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我正在使用kivy2.0.0开发音乐播放器移动应用程序，在应用程序中有一个播放列表屏幕，其中包含 100多个名为“ MusicListItem ”的mdboxlayout小部件。

我的应用程序有这两个问题：

  1. 滚动部分滚动不流畅，有时在android设备上滚动时会选择一些东西
  2. 当我选择一个特定的项目时，我想要一个要调用的函数并将该选定项目的 MDIconButton 的图标更改为“暂停”。

这是我的 .py 文件

from kivy.lang import Builder
from kivymd.app import MDApp
from kivy.core.window import Window
from kivy.properties import StringProperty, ObjectProperty
from kivymd.theming import ThemableBehavior
from kivymd.uix.boxlayout import MDBoxLayout
from kivymd.uix.screen import MDScreen
from kivymd.uix.behaviors import RectangularRippleBehavior
from kivy.clock import Clock

Builder.load_file('playlist.kv')

KV = """
#:import FadeTransition kivy.uix.screenmanager.FadeTransition

ScreenManager:
    transition: FadeTransition()

    Playlist:
        name: "playlist screen"

"""

class Playlist(ThemableBehavior, MDScreen):
    rv = ObjectProperty()
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        Clock.schedule_once(self._finish_init)

    def music_list(self):
        return ['audio '+str(i) for i in range(1, 121)]

    def _finish_init(self, dt):
        self.set_list_musics()
        self.ids.rv.data[0]["icon"] = 'pause'

    def set_list_musics(self):
        """Builds a list of audios for the screen Playlist."""
        print(self.ids)

        def add_music_item(num, sura, secText, icon):
            self.ids.rv.data.append(
                {
                    "viewclass": "MusicListItem",
                    "number": num,
                    "text": sura,
                    "secondary_text": secText,
                    "icon": icon,
                    "callback": lambda x:x})
    
        for i in range(len(self.music_list())):
            music = self.music_list()
            add_music_item(str(i+1), music[i], '00:00:00', 'play')
         
    
class MusicListItem(ThemableBehavior, RectangularRippleBehavior, MDBoxLayout):
    text = StringProperty()
    secondary_text = StringProperty()
    number = StringProperty()
    icon = StringProperty()
    
    
class Mp3Player(MDApp):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
       
    def build(self):
        self.theme_cls.primary_palette = "Purple"
        self.theme_cls.theme_style = "Dark"
        return Builder.load_string(KV)


if '__main__' == __name__:
    Mp3Player().run()

.kv 文件

#: import gch kivy.utils.get_color_from_hex

<Playlist>
    md_bg_color: gch("#5D1049")
        
    MDGridLayout:
        cols: 1
        
        MDToolbar:
            left_action_items: [["menu", lambda x: x]]
            right_action_items: [["magnify", lambda x: x]]
            elevation: 10
            md_bg_color: 75/255, 6/255, 54/255, 1
            title: 'Playlist'
            pos_hint: {'top':1}
                    
        MDBoxLayout:
            orientation: 'vertical'
           
            RecycleView:
                id: rv
                viewclass: 'MusicListItem'

                RecycleBoxLayout:
                    padding: dp(10)
                    default_size: None, dp(60)
                    default_size_hint: 1, None
                    size_hint_y: None
                    height: self.minimum_height
                    orientation: 'vertical'

     
<MusicListItem>
    size_hint_y: None
    padding: dp(14)
    height: dp(60)

    canvas:
        Color:
            rgba:
                self.theme_cls.divider_color
        Line:
            points: (root.x+dp(10), root.y, root.x+self.width-dp(10)-0, root.y)

    MDBoxLayout:
        orientation: "horizontal"
        pos_hint: {"center_x": .5, "center_y": .5}

        MDBoxLayout:
            orientation: 'horizontal'
            MDBoxLayout:
                orientation: 'vertical'
                size_hint_x: .2
              
                MDLabel:
                    text: root.number
                    font_style: "H6"
                    adaptive_height: True
                
                MDLabel:
                    size_hint_y: .3
                 
            MDBoxLayout:
                orientation: 'vertical'
             
                MDLabel:
                    text: root.text
                    font_style: "Subtitle2"
                    adaptive_height: True
    
                MDLabel:
                    text: root.secondary_text
                    font_style: "Caption"
                    theme_text_color: "Hint"
                    adaptive_height: True

            MDIconButton:
                icon: root.icon

请任何帮助表示赞赏

4

1 回答 1

2

首先，我没有发现滚动问题。

其次，为了在其中选择特定项目，RecycleView您需要在该特定项目（视图类）中进行一些类似按钮的行为，这将在与之交互时触发一些操作。

因此，您的修改MusicListItem现在应该看起来像，

class MusicListItem(ThemableBehavior, RectangularRippleBehavior, ButtonBehavior, MDBoxLayout):
    text = StringProperty()
    secondary_text = StringProperty()
    number = StringProperty()
    icon = StringProperty()

    def on_release(self, *args):
        self.icon = "pause"
        print(f"Selected item no. {self.number}")

请记住在实例级别触发任何操作。

于 2022-01-15T07:04:00.090 回答