如何将登录页面连接到主屏幕？

问题描述 投票：0回答：1

我分别为起始页、注册页和登录页编写了代码。后来我写了导航栏的代码。它们可以单独运行，但是当我尝试将它们放在一起时，在我按下登录页面上的登录按钮后，最终显示了一个空白页面。

我期望的是登录页面的登录按钮会跳转到带有导航栏的主页。

这是我的代码：

main.py：

from kivy.core.text import LabelBase
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivymd.uix.floatlayout import MDFloatLayout
from kivymd.uix.behaviors import FakeRectangularElevationBehavior
from kivy.factory import Factory
from kivy.utils import get_color_from_hex
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.textinput import TextInput
import requests

Window.size = (310, 580)

class HomeScreen(Screen):
    def __init__(self, **kwargs):
        super(HomeScreen, self).__init__(**kwargs)
        self.add_widget(NavBarScreen())

    pass
class Myapp(MDApp):
    def build(self):
        screen_manager = ScreenManager()
        screen_manager.add_widget(Builder.load_file("start.kv"))
        screen_manager.add_widget(Builder.load_file("signup.kv"))
        screen_manager.add_widget(Builder.load_file("login.kv"))
        home_screen = HomeScreen(name="home")
        home_screen.add_widget(NavBarScreen())

        screen_manager.add_widget(home_screen)
        return screen_manager


    def change_color(self, instance):
        if instance in self.root.ids.values():
            current_id = list(self.root.ids.keys())[list(self.root.ids.values()).index(instance)]
            for i in range(4):
                if f"nav_icon{i}" == current_id:
                    self.root.ids[f"nav_icon{i + 1}"].text_color = 1, 0, 0, 1
                else:
                    self.root.ids[f"nav_icon{i + 1}"].text_color = 0, 0, 0, 1

    def goto_home_screen(self):
        self.root.current = "home"


if __name__ == "__main__":
    LabelBase.register(name="Poppins-Medium", fn_regular=r"C:\Users\User\Desktop\FONT\Poppins\Poppins-Medium.ttf")
    LabelBase.register(name="Poppins-SemiBold", fn_regular=r"C:\Users\User\Desktop\FONT\Poppins\Poppins-SemiBold.ttf")

    Factory.register("NavBarScreen", cls=NavBarScreen)
    Myapp().run()

main.kv

<HomeScreen>:
    BoxLayout:
        orientation: "vertical"

        MDToolbar:
            title: "Home"
            md_bg_color: app.theme_cls.primary_color
            left_action_items: [["menu", lambda x: app.root.toggle_nav_drawer()]]

home.kv：

<HomeScreen>:
    BoxLayout:
        orientation: "vertical"

        MDToolbar:
            title: "Home"
            md_bg_color: app.theme_cls.primary_color
            left_action_items: [["menu", lambda x: app.root.toggle_nav_drawer()]]

        MDBottomNavigation:
            panel_color: rgba(180, 187, 114, 255)
            text_color_active: rgba(246, 250, 247, 255)

            MDBottomNavigationItem:
                name: "screen 1"
                text: "Records"
                font_name: "Poppins-Medium"
                icon: "leaf"
                icon_color: rgba(231, 234, 168, 255)
                MDLabel:
                    text: "Here is chats!"
                    halign: "center"

            MDBottomNavigationItem:
                name: "screen 2"
                text: "Scan"
                font_name: "Poppins-Medium"
                icon: "image-plus"
                MDLabel:
                    text: "Here is coffee!"
                    font_name: "Poppins-Medium"
                    halign: "center"
            MDBottomNavigationItem:
                name: "screen 3"
                text: "Settings"
                font_name: "Poppins-Medium"
                icon: "cog"
                MDLabel:
                    text: "Here is Python!"
                    font_name: "Poppins-Medium"
                    halign: "center"
            MDBottomNavigationItem:
                name: "screen 4"
                text: "About"
                font_name: "Poppins-Medium"
                icon: "information"
                MDLabel:
                    text: "Here is Python!"
                    halign: "center"

**start.kv:**
MDScreen:
    name: "main"
    MDFloatLayout:
        md_bg_color:rgba(246, 250, 247, 255)
        Image:
            source: r"C:\Users\User\Desktop\FONT\PythoScan.png"
            pos_hint: {"center_x": .11, "center_y": .95}

        Image:
            source: r"C:\Users\User\Desktop\FONT\Pytho.png"
            size_hint:.8, .8
            pos_hint: {"center_x": .5, "center_y": .65}

        MDLabel:
            text: "Hello!"
            font_name: "Poppins-SemiBold"
            font_size: "23sp"
            pos_hint: {"center_y": .38}
            halign: "center"
            color: rgba (48, 62, 39, 255)

        MDLabel:
            text: "Best Place To Write Life Stories"
            font_name: "Poppins-SemiBold"
            font_size: "13sp"
            size_hint_x: .85
            pos_hint: {"center_x": .5, "center_y": .3}
            halign: "center"
            color: rgba(180, 187, 114, 255)

