如何在 KivyMD 的 .kv 文件中使用 kivy 中的数据表？

Question

我正在开发一个有两个屏幕的密码管理器应用程序。一个屏幕用于用户登录/注册，另一个屏幕用于向用户显示不同 url 的用户名和密码。我为此创建了一个单独的 kv 文件。现在在第二个屏幕中，我想添加一个数据表，它将以排列良好的格式显示用户数据。

根据 kivy 文档，我们只能在主程序中添加数据表，而不是在 .kv 文件中，但在我的情况下，我已经有一个 .kv 文件。那么如何在第二个屏幕的程序中添加数据表？

from kivy.config import Config
from kivy import Config
Config.set('graphics', 'width', '500')
Config.set('graphics', 'height', '600')
Config.set('graphics', 'resizable', 'False')
from kivy.lang import Builder
from kivymd.app import MDApp

from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.datatables import MDDataTable
import sqlite3


class MainWindow(Screen):
    pass


class SecondWindow(Screen):
    pass


class WindowManager(ScreenManager):
    pass

class MainApp(MDApp):
   
    def build(self):
      
       Config.set('graphics', 'resizable', False)
       self.theme_cls.theme_style = "Dark"
       self.theme_cls.primary_palette = "Purple"
     #  self.background_color = (0,0,0,0)
       
       return Builder.load_file("login.kv")
MainApp().run()

我的 .kv 文件------>

WindowManager:
    MainWindow:
    SecondWindow:

<MainWindow>:
    name: "main"

    MDCard:
        size_hint:None,None
        size:400,500
        pos_hint:{"center_x":.5,"center_y":.5}
        elevation:10
        padding:25
        spacing:25
        background_color:25

        orientation:"vertical"



<SecondWindow>:
    name: "second"
    BoxLayout:
        orientation:"vertical"
        size:root.width,root.height
        padding:30
        spacing:25

        Label:
            markup:True
            font_size:35
            text:"SAVED PASSWORDS"
            halign: "left"
            size_hint_y:  None
            height:self.texture_size[1]
            #padding_y:-15 
        
   

        MDDataTable:
            text: "Go Back"

Answer 1

你可以这样做（例如）

from kivymd.app import MDApp
from kivymd.uix.datatables import MDDataTable

from kivy.lang.builder import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.metrics import dp

KV = """
<LoginWindow>:
    name: "main"
    
    MDBoxLayout:
        orientation: 'vertical'
        padding: 10
        MDLabel:
            halign: "center"
            text: 'User login/registration'
        
        MDFloatingActionButton:
            icon: 'key'
            pos_hint: {'center_x': 0.5}
            on_release: 
                app.change_screen('second')
                app.add_datatable()

<DataWindow>:
    name: "second"
    MDBoxLayout:
        orientation: 'vertical'
        padding: 10
        MDFloatingActionButton:
            icon: 'arrow-left'
            on_release: app.change_screen('main')

        AnchorLayout:
            id: data_layout
    
WindowManager:
    LoginWindow:

    DataWindow:
        id: data_scr
"""


class LoginWindow(Screen):
    pass


class DataWindow(Screen):
    pass


class WindowManager(ScreenManager):
    pass


class Example(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.data_tables = None

    def build(self):
        return Builder.load_string(KV)

    def add_datatable(self):
        self.data_tables = MDDataTable(
            size_hint=(0.9, 0.8),
            column_data=[
                ("No.", dp(30)),
                ("User", dp(30)),
                ("Password", dp(30)),
            ],
            row_data=[
                (
                    "1",
                    "The pitonist",
                    "Strong password",
                ),
                (
                    "2",
                    "The c++ lover",
                    "Save me!!!:)",
                ),
            ]
        )
        self.root.ids.data_scr.ids.data_layout.add_widget(self.data_tables)

    def change_screen(self, screen: str):
        self.root.current = screen


Example().run()

Answer 2

你也可以通过这种方式做同样的事情

from kivymd.app import MDApp
from kivy.uix.screenmanager import Screen, ScreenManager
from kivymd.uix.datatables import MDDataTable
from kivy.metrics import dp
from kivy.uix.anchorlayout import AnchorLayout
from kivy.lang.builder import Builder

KV = """
ScreenManager:
    DemoPage:
    
    ClientsTable:


<DemoPage>:
    MDRaisedButton:
        text: " Next "
        size_hint: 0.5, 0.06
        pos_hint: {"center_x": 0.5, "center_y": 0.4}
        on_release: 
            root.manager.current = 'Clientstable'
            
            
<ClientsTable>:
    name: 'Clientstable'
 """


class ClientsTable(Screen):
    def load_table(self):
        layout = AnchorLayout()
        self.data_tables = MDDataTable(
            pos_hint={'center_y': 0.5, 'center_x': 0.5},
            size_hint=(0.9, 0.6),
            use_pagination=True,
            check=True,
            column_data=[
                ("No.", dp(30)),
                ("Head 1", dp(30)),
                ("Head 2", dp(30)),
                ("Head 3", dp(30)),
                ("Head 4", dp(30)), ],
            row_data=[
                (f"{i + 1}", "C", "C++", "JAVA", "Python")
                for i in range(50)], )
        self.add_widget(self.data_tables)
        return layout

    def on_enter(self):
        self.load_table()


class DemoPage(Screen):
    pass


sm = ScreenManager()

sm.add_widget(DemoPage(name='demopage'))
sm.add_widget(ClientsTable(name='Clientstable'))


class MainWindow(MDApp):
    def build(self):
        screen = Builder.load_string(KV)
        return screen


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