1), pos = (350,0)) 
     addNewUserButton.bind(on_press=self.changeToAddUser) 
     self.mainLayout.add_widget(logoutButton) 
     self.mainLayout.add_widget(addNewUserButton) 
     file = open('data.txt', 'r') 
     initial = file.readlines() 
     databaselines = sum(1 for line in open('data.txt')) 
     file.close() 


     users = databaselines/2 
     data = [[0 for x in range(2)] for y in range(users)] 
     currLine = 0 
     range(users) 
     for i in range(users): 
      data[i][0] = initial[currLine].rstrip() 
      data[i][1] = initial[currLine + 1].rstrip() 
      currLine += 2 

     self.layout = GridLayout(cols=1, spacing=10, size_hint_y=None) 
     self.layout.bind(minimum_height=self.layout.setter('height')) 
     for i in range(users): 
      self.btn = Button(text=data[i][0], size_hint_y=None, height=40) 
      self.layout.add_widget(self.btn) 
     self.root = ScrollView(size_hint=(.45, None), pos = (600, 100), size=(Window.width, Window.height)) 
     self.root.add_widget(self.layout) 

     self.mainLayout.add_widget(self.root) 
     self.add_widget(self.mainLayout) 




    def changeToAddUser(self, *args): 
     self.manager.current = 'addUserScreen' 



class TestApp(App): 
     def build(self): 
      self.my_screenmanager = ScreenManager(transition = NoTransition()) 
      self.mainScreen = MainWindow(name='mainScreen') 
      self.addUserScreen = AddUserWindow(name = 'addUserScreen') 
      self.my_screenmanager.add_widget(self.mainScreen) 
      self.my_screenmanager.add_widget(self.addUserScreen) 

      Window.size = (1200, 800) 
      return self.my_screenmanager 

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

非常感謝！

Answer 1

要麼你可以定義一個函數添加適當的小部件的佈局或者您也可以「乾淨」的佈局，再從數據庫中讀取每一個用戶。如果你有很多用戶，這可能需要一段時間。

要通過一個函數添加用戶：

class MainWindow(Screen): 

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

     [... create initial widgets ...] 

     [... read users from database ...] 

     for i in range(users): 
      self.add_user(data[i][0] 

     self.root = ScrollView(size_hint=(.45, None), pos = (600, 100), size=(Window.width, Window.height)) 
     self.root.add_widget(self.layout) 

     self.mainLayout.add_widget(self.root) 
     self.add_widget(self.mainLayout) 

    def add_user(self, text): 
     button = Button(text=text, size_hint_y=None, height=40) 
     self.layout.add_widget(button) 

然後添加一個新用戶時：

def newUserCheck(self, *args): 

    [... do checks ...] 
    [... write to file ...] 

    # replace `text` with whatever text you want to display 
    self.manager.get_screen("mainScreen").add_user(text) 

    # in your shown code you missed the() on this function call 
    self.changeToMainWindow() 

此外，我個人認爲你的代碼比較難讀。您可以創建一些功能並給他們打電話。 create_initial_widgets，read_users_from_database，write_user_to_database等