        Button:
            text: "LOGIN"
            size_hint: .66, .065
            pos_hint: {"center_x": .5, "center_y":.18}
            background_color: 0, 0, 0, 0
            font_name: "Poppins-SemiBold"
            on_release:
                root.manager.transition.direction = "left"
                root.manager.current = "login"
            canvas.before:
                Color:
                    rgb: rgba(48, 62, 39, 255)
                RoundedRectangle:
                    size: self.size
                    pos: self.pos
                    radius: [5]

        Button:
            text: "SIGNUP"
            size_hint: .66, .065
            pos_hint: {"center_x": .5, "center_y":.09}
            background_color: 0, 0, 0, 0
            font_name: "Poppins-SemiBold"
            color: rgba(48, 62, 39, 255)
            on_release:
                root.manager.transition.direction= "left"
                root.manager.current= "signup"
            canvas.before:
                Color:
                    rgb: rgba(48, 62, 39, 255)
                Line:
                    width: 1.2
                    rounded_rectangle: self.x, self.y, self.width, self.height, 5, 5, 5, 5, 100

登录.kv：

MDScreen:
    name: "login"
    MDFloatLayout:
        md_bg_color:rgba(246, 250, 247, 255)
        Image:
            source: r"C:\Users\User\Desktop\FONT\PythoFarmer.png"
            pos_hint: {"center_x": 0.8, "center_y": .1}
        MDIconButton:
            icon: "arrow-left"
            pos_hint: {"center_y": .95}
            user_font_size: "30sp"
            theme_text_color: "Custom"
            text_color: rgba(26, 24, 58, 255)
            on_release:
                root.manager.transition.direction = "right"
                root.manager.current = "home"

        MDLabel:
            text: "Welcome Back!"
            font_name: "Poppins-SemiBold"
            font_size: "26sp"
            pos_hint: {"center_x": .6,"center_y": .85}
            color: rgba(48, 62, 39, 255)

        MDLabel:
            text: "Sign in to continue"
            font_name: "Poppins-SemiBold"
            font_size: "18sp"
            pos_hint: {"center_x": .6, "center_y": .79}
            color: rgba(180, 187, 114, 255)

        MDFloatLayout:
            size_hint: .7, .07
            pos_hint: {"center_x":.5, "center_y":.63}
            TextInput:
                hint_text: "Username"
                font_name: "Poppins-Medium"
                size_hint_y: .75
                pos_hint: {"center_x":.52, "center_y":.5}
                background_color: 1, 1, 1, 0
                foreground_color: rgba(0, 0, 59, 255)
                cursor_color: rgba(0, 0, 59, 255)
                font_size: "14sp"
                cursor_width: "2sp"
                multiline: False

            MDFloatLayout:
                pos_hint: {"center_x": .5, "center_y": 0}
                size_hint_y: .03
                md_bg_color: rgba(178, 178, 178, 255)

        MDFloatLayout:
            size_hint: .7, .07
            pos_hint: {"center_x":.5, "center_y":.52}
            TextInput:
                hint_text: "Password"
                font_name: "Poppins-Medium"
                size_hint_y: .75
                pos_hint: {"center_x":.52, "center_y":.48}
                background_color: 1, 1, 1, 0
                foreground_color: rgba(0, 0, 59, 255)
                cursor_color: rgba(0, 0, 59, 255)
                font_size: "14sp"
                cursor_width: "2sp"
                multiline: False
                password: True

            MDFloatLayout:
                pos_hint: {"center_x": .5, "center_y": 0}
                size_hint_y: .03
                md_bg_color: rgba(178, 178, 178, 255)
        Button:
            text: "LOGIN"
            size_hint: .66, .065
            pos_hint: {"center_x": .5, "center_y":.34}
            background_color: 0, 0, 0, 0
            font_name: "Poppins-SemiBold"
            on_release:
                root.manager.transition.direction= "left"
                root.manager.current= "home"

            canvas.before:
                Color:
                    rgb: rgba(48, 62, 39)
                RoundedRectangle:
                    size: self.size
                    pos: self.pos
                    radius: [5]
        MDTextButton:
            text: "Forgot Password?"
            pos_hint: {"center_x":.5, "center_y":.46}
            color: rgba(48, 62, 39, 200)
            font_size: "12sp"
            font_name: "Poppins-Medium"

        MDLabel:
            text: "Don't have an account? "
            font_name: "Poppins-Medium"
            font_size: "11sp"
            pos_hint: {"center_x":.72, "center_y":.29}
            color: rgba(180, 187, 114, 255)

        MDTextButton:
            text: "Sign up"
            font_name: "Poppins-SemiBold"
            font_size: "11sp"
            color: rgba(180, 187, 114, 250)
            pos_hint: {"center_x":.72, "center_y":.29}
            on_release:
                root.manager.transition.direction = "left"
                root.manager.current = "signup"

