如何防止用户在登录 Kivy 之前越过应用程序的登录屏幕

Question

它转到的第一个屏幕是登录屏幕，但我可以绕过登录屏幕单击 Actionbar 上的任何按钮。我什至想删除 Actionbar 按钮，然后如果登录成功我可以将它们放回去但是，我无法弄清楚如何从登录屏幕 class 调用 Actionbar 的 id。防止用户绕过应用程序登录屏幕的最佳方法是什么？

Python代码：

from kivy.uix.behaviors import ButtonBehavior
from kivy.uix.image import Image
from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.clock import mainthread
from kivy.uix.button import Button
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.uix.scrollview import ScrollView


Builder.load_file('main.kv')


class Menu(BoxLayout):
    manager = ObjectProperty(None)


class ScreenLogIn(Screen):




    @mainthread
    def verify_credentials(self):


        try:



           if self.ids.login.text == "email@email.com" and self.ids.passw.text == "password":
            self.manager.current = "match"
        else:

            popup = Popup(title='Try again',
                          content=Label(text='Wrong Email/Password'),
                          size_hint=(None, None), size=(400, 400),
                          auto_dismiss=True)
            popup.open()
    except Exception as e:
        pass


class ScreenNearUsers(Screen):

    @mainthread
    def on_enter(self):

    for i in xrange(101):
        button = Button(text="B_" + str(i))
        self.ids.grid.add_widget(button)


class ScreenMatch(Screen):
    pass


class ScreenChats(Screen):
    pass


class ScreenUserProfile(Screen):
    pass


class Manager(ScreenManager):
    screen_log_in = ObjectProperty(None)
    screen_near_user = ObjectProperty(None)
    screen_match = ObjectProperty(None)
    screen_chats = ObjectProperty(None)
    screen_user_profile = ObjectProperty(None)


class MenuApp(App):

    def build(self):
       return Menu()


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

主kv：

<Menu>:
    manager: screen_manager
    orientation: "vertical"
    id: action
ActionBar:
    size_hint_y: 0.1
    background_color: 0, 0, 1000, 10
    background_normal: ""
    ActionView:
        ActionPrevious:
        ActionButton:
            id: near_users
            icon: 'icons/internet.png'
            on_press: root.manager.current = 'near_users'
        ActionButton:
            id: matching_bar
            text: "Matching"
            on_press: root.manager.current= 'match'
        ActionButton:
            id: chat
            text: "chat"
            on_press: root.manager.current = 'chats'
        ActionButton:
            id: profile
            text: "Profile"
            on_press: root.manager.current = 'profile'
Manager:
    id: screen_manager

<ScreenLogIn>:
     orientation: "vertical"
     id: login_screen
     BoxLayout:

     TextInput:
         id: login
     TextInput:
         id: passw
         password: True # hide password
     Button:
         text: "Log In"
         on_release: root.verify_credentials()

<ScreenNearUsers>:
    ScrollView:
        GridLayout:
            id: grid
            size_hint_y: None
            height: self.minimum_height
            cols: 2
            row_default_height: '20dp'
            row_force_default: True
            spacing: 0, 0
            padding: 0, 0

<ScreenMatch>:
    Button:
        text:

<ScreenChats>:
    Button:
        text: "stuff3"

<ScreenUserProfile>:
    Button:
        text: "stuff4"

<Manager>:
    id: screen_manager
    screen_log_in: screen_log_in
    screen_near_users: screen_near_users
    screen_match: screen_match
    screen_chats: screen_chats
    screen_user_profile: screen_user_profile

ScreenLogIn:
    id: screen_log_in
    name: 'login'
    manager: screen_manager
ScreenNearUsers:
    id: screen_near_users
    name: 'near_users'
    manager: screen_manager
ScreenMatch:
    id: screen_match
    name: 'match'
    manager: screen_manager
ScreenChats:
    id: screen_chats
    name: 'chats'
    manager: screen_manager
ScreenUserProfile:
    id: screen_user_profile
    name: 'profile'
    manger: screen_manager

Answer 1

解决方案

使用 BooleanProperty 和 ActionButton 的 disabled 属性（ActionButtons 变灰）来防止用户访问其他屏幕。

Python代码

将 BooleanProperty 添加到导入语句，from kivy.properties import ObjectProperty, BooleanProperty
添加布尔属性，access_denied = BooleanProperty(True)在class Menu()
在verify_credentials()方法中，如果密码匹配，设置access_denied为False，否则设置为True。

