Kivy：如何定义在打开 TabbedPanel 时激活哪个选项卡

Question

打开 TabbedPanel 时如何定义哪个选项卡处于活动状态？

这里我在左侧使用标签，因此希望标签 #3 在开始时处于活动状态，而不是标签 #1。

import kivy, os
from  kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.base import runTouchApp


Builder.load_string("""

<TabbedTestScreen>:

    TabbedPanel:
        do_default_tab: False
        tab_pos: 'left_top'
        tab_height: 90
        tab_width: 90

        TabbedPanelItem:
            text: '1'
            Label:
                text: '1'
        TabbedPanelItem:
            text: '2'
            Label:
                text: '2'
        TabbedPanelItem:
            text: '3' 
            id: home_tab
            Label:
                text: '3'                    

""")

class TabbedTestScreen(Screen):
    pass

runTouchApp(TabbedTestScreen())

Answer 1

您可以使用 switch_to 在 class 初始化时执行此操作：

from  kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import Screen
from kivy.base import runTouchApp
from kivy.properties import ObjectProperty
from kivy.clock import Clock



Builder.load_string("""

<TabbedTestScreen>:
    tab_panel: tab_panel
    home_tab: home_tab
    TabbedPanel:
        id: tab_panel
        do_default_tab: False
        tab_pos: 'left_top'
        tab_height: 90
        tab_width: 90

        TabbedPanelItem:
            text: '1'
            Label:
                text: '1'
        TabbedPanelItem:
            text: '2'
            Label:
                text: '2'
        TabbedPanelItem:
            text: '3' 
            id: home_tab
            Label:
                text: '3'                    
""")

class TabbedTestScreen(Screen):
    tab_panel = ObjectProperty(None)
    home_tab = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(TabbedTestScreen, self).__init__(**kwargs)
        Clock.schedule_once(lambda *args: self.tab_panel.switch_to(self.home_tab))



runTouchApp(TabbedTestScreen())

Kivy：如何定义在打开 TabbedPanel 时激活哪个选项卡

Kivy: how to define which Tab is to be active on opening a TabbedPanel

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