python-3.x - 如何在 kivy 的 2 个类之间传递变量？
问题描述
我最近开始在我的项目中使用 kivy。我正在尝试制作一个简单的数字咖啡菜单板。
我正在尝试显示用户选择的内容。在MenuScreen中，菜单被呈现给用户，然后用户可以选择。选择后，我想移动到另一个屏幕并显示“选择”，例如：Espresso
在咖啡杯图片的顶部。我到了可以手动编写要显示的字符串值的阶段。但是我无法显示用户选择的咖啡名称。
我确实被这个问题困扰了 2 天或大约 17 个小时的密集谷歌搜索和阅读文档，但是由于我的脑细胞有限，我无法解决它。我研究了绑定，在两个类之间传递变量等。任何帮助将不胜感激！！
短版python代码
class MenuScreen(Screen):
def __init__(self, **kwargs):
super(MenuScreen, self).__init__(**kwargs)
def buttonEspresso(self):
print ('Espresso Selected')
global selectedDrink
selectedDrink = self.coffeeName.text #<-------
sm.current = 'settings'
class SettingsScreen(Screen):
coffeeName = ObjectProperty(None)
def __init__(self, **kwargs):
super(SettingsScreen, self).__init__(**kwargs)
self.ids.coffeeName.text = selectedDrink #<-------
def backToMenu(self):
print('going back to menu')
sm.current = 'menu'
短版kivy代码 ：coffeeName：coffeeName GridLayout：cols：2
GridLayout:
cols:2
Button:
id: coffeeName
text: 'Espresso'
on_press:
root.manager.transition = FadeTransition()
root.text = 'Espresso'
root.buttonEspresso()
<SettingsScreen>:
coffeeName: coffeeName
GridLayout:
cols:2
GridLayout:
cols:1
Button:
text: 'Back to menu'
size_hint: None, None
size: 200, 50
on_press:
root.manager.transition = SlideTransition(direction="left")
root.backToMenu()
Label:
id: coffeeName #<-------
text: 'coffeeName'
font_size: 70
size_hint: None, None
size: 960, 50
AnchorLayout:
anchor_x: 'center'
anchor_y: 'center'
Image:
source: 'cappuccino.png'
size_hint: None, None
size: 1000, 1000
如果我选择“Espresso”，那么我想要的结果是“Espresso”显示在红色边框中。
上面的图像myDesiredOutcome是通过编辑制作的
self.ids.coffeeName.text = selectedDrink #<-------
用于说明目的
Python代码
import kivy
from kivy.app import App
from kivy.logger import Logger
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.video import Video
from kivy.uix.label import Label
from kivy.uix.button import Button
from kivy.lang import Builder
from kivy.uix.widget import Widget
from kivy.properties import StringProperty
from kivy.properties import ObjectProperty
import subprocess
import os
from omxplayer.player import OMXPlayer
class Player(Video):
def __init__(self, **kwargs):
super(Player, self).__init__(**kwargs)
self.player = OMXPlayer('video.mp4','--loop')
self.state='play'
self.options={'eos': 'loop'}
self.bind(on_touch_down = self.on_stop)
def check(self):
Logger.info("film position:" + str(self.position))
def on_stop(self, *args):
print ('I have been clicked')
#self.state='stop' # stop the video
self.player.quit()
sm.current = 'menu' # switch to the other Screen
class MenuScreen(Screen):
#coffeeName = ObjectProperty(None)
def __init__(self, **kwargs):
super(MenuScreen, self).__init__(**kwargs)
def buttonEspresso(self):
print ('Espresso Selected')
global selectedDrink
selectedDrink = self.coffeeName.text #<-------
sm.current = 'settings'
def buttonAmericano(self):
print ('Americano Selected')
sm.current = 'settings'
def buttonCafeLatte(self):
print ('Cafe Latte Selected')
sm.current = 'settings'
def buttonCappuccino(self):
print ('Cappuccino Selected')
sm.current = 'settings'
def buttonCafeMocha(self):
print ('Cafe Mocha Selected')
sm.current = 'settings'
def buttonMochaccino(self):
print ('Mochaccino Selected')
sm.current = 'settings'
class SettingsScreen(Screen):
coffeeName = ObjectProperty(None)
def __init__(self, **kwargs):
super(SettingsScreen, self).__init__(**kwargs)
self.ids.coffeeName.text = selectedDrink #<-------
def backToMenu(self):
print('going back to menu')
sm.current = 'menu'
Builder.load_file('screenManager.kv')
sm = ScreenManager()
screen1 = Screen(name='video')
screen1.add_widget(Player())
sm.add_widget(screen1)
sm.add_widget(MenuScreen(name='menu'))
sm.add_widget(SettingsScreen(name='settings'))
class VideoPlayerApp(App):
def build(self):
return sm
if __name__ == "__main__":
video = VideoPlayerApp()
try:
video.run()
except KeyboardInterrupt:
video.stop()
os.system('killall dbus-daemon')
基维代码
#:import FadeTransition kivy.uix.screenmanager.FadeTransition
#:import SlideTransition kivy.uix.screenmanager.SlideTransition
#:import GridLayout kivy.uix.gridlayout
<MenuScreen>:
coffeeName: coffeeName
GridLayout:
cols:2
GridLayout:
cols:2
Button:
id: coffeeName
text: 'Espresso'
on_press:
root.manager.transition = FadeTransition()
root.text = 'Espresso'
root.buttonEspresso()
Button:
text: 'Americano'
on_press:
root.manager.transition = FadeTransition()
root.buttonAmericano()
Button:
text: 'Cafe Latte'
on_press:
root.manager.transition = FadeTransition()
root.buttonCafeLatte()
Button:
text: 'Cappuccino'
on_press:
root.manager.transition = FadeTransition()
root.buttonCappuccino()
Button:
text: 'Cafe