片段

from kivy.properties import ObjectProperty, BooleanProperty
...
class Menu(BoxLayout):
    access_denied = BooleanProperty(True)


class ScreenLogIn(Screen):

    def verify_credentials(self):
        try:
            if self.ids.login.text == "email@email.com" and self.ids.passw.text == "password":
                App.get_running_app().root.access_denied = False
                self.manager.current = "match"
            else:
                App.get_running_app().root.access_denied = True
                popup = Popup(title='Try again',
                              content=Label(text='Wrong Email/Password'),
                              size_hint=(None, None), size=(400, 400),
                              auto_dismiss=True)
                popup.open()
        except Exception as e:
            pass

kv 文件

检查 BooleanProperty，access_denied 在每个 ActionButton

片段

        ActionButton:
            id: near_users
            icon: 'icons/internet.png'
            disabled: True if root.access_denied else False
            on_press: root.manager.current = 'near_users'

        ActionButton:
            id: matching_bar
            text: "Matching"
            disabled: True if root.access_denied else False
            on_press: root.manager.current= 'match'

        ActionButton:
            id: chat
            text: "chat"
            disabled: True if root.access_denied else False
            on_press: root.manager.current = 'chats'

        ActionButton:
            id: profile
            text: "Profile"
            disabled: True if root.access_denied else False
            on_press: root.manager.current = 'profile'

Screen's default property manager

Each screen has by default a property manager that gives you the instance of the ScreenManager used.

例子

main.py

from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty, BooleanProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder
from kivy.uix.popup import Popup
from kivy.uix.label import Label
from kivy.uix.button import Button


Builder.load_file('main.kv')


class Menu(BoxLayout):
    access_denied = BooleanProperty(True)


class ScreenLogIn(Screen):

    def verify_credentials(self):
        try:
            if self.ids.login.text == "email@email.com" and self.ids.passw.text == "password":
                App.get_running_app().root.access_denied = False
                self.manager.current = "match"
            else:
                App.get_running_app().root.access_denied = True
                popup = Popup(title='Try again',
                              content=Label(text='Wrong Email/Password'),
                              size_hint=(None, None), size=(400, 400),
                              auto_dismiss=True)
                popup.open()
        except Exception as e:
            pass


class ScreenNearUsers(Screen):

    def on_enter(self):
        for i in range(101):
            button = Button(text="B_" + str(i))
            self.ids.grid.add_widget(button)


class ScreenMatch(Screen):
    pass


class ScreenChats(Screen):
    pass


class ScreenUserProfile(Screen):
    pass


class Manager(ScreenManager):
    screen_log_in = ObjectProperty(None)
    screen_near_user = ObjectProperty(None)
    screen_match = ObjectProperty(None)
    screen_chats = ObjectProperty(None)
    screen_user_profile = ObjectProperty(None)


class MenuApp(App):

    def build(self):
        return Menu()


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

main.kv

#:kivy 1.11.0

<Menu>:
    manager: screen_manager
    orientation: "vertical"
    id: action

    ActionBar:
        size_hint_y: 0.1
        background_color: 0, 0, 1000, 10
        background_normal: ""

        ActionView:
            ActionPrevious:

            ActionButton:
                id: near_users
                icon: 'icons/internet.png'
                disabled: True if root.access_denied else False
                on_press: root.manager.current = 'near_users'

            ActionButton:
                id: matching_bar
                text: "Matching"
                disabled: True if root.access_denied else False
                on_press: root.manager.current= 'match'

            ActionButton:
                id: chat
                text: "chat"
                disabled: True if root.access_denied else False
                on_press: root.manager.current = 'chats'

            ActionButton:
                id: profile
                text: "Profile"
                disabled: True if root.access_denied else False
                on_press: root.manager.current = 'profile'

    Manager:
        id: screen_manager

<ScreenLogIn>:
    orientation: "vertical"
    id: login_screen
    BoxLayout:
        TextInput:
            id: login
        TextInput:
            id: passw
            password: True # hide password
        Button:
            text: "Log In"
            on_release: root.verify_credentials()

<ScreenNearUsers>:
    ScrollView:
        GridLayout:
            id: grid
            size_hint_y: None
            height: self.minimum_height
            cols: 2
            row_default_height: '20dp'
            row_force_default: True
            spacing: 0, 0
            padding: 0, 0

<ScreenMatch>:
    Button:
        text:

<ScreenChats>:
    Button:
        text: "stuff3"

<ScreenUserProfile>:
    Button:
        text: "stuff4"

<Manager>:
    screen_log_in: screen_log_in
    screen_near_users: screen_near_users
    screen_match: screen_match
    screen_chats: screen_chats
    screen_user_profile: screen_user_profile

    ScreenLogIn:
        id: screen_log_in
        name: 'login'

    ScreenNearUsers:
        id: screen_near_users
        name: 'near_users'

    ScreenMatch:
        id: screen_match
        name: 'match'

    ScreenChats:
        id: screen_chats
        name: 'chats'

    ScreenUserProfile:
        id: screen_user_profile
        name: 'profile'

如何防止用户在登录 Kivy 之前越过应用程序的登录屏幕

How to keep users from getting past login screen of App before logging in Kivy

python

kivy

kivy-language

解决方案

Python代码

片段

kv 文件

片段

例子

main.py

main.kv

输出