kivy/python：在树视图中选择节点时绑定事件

Question

test.py

from kivy.uix.screenmanager import Screen
from kivy.app import App
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.popup import Popup
from kivy.uix.treeview import TreeView, TreeViewLabel, TreeViewNode
from kivy.uix.label import Label
from kivy.properties import ObjectProperty



Window.size = (700, 530)


def populate_tree_view(tree_view, parent, node):
    if parent is None:
        tree_node = tree_view.add_node(TreeViewLabel(text=node['node_id'],
                                                     is_open=True))
    else:
        tree_node = tree_view.add_node(TreeViewLabel(text=node['node_id'],
                                                     is_open=True), parent)

    for child_node in node['children']:
        populate_tree_view(tree_view, tree_node, child_node)


tree = []
rows = [(1, 'test1', 11), (2, 'test2', 2), (3, 'test3', 3), (4, 'test4', 4), (5, 'test5', 1)]
for r in rows:
    tree.append({'node_id': r[1], 'children': []})



class TreeViewLabel(Label, TreeViewNode):
    pass


class TreeviewGroup(Popup):
    treeview = ObjectProperty(None)
    tv = ObjectProperty(None)
    #ti = ObjectProperty()

    def __init__(self, **kwargs):
        super(TreeviewGroup, self).__init__(**kwargs)
        self.tv = TreeView(root_options=dict(text=""),
                       hide_root=False,
                       indent_level=4)
        for branch in tree:
            populate_tree_view(self.tv, None, branch)
        self.remove_widgets()
        self.treeview.add_widget(self.tv)

    def remove_widgets(self):
        for child in [child for child in self.treeview.children]:
            self.treeview.remove_widget(child)

        
    def select_node(self, node):
        '''Select a node in the tree.
                '''
        if node.no_selection:
            return
        if self._selected_node:
            self._selected_node.is_selected = False
        node.is_selected = True
        self._selected_node = node
        print(node)

class GroupScreen(Screen):
    groupName = ObjectProperty(None)
    popup = ObjectProperty(None)

    def display_groups(self, instance):
        if len(instance.text) > 0:
            if self.popup is None:
                self.popup = TreeviewGroup()
            #self.popup.filter(instance.text)
            self.popup.open()


    def select_node(self, node):
        '''Select a node in the tree.
                '''
        if node.no_selection:
            return
        if self._selected_node:
            self._selected_node.is_selected = False
        node.is_selected = True
        self._selected_node = node
        print(node)


class Group(App):
   
    #rows = [(1, 'test1', 111), (2, 'test2', 112), (3, 'test3', 113), (4, 'test4', 114)]
    def build(self):
        self.root = Builder.load_file('test.kv')
        return self.root


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

test.kv

#:kivy 1.10.0

<TreeViewLabel>:
    on_touch_down:
        app.root.stateName.text = self.text
        app.root.popup.dismiss()

<TreeviewGroup>:
    id: treeview
    treeview: treeview
    title: "Select City"
    size_hint: None, None
    size: 400, 400
    auto_dismiss: False

    BoxLayout
        orientation: "vertical"
        #TextInput:
            #id: ti
            #size_hint_y: .1
            #on_text: root.filter(self.text)
        BoxLayout:
            id: treeview
            #on_press: root.select_node(self.text)
        Button:
            size_hint: 1, 0.1
            text: "Close"
            on_release: root.dismiss()


<CustomLabel@Label>:
    text_size: self.size
    valign: "middle"
    padding_x: 5

<SingleLineTextInput@TextInput>:
    multiline: False

<GreenButton@Button>:
    background_color: 1, 1, 1, 1
    size_hint_y: None
    height: self.parent.height * 0.150

GroupScreen:
    stateName: stateName

    GridLayout:
        cols: 2
        padding : 30,30
        spacing: 10, 10
        row_default_height: '40dp'

        CustomLabel:
            text: 'Name'

        SingleLineTextInput:
            id: stateName
            on_text: root.display_groups(self)

        CustomLabel:
            text: 'Code'

        CustomLabel:
            text: '08'


        GreenButton:
            text: 'Ok'
            #on_press: root.insert_data(stateName.text, cityName.text, shortName.text , pinCode.text)


        GreenButton:
            text: 'Cancel'
            on_press: app.stop()

        Label:

        Label:

当我在状态名称中输入任何内容时，会弹出一个带有树视图结构的弹出窗口。

我希望当单击任何节点时，它会从数据库中检索状态代码。并将值放在状态代码的前面。此时“08”是静态值。数据库查询对我来说没有问题，但我不知道如何将值放在状态代码前面后传入一个 .py 文件。并且弹出窗口应该关闭。

Answer 1

您可以通过向 Groupscreen 类添加一个字符串属性属性来表示状态码，然后编辑 select_node 方法以触发更改

...
from kivy.properties import ObjectProperty, StringProperty

...

class GroupScreen(Screen):
    groupName = ObjectProperty(None)
    popup = ObjectProperty(None)
    statecode = StringProperty('08')

...

    def select_node(self, node):
        '''Select a node in the tree.
            '''
        for r in rows:
            if node.text == r[1]:
                self.statecode = str(r[2])
                break

然后在kv中：

<TreeViewLabel>:
    on_touch_down:
        app.root.stateName.text = self.text
        app.root.select_node(self)
        app.root.popup.dismiss()

...

GroupScreen:
    stateName: stateName

    GridLayout:
        cols: 2
        padding : 30,30
        spacing: 10, 10
        row_default_height: '40dp'

        CustomLabel:
            text: 'State Name'

        SingleLineTextInput:
            id: stateName
            on_text: root.display_groups(self)

        CustomLabel:
            text: 'State Code'

        CustomLabel:
            text: root.statecode

...