用 RecycleView 替换 kivy Listview

Question

我目前正在尝试用 RecycleView 替换使用 ListView 的应用程序中的某些功能。

从文档中我无法弄清楚如何做到这一点。

当前的代码类似于这样：

ListView:
    id: x
    adapter:
        sla.SimpleListAdapter(data=[], cls=label.Label)


x.adapter.data.append(‘frank’)

是否有任何资源或提示来说明如何实现这一目标？ 我正在尝试使用 recycleview，因为 ListView 现在似乎已被弃用。

Answer 1

ListView 在 Kivy 版本 1.11.0 中被删除。下面的 sn-ps 显示了 RecycleView 中的等价物。 Kivy 文档中有两个RecycleView 的示例。

下面的 sn-ps 显示了使用 RecycleView 的等效项。

片段：kv 文件

RecycleView:
    id: x

    viewclass: 'Label'

    RecycleBoxLayout:
        default_size: None, dp(26)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'

片段：py 文件

x.data.append({'text‘: 'frank’)

示例

以下三个示例说明了 Kivy RecycleView。

• How to fetch data from database and show in table
• How to add vertical scroll in RecycleView

main.py

​​>

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

Builder.load_string('''
<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>:
    id: rv

    # Optional: ScrollView attributes
    bar_width: 5
    bar_color: 1, 0, 0, 1   # red
    bar_inactive_color: 0, 0, 1, 1   # blue
    effect_cls: "ScrollEffect"
    scroll_type: ['bars', 'content']

    viewclass: 'SelectableLabel'

    SelectableRecycleBoxLayout:
        default_size: None, dp(26)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'
        multiselect: True
        touch_multiselect: True
''')


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


class RV(RecycleView):
    def __init__(self, **kwargs):
        super(RV, self).__init__(**kwargs)
        self.data = [{'text': str(x)} for x in range(100)]
        self.data.insert(0, {'text': 'frank'})
        self.data.append({'text': 'liam'})


class TestApp(App):
    title = 'Kivy RecycleView Demo'

    def build(self):
        return RV()


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

输出