Python > Kivy > 如何更改 RecycleView 中的數據 object

Question

我到處搜索，我找不到如何更新 Kivy 中的 RecycleView object 的數據。 我從文檔中獲取了示例，添加了一個按鈕，並希望將列表中的第一個變量從 1 更改為 101。

我已經讀過更新鏈接到recycleview的數據應該在數據更改后自動刷新視圖，但事實並非如此。 我嘗試在應用程序 class 中創建一個 ListProperty 變量並更改它，但不幸的是這也不起作用。

下面是我的代碼：

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, ListProperty
from kivy.uix.recycleboxlayout import RecycleBoxLayout
from kivy.uix.behaviors import FocusBehavior
from kivy.uix.recycleview.layout import LayoutSelectionBehavior

kv = ('''
<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
    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
Screen:
    BoxLayout:
        Button:
            text:'Change the RecycleView Data'
            on_release:
                print('Want to change the data here')
                root.ids.rv.change_line()
        RV:
''')


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(100)]

    def change_line(self):
        self.data[0] = '101'

class TestApp(App):
    data = ListProperty
    def build(self):
        self.root_widget = Builder.load_string(kv)
        return self.root_widget

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

Answer 1

您應該將 id 放在根 object 中。 這將使 id 被 root 識別。 而且您不需要調用“root.ids”。 在 kv 中調用 id 時。

kv = ('''
<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
Screen:
    BoxLayout:
        Button:
            text:'Change the RecycleView Data'
            on_release:
                print('Want to change the data here')
                rv.change_line() #<--- call the id inside kv
        RV:
            id: rv

''')

...
self.root_widget = Builder.load_string(kv)
self.root_widget.ids['rv'] #<---- calling the id within python script

完整代碼：

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, ListProperty
from kivy.uix.recycleboxlayout import RecycleBoxLayout
from kivy.uix.behaviors import FocusBehavior
from kivy.uix.recycleview.layout import LayoutSelectionBehavior

kv = ('''
<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
Screen:
    BoxLayout:
        Button:
            text:'Change the RecycleView Data'
            on_release:
                print('Want to change the data here')
                rv.change_line()
        RV:
            id: rv
''')

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(100)]

    def change_line(self):
        self.data[0] = '101'

class TestApp(App):
    data = ListProperty
    def build(self):
        self.root_widget = Builder.load_string(kv)
        return self.root_widget

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