Kivy：屏幕管理器内的可选 Recycleview

Question

我是 Kivy 的新手，我正在尝试在屏幕管理器中放置一个可选择的回收视图，但我无法弄清楚。 我也找不到关于它的例子。

谁能给我一个例子如何做到这一点？

Answer 1

如果您分享代码，对您的帮助会更简单。 但这是从 kivy 的内置示例构建的基本示例。

我希望它会有所帮助。

from kivy.app import App
from kivy.lang import Builder
from kivy.properties import BooleanProperty
from kivy.properties import NumericProperty
from kivy.uix.behaviors import FocusBehavior
from kivy.uix.label import Label
from kivy.uix.recycleboxlayout import RecycleBoxLayout
from kivy.uix.recycleview import RecycleView
from kivy.uix.recycleview.layout import LayoutSelectionBehavior
from kivy.uix.recycleview.views import RecycleDataViewBehavior
from kivy.uix.screenmanager import ScreenManager, Screen

Builder.load_string('''
#:import random random.random

<CustomScreen>:
    hue: random()
    canvas:
        Color:
            hsv: self.hue, .5, .3
        Rectangle:
            size: self.size

    Label:
        font_size: 42
        text: root.name

    Button:
        text: 'Next screen'
        size_hint: None, None
        pos_hint: {'right': 1}
        size: 150, 50
        on_release: root.manager.current = root.manager.next()

<SelectableLabel>:
    # Draw a background to indicate selection
    canvas.before:
        Color:
            rgba: (.0, 0.9, .1, .3) if self.selected else (0, 0, 0, 1)
        Rectangle:
            pos: self.pos
            size: self.size
<RV>:
    viewclass: 'SelectableLabel'
    SelectableRecycleBoxLayout:
        default_size: None, dp(56)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'
        multiselect: True
        touch_multiselect: True

<RVScreen>:
    BoxLayout:
        orientation: "vertical"
        RV:
        Button:
            text: 'Previous screen'
            size_hint: None, None
            size: 150, 50
            on_release: root.manager.current = root.manager.previous()

''')


class CustomScreen(Screen):
    hue = NumericProperty(0)


class SelectableRecycleBoxLayout(FocusBehavior, LayoutSelectionBehavior,
                                 RecycleBoxLayout):
    ''' Adds selection and focus behaviour to the view. '''


class SelectableLabel(RecycleDataViewBehavior, Label):
    ''' Add selection support to the Label '''
    index = None
    selected = BooleanProperty(False)
    selectable = BooleanProperty(True)

    def refresh_view_attrs(self, rv, index, data):
        ''' Catch and handle the view changes '''
        self.index = index
        return super(SelectableLabel, self).refresh_view_attrs(
            rv, index, data)

    def on_touch_down(self, touch):
        ''' Add selection on touch down '''
        if super(SelectableLabel, self).on_touch_down(touch):
            return True
        if self.collide_point(*touch.pos) and self.selectable:
            return self.parent.select_with_touch(self.index, touch)

    def apply_selection(self, rv, index, is_selected):
        ''' Respond to the selection of items in the view. '''
        self.selected = is_selected
        if is_selected:
            print("selection changed to {0}".format(rv.data[index]))
        else:
            print("selection removed for {0}".format(rv.data[index]))


class RV(RecycleView):
    def __init__(self, **kwargs):
        super(RV, self).__init__(**kwargs)
        self.data = [{'text': str(x)} for x in range(10)]


class RVScreen(Screen):
    pass


class ScreenManagerApp(App):

    def build(self):
        root = ScreenManager()
        root.add_widget(CustomScreen(name='CustomScreen'))
        root.add_widget(RVScreen(name='RVScreen'))
        return root


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