python - 在 MDTab 中显示来自 API 请求的数据
问题描述
我正在尝试使用 Python 学习编码，并正在制作一个应用程序来跟踪使用 KivyMD 的用户的会话时间。目前，我试图通过从我的数据库中的 api 调用获取 json 数据来显示总时间。我编写了一个函数来获取和处理 json 数据以计算总时间。The function must fire automatically to show the data (variable: total_minutes) in the MDLabel time_labelwhen the Mijn sessieTab loads. 这是我变得非常困惑的地方。
我on_pre_enter在 Kivy 中找到了该函数，该函数在屏幕加载时触发该函数，但它仅在Screen类中有效，而在类中无效Tabs。Tabs如果我在课堂上执行 python 逻辑，我不知道如何在课堂上使用 python 变量Screen。我用 Objectproperty 和 Stringproperty 尝试了很多东西，但没有一个成功。我认为我在这里错过了更大的东西。
当您自己看到应用程序时，我将发布代码以使事情更清楚。出于安全原因，我用一个产生相同结果（浮点数）的小函数替换了 api 请求函数。
提前谢谢了！
main.py 文件
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.screenmanager import ScreenManager, Screen
from kivymd.uix.tab import MDTabsBase
from kivymd.font_definitions import fonts
from kivymd.icon_definitions import md_icons
from kivy.uix.floatlayout import FloatLayout
from kivy.properties import ObjectProperty, StringProperty
from kivy.uix.widget import Widget
from kivymd.uix.label import MDLabel
import requests
import json
from datetime import datetime
Window.size = (300, 500) # voor develop doeleinden mobielscherm
class Screen1(Screen):
pass
def on_pre_enter(self, *args):
def func(a, b):
total_minutes = a - b
return total_minutes
print(func(3000,1500))
class Screen2(Screen):
pass
class Screen3(Screen):
pass
class Screen4(Screen):
pass
class Tab_mijn_sessie(FloatLayout, MDTabsBase):
pass
class Tab_alarm(FloatLayout, MDTabsBase):
pass
class Tab_actieve_drinkers(FloatLayout, MDTabsBase):
pass
class Tab_score(FloatLayout, MDTabsBase):
pass
class Tab_achievments(FloatLayout, MDTabsBase):
pass
class Tab_historie(FloatLayout, MDTabsBase):
pass
class DemoApp(MDApp):
def build(self):
self.theme_cls.primary_palette = 'Red'
self.theme_cls.theme_style = 'Dark'
screen = Builder.load_file('demo_file.kv')
return screen
DemoApp().run()
demo_file.kv 文件
Screen:
NavigationLayout:
ScreenManager:
id:screen_manager
Screen1:
name: 'home_screen'
BoxLayout:
name: 'home_layout'
orientation: 'vertical'
MDToolbar:
title: 'Huidige sessie'
left_action_items: [['menu', lambda x: nav_drawer.set_state("open")]]
specific_text_color: 1,1,1,1
MDTabs:
id:home_tabs
tab_bar_height: '35dp'
text_color_active: 1,1,0,1
text_color_normal: 0,0,0,1
color_indicator: 0.95, 0.95, 0.1, 1
tab_indicator_anim: True
anim_duration: 0.2
tab_indicator_height: '3dp'
Tab_mijn_sessie:
text: 'Mijn sessie'
Tab_alarm:
text: 'Alarm'
Tab_actieve_drinkers:
text: 'Actieve drinkers'
MDToolbar:
id: bottom_toolbar_scr1
name: 'bottom_toolbar'
specific_text_color: 1,1,1,1
title: ' Sessie inactief..'
Screen2:
name: 'statistieken_screen'
BoxLayout:
name: 'statistieken_layout'
orientation: 'vertical'
MDToolbar:
title: 'Statistieken'
left_action_items: [['menu', lambda x: nav_drawer.set_state("open")]]
specific_text_color: 1,1,1,1
MDTabs:
id:home_tabs
tab_bar_height: '35dp'
text_color_active: 1,1,0,1
text_color_normal: 0,0,0,1
color_indicator: 0.95, 0.95, 0.1, 1
tab_indicator_anim: True
anim_duration: 0.2
tab_indicator_height: '3dp'
Tab_score:
text: 'Scorebord'
Tab_achievments:
text: 'Achievements'
Tab_historie:
text: 'Historie'
MDToolbar:
id: bottom_toolbar_scr2
name: 'bottom_toolbar'
specific_text_color: 1,1,1,1
title: ' Sessie inactief..'
Screen3:
name: 'logout_screen'
BoxLayout:
name: 'logout_layout'
orientation: 'vertical'
MDToolbar:
title: 'Uitloggen'
left_action_items: [['menu', lambda x: nav_drawer.set_state("open")]]
specific_text_color: 1,1,1,1
Widget:
Screen4:
name: 'profile_screen'
BoxLayout:
name: 'profile_layout'
orientation: 'vertical'
MDToolbar:
title: 'Profiel'
left_action_items: [['menu', lambda x: nav_drawer.set_state("open")]]
specific_text_color: 1,1,1,1
Widget:
MDToolbar:
id: bottom_toolbar_scr4
name: 'bottom_toolbar'
specific_text_color: 1,1,1,1
title: ' Sessie inactief..'
MDNavigationDrawer:
id:nav_drawer
BoxLayout:
orientation: 'vertical'
spacing: '8dp'
padding: '8dp'
Image:
source: 'avatar.jpg'
MDLabel:
text: ' Name'
front_style: 'Subtitle1'
size_hint_y: None
height: self.texture_size[1]
MDLabel:
text: ' email@hotmail.com'
front_style: 'Caption'
size_hint_y: None
height: self.texture_size[1]
ScrollView:
MDList:
OneLineIconListItem:
theme_text_color: 'Custom'
text_color: 244/255, 67/255, 54/255, 1
text: 'Huidige sessie'
on_press:
screen_manager.current = 'home_screen'
nav_drawer.set_state("close")
IconLeftWidget:
theme_text_color: 'Custom'
text_color: 0.95, 0.95, 0.1, 1
icon: 'beer'
on_press:
screen_manager.current = 'home_screen'
nav_drawer.set_state("close")
OneLineIconListItem:
theme_text_color: 'Custom'
text_color: 244/255, 67/255, 54/255, 1
text: 'Statistieken'
on_press:
screen_manager.current = 'statistieken_screen'
nav_drawer.set_state("close")
IconLeftWidget:
icon: 'history'
theme_text_color: 'Custom'
text_color: 0.95, 0.95, 0.1, 1
on_press:
screen_manager.current = 'historie_screen'
nav_drawer.set_state("close")
OneLineIconListItem:
theme_text_color: 'Custom'
text_color: 244/255, 67/255, 54/255, 1
text: 'Profiel'
on_press:
screen_manager.current = 'profile_screen'
nav_drawer.set_state("close")
IconLeftWidget:
icon: 'face-profile'
theme_text_color: 'Custom'
text_color: 0.95, 0.95, 0.1, 1
on_press:
screen_manager.current = 'profile_screen'
nav_drawer.set_state("close")
OneLineIconListItem:
theme_text_color: 'Custom'
text_color: 244/255, 67/255, 54/255, 1
text: 'Uitloggen'
on_press:
screen_manager.current = 'logout_screen'
nav_drawer.set_state("close")
IconLeftWidget:
icon: 'logout'
theme_text_color: 'Custom'
text_color: 0.95, 0.95, 0.1, 1
on_press:
screen_manager.current = 'logout_screen'
nav_drawer.set_state("close")
<Tab_mijn_sessie>:
MDLabel:
text: 'Total time'
font_style: 'H6'
halign: 'center'
pos_hint: {"center_x": .5, "center_y": .4}
MDLabel:
id : time_label
text: '(this has to display the total amount of time)'
font_style: 'Body2'
halign: 'center'
pos_hint: {"center_x": .5, "center_y": .3}
MDFlatButton:
theme_text_color: 'Custom'
text_color: 1,1,1,1
halign: 'center'
text:'Activate session'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .7}
on_press:
app.root.ids.bottom_toolbar_scr1.title = ' Sessie actief!'
app.root.ids.bottom_toolbar_scr1.specific_text_color = 0,1,0,1
app.root.ids.bottom_toolbar_scr2.title = ' Sessie actief!'
app.root.ids.bottom_toolbar_scr2.specific_text_color = 0,1,0,1
app.root.ids.bottom_toolbar_scr4.title = ' Sessie actief!'
app.root.ids.bottom_toolbar_scr4.specific_text_color = 0,1,0,1
<Tab_alarm>:
MDLabel:
halign: 'center'
text:'Alarm'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
<Tab_actieve_drinkers>:
MDLabel:
halign: 'center'
text:'Actieve drinkers'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
<Tab_score>:
MDLabel:
halign: 'center'
text:'Scorebord'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
<Tab_achievments>:
MDLabel:
halign: 'center'
text:'Achievments'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
<Tab_historie>:
FloatLayout:
MDLabel:
halign: 'center'
text:'Historie'
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
MDFlatButton:
id: flat
text: 'druk hier'
pos_hint: {"center_x": .5, "center_y": 0.4}
解决方案
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivymd.app import MDApp
from kivymd.uix.tab import MDTabsBase
from kivymd.icon_definitions import md_icons
KV = '''
BoxLayout:
orientation: "vertical"
MDToolbar:
title: "Example Tabs"
MDTabs:
id: tabs
on_tab_switch: app.on_tab_switch(*args)
<Tab>:
MDIconButton:
id: icon
icon: app.icons[0]
user_font_size: "48sp"
pos_hint: {"center_x": .5, "center_y": .5}
'''
class Tab(FloatLayout, MDTabsBase):
'''Class implementing content for a tab.'''
class Example(MDApp):
icons = list(md_icons.keys())[15:30]
def build(self):
return Builder.load_string(KV)
def on_start(self):
for name_tab in self.icons:
self.root.ids.tabs.add_widget(Tab(text=name_tab))
def on_tab_switch(
self, instance_tabs, instance_tab, instance_tab_label, tab_text
):
'''Called when switching tabs.
:type instance_tabs: <kivymd.uix.tab.MDTabs object>;
:param instance_tab: <__main__.Tab object>;
:param instance_tab_label: <kivymd.uix.tab.MDTabsLabel object>;
:param tab_text: text or name icon of tab;
'''
count_icon = [k for k, v in md_icons.items() if v == tab_text]
instance_tab.ids.icon.icon = count_icon[0]
Example().run()