如何在 kivy recycleview 中取消选择先前选择的行

Question

我需要帮助在 RecycleView 中使用 SelectableLabel 视图取消选择选定的标签项。 任何想法如何解决它？

我知道它应该写在“def apply_selection”的某个地方，但我无法让它工作

示例：

我希望能够再次单击选定的行，并且选择将被删除。

我认为这个代码应该放在这里：

    def apply_selection(self, rv, index, is_selected):
    ''' Respond to the selection of items in the view. '''
        self.selected = is_selected

我尝试使用第三个输入来指定当前选择，但它并没有真正起作用。 1.这个方法是我需要修改的地方以实现我想要的吗？ 2. 如果是这样，有什么正确的方法吗？

Answer 1

下面的代码就是按照要求做的，也就是

1. 一次只启用一个选择，并且
2. 启用取消选择所选项目

它与第一个答案的代码相同，除了突出显示的 3 个不同之处 ** 差异**。

从 kivy.app 导入应用程序
从 kivy.lang 导入生成器
从 kivy.uix.recycleview 导入 RecycleView
从 kivy.uix.recycleview.views 导入 RecycleDataViewBehavior
从 kivy.uix.label 导入标签
从 kivy.properties 导入 布尔属性
从 kivy.uix.recycleboxlayout 导入 回收箱布局
从 kivy.uix.behaviors 导入 FocusBehavior
从 kivy.uix.recycleview.layout 导入布局选择行为

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>:
    viewclass: 'SelectableLabel'
    SelectableRecycleBoxLayout:
        default_size: None, dp(56)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'
        multiselect: False # ** DIFFERENCE **
        touch_multiselect: False # ** DIFFERENCE **
''')


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

    # required to authorise unselecting a selected item
    touch_deselect_last = BooleanProperty(True) # ** DIFFERENCE **


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 = not self.selected


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


class RVMainApp(App):
    def build(self):
        return RV()


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

Answer 2

常见问题解答

您是否希望能够多选行，然后取消选择 个别行？ – ikolim 2018 年 9 月 30 日 21:04

不只是按一次选择，然后再按一次取消选择 ,而且在选择不同的行时也要保持选择的变化。 也许更容易说我正在寻找列表视图行为 recycleview – amihai 2018 年 9 月 30 日 21:07

解决方案

以下解决方案不适用于multi-select。

如果未选择行则设置为选中，或者在已选中时取消选择。

片段

def apply_selection(self, rv, index, is_selected):
    ''' Respond to the selection of items in the view. '''
    self.selected = not self.selected

示例

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>:
    viewclass: 'SelectableLabel'
    SelectableRecycleBoxLayout:
        default_size: None, dp(56)
        default_size_hint: 1, None
        size_hint_y: None
        height: self.minimum_height
        orientation: 'vertical'
''')


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 = not self.selected


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


class TestApp(App):
    def build(self):
        return RV()


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

输出