注册.kv：

MDScreen:
    name: "signup"
    MDFloatLayout:
        md_bg_color:rgba(246, 250, 247, 255)
        Image:
            source: r"C:\Users\User\Desktop\FONT\Pytho2farmers.zip"
            pos_hint: {"center_x": 0.75, "center_y": .15}
        MDIconButton:
            icon: "arrow-left"
            pos_hint: {"center_y": .95}
            user_font_size: "30sp"
            theme_text_color: "Custom"
            text_color: rgba(26, 24, 58, 255)
            on_release:
                root.manager.transition.direction = "right"
                root.manager.current = "main"

        MDLabel:
            text: "Hi!"
            font_name: "Poppins-SemiBold"
            font_size: "26sp"
            pos_hint: {"center_x": .6,"center_y": .85}
            color: rgba(48, 62, 39, 255)

        MDLabel:
            text: "Create an account"
            font_name: "Poppins-SemiBold"
            font_size: "18sp"
            pos_hint: {"center_x": .6, "center_y": .79}
            color: rgba(180, 187, 114, 255)

        MDFloatLayout:
            size_hint: .7, .07
            pos_hint: {"center_x":.5, "center_y":.68}
            TextInput:
                hint_text: "Username"
                font_name: "Poppins-Medium"
                size_hint_y: .75
                pos_hint: {"center_x":.5, "center_y":.5}
                background_color: 1, 1, 1, 0
                foreground_color: rgba(0, 0, 59, 255)
                cursor_color: rgba(0, 0, 59, 255)
                font_size: "14sp"
                cursor_width: "2sp"
                multiline: False

            MDFloatLayout:
                pos_hint: {"center_x": .5, "center_y": 0}
                size_hint_y: .03
                md_bg_color: rgba(178, 178, 178, 255)

        MDFloatLayout:
            size_hint: .7, .07
            pos_hint: {"center_x":.5, "center_y":.57}
            TextInput:
                hint_text: "Farm ID"
                font_name: "Poppins-Medium"
                size_hint_y: .75
                pos_hint: {"center_x":.5, "center_y":.5}
                background_color: 1, 1, 1, 0
                foreground_color: rgba(0, 0, 59, 255)
                cursor_color: rgba(0, 0, 59, 255)
                font_size: "14sp"
                cursor_width: "2sp"
                multiline: False

            MDFloatLayout:
                pos_hint: {"center_x": .5, "center_y": 0}
                size_hint_y: .03
                md_bg_color: rgba(178, 178, 178, 255)

        MDFloatLayout:
            size_hint: .7, .07
            pos_hint: {"center_x":.5, "center_y":.46}
            TextInput:
                hint_text: "Password"
                font_name: "Poppins-Medium"
                size_hint_y: .75
                pos_hint: {"center_x":.5, "center_y":.5}
                background_color: 1, 1, 1, 0
                foreground_color: rgba(0, 0, 59, 255)
                cursor_color: rgba(0, 0, 59, 255)
                font_size: "14sp"
                cursor_width: "2sp"
                multiline: False
                password: True

            MDFloatLayout:
                pos_hint: {"center_x": .5, "center_y": 0}
                size_hint_y: .03
                md_bg_color: rgba(178, 178, 178, 255)


        Button:
            text: "CREATE"
            size_hint: .66, .065
            pos_hint: {"center_x": .5, "center_y":.34}
            background_color: 0, 0, 0, 0
            font_name: "Poppins-SemiBold"
            on_release:
                root.manager.transition.direction= "left"
                root.manager.current= "login"
            canvas.before:
                Color:
                    rgb: rgba(48, 62, 39)
                RoundedRectangle:
                    size: self.size
                    pos: self.pos
                    radius: [5]

我期望的是登录页面上的登录按钮将跳转到带有导航栏的主页，但在我按下登录页面上的登录按钮后，它最终显示一个空白页面。

python kivy navigationbar
1个回答
0
投票

以下是我认为看起来有问题的一些事情：

  1. 您已在 main.kv 和 home.kv 中定义了 HomeScreen kv 规则
  2. 不确定您正在使用 NavBarScreen 做什么。它没有在任何地方定义，但您已经注册了它。
  3. NavBarScreen 添加到 HomeScreen 的 __init__() 和 MDApp.build() 中，假设 NavBarScreen 是一个屏幕，则应将其添加到 ScreenManager。
  4. 我建议您为注册和登录屏幕创建 kv 规则，就像您为主屏幕所做的那样。
  5. home.kv 未加载，main.kv 未加载。
  6. 在 home.kv 中您定义了一个根小部件，在构建中您使用 ScreenManager 作为根小部件。
  7. 另一个建议，您可以在 kv 中定义 ScreenManager 和所有 Screen，并将 screennames 放在 Screen 实例下。我发现这使得代码维护更容易，因为所有屏幕名称都集中在一处。

这应该足以帮助你取得更多进步。祝你好运！

最新问题
© www.soinside.com 2019 - 2024. All rights reserved.