内部回收视图未显示在框布局中 - Kivy

Question

我在下面有这段代码 - 正在开发某种在线流媒体应用程序。

我的目标是让recycler view 项目占据 90%，而我的顶部导航占据 10%。 我所做的是将两者都放在box layout 中，但recycler view 项目似乎消失了。我没有收到错误，只是在应该显示 recycler view 项目的地方出现了一个空白屏幕。

我做错了什么 谢谢你的帮助

py

import os
from kivymd.app import MDApp
from kivy.uix.boxlayout import BoxLayout
from kivymd.uix.list import OneLineListItem, OneLineRightIconListItem, OneLineAvatarIconListItem, OneLineAvatarListItem, IRightBodyTouch
from kivymd.uix.gridlayout import MDGridLayout
from kivymd.uix.button import MDFlatButton, MDRectangleFlatButton, MDRaisedButton
from kivymd.uix.boxlayout import MDBoxLayout
from kivy.uix.recycleview import RecycleView
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.screen import MDScreen
from kivy.properties import StringProperty
from pathlib import Path, PurePath

# Music Path
storageLocation = Path.cwd()

if Path('Books').is_dir():
    storageLocation = Path.cwd() / 'Books'

    # Check if file is in SD card
# elif Path.is_mount():
else:
    storageLocation = Path.cwd() / 'Books'
    storageLocation.mkdir()

class RecycleViewRow(BoxLayout):
    text = StringProperty()


class MainScreen(MDScreen):
    def __init__(self, **kwargs):
        super(MainScreen, self).__init__(**kwargs)

        booksdir = [f for f in storageLocation.iterdir() if f.is_dir()]
        self.children[0].data = [{'text': str(x), 'id': str(x)} for x in booksdir]
        self.theFiles = [self.children[0].data]
        return

class Playlist(MDScreen):
    def on_enter(self, *args):
        return

class Main(MDApp):

    def build(self):
        self.theme_cls.theme_style = "Dark"
        sm = ScreenManager()
        sm.add_widget(MainScreen(name='MainScreen'))
        sm.add_widget(Playlist(name='Playlist'))
        sm.add_widget(Test(name="Test"))
        return sm

    def fill_playlist(self, dir):
        self.root.current = 'Playlist'  # this also clears the play list
        playlist = self.root.get_screen('Playlist')

        for sub in os.listdir(dir):
            playlist.ids.Box.add_widget(OneLineAvatarIconListItem(text=sub))
            

基维

<RecycleViewRow>:
    orientation: 'vertical'
    OneLineAvatarIconListItem:
        text: root.text
        #on_press: app.root.message_box(root.text)
        #on_release:app.root.current = 'Playlist'
        on_release: app.fill_playlist(root.text)
        Container:
            id: container

            MDIconButton:
                icon: "download"

<MainScreen>:
    MDBoxLayout
        orientation:'horizontal'
        MDToolbar:
            title: 'Books'
            left_action_items: [['menu', lambda x: x]]
            right_action_items: [['dots-vertical', lambda x: x]]

    MDBoxLayout
        RecycleView:
            id: rv
            viewclass: 'RecycleViewRow'
            spacing: 40
            padding:10, 10
            RecycleBoxLayout:
                default_size: None, dp(56)
                default_size_hint: 1, None
                size_hint_y: None
                height: self.minimum_height
                orientation: 'vertical'

<Playlist>
    MDBoxLayout:
        orientation:'vertical'
        spacing: 5
        size_hint_y: None
        height: self.minimum_height

        MDList:
            id:Box

Answer 1

您的代码的主要问题是：

self.children[0].data = [{'text': str(x), 'id': str(x)} for x in booksdir]

因为MainScreen 类中的self.children[0] 是MDBoxLayout。您应该为RecycleView 类设置数据，该类的id 为rv。所以那行应该是：

self.ids.rv.data = [{'text': str(x), 'id': str(x)} for x in booksdir]

但是，这在 MainScreen 的 __init__() 方法中不起作用，因为此时尚未分配 ids。以下是处理这两个问题的方法：

class MainScreen(MDScreen):
    def __init__(self, **kwargs):
        super(MainScreen, self).__init__(**kwargs)
        Clock.schedule_once(self.build_rv)

    def build_rv(self, dt):
        booksdir = [f for f in storageLocation.iterdir() if f.is_dir()]
        self.ids.rv.data = [{'text': str(x), 'id': str(x)} for x in booksdir]
        self.theFiles = [self.ids.rv.data]

通过使用Clock.schedule_once() 延迟build_rv() 的执行，ids 可用。