使用 Kivy 的时钟从 kivy 文件 (.kv) 访问不同 class 的 id/widget？

Question

我花了一天时间处理中的代码，我已将它与最简单的代码配对，因为我想做的是使用 Kivy 的时钟功能为我更改文本而不是点击按钮。

据我所知，更改文本的代码应该在程序的第 38 行，但我尝试的所有代码都停止执行，因为它无法访问文本来更改它。时钟功能在提供的代码中工作。

我已经让按钮按下处于活动状态，但我想更改文本的是时钟代码。我想知道是否有人知道解决方案。

提前致谢。

.....布拉德....

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.clock import Clock
from kivy.properties import ObjectProperty

Builder.load_string("""
<SingleScreen>:
    id: single_screen
    orientation: 'vertical'
    Button:
        text: "You Can Change Me By Button Press Here But I Really Want To Be Changed By Kivy's Clock Function"
        on_release: root.rooted()
    Change_Label:
        id: gb
<Change_Label>:
    _python_access: ChangeLabel
    Label:
        id: ChangeLabel
        text: "I'm Gonna Change."
""")

class SingleScreen(BoxLayout):

    def rooted(self):
        self.ids.gb._python_access.text = "I Changed It By Clicking!. But That's Not What I Wanted To Program!"

class Change_Label(BoxLayout):
    _python_access = ObjectProperty(None)

class OnlyScreen(App):
    def build(self):
        Clock.schedule_interval(self.Callback_Clock, 3)
        return SingleScreen()

    def Callback_Clock(self, dt):
        print "Hello, world! I'm the clock working...."
        # What code goes here that will change the text via Kivy's clock instead of using the button?

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

Answer 1

请执行以下操作，详情请参考我的示例：

片段

class OnlyScreenApp(App):

    def build(self):
        Clock.schedule_interval(self.Callback_Clock, 3)
        return SingleScreen()

    def Callback_Clock(self, dt):
        self.root.ids.gb._python_access.text = "I Changed It By Clock! dt=" + str(dt)

例子

main.py

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.clock import Clock
from kivy.properties import ObjectProperty


class SingleScreen(BoxLayout):
    pass


class Change_Label(BoxLayout):
    _python_access = ObjectProperty(None)


class TestApp(App):

    def build(self):
        Clock.schedule_interval(self.Callback_Clock, 3)
        return SingleScreen()

    def Callback_Clock(self, dt):
        self.root.ids.gb._python_access.text = "I Changed It By Clock! dt=" + str(dt)


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

test.kv

#:kivy 1.10.0

<SingleScreen>:
    id: single_screen
    orientation: 'vertical'
    Change_Label:
        id: gb

<Change_Label>:
    _python_access: ChangeLabel
    Label:
        id: ChangeLabel
        text: "I'm Gonna Change."

输出

Answer 2

根据上面 ikolim 的回答，我想 post 将解决方案作为一个完整的 python 程序，该程序与 post 问题的格式相关。非常感谢解决方案。完整的工作（一个文件）代码如下；

import kivy
kivy.require('1.9.1')
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.clock import Clock
from kivy.properties import ObjectProperty

Builder.load_string("""
<SingleScreen>:
    id: single_screen
    orientation: 'vertical'
    Change_Label:
        id: gb

<Change_Label>:
    _python_access: ChangeLabel
    Label:
        id: ChangeLabel
        text: "I'm Gonna Change."
""")

class SingleScreen(BoxLayout):
    pass


class Change_Label(BoxLayout):
    _python_access = ObjectProperty(None)


class OneScreen(App):

    def build(self):
        Clock.schedule_interval(self.Callback_Clock, 3)
        return SingleScreen()

    def Callback_Clock(self, dt):
        self.root.ids.gb._python_access.text = "I Changed It By Clock! dt=" + str(dt)


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

使用 Kivy 的时钟从 kivy 文件 (.kv) 访问不同 class 的 id/widget？

Accessing id/widget of different class from a kivy file (.kv) using Kivy's clock?

kivy

kivy-language

片段

例子

main.py

test.kv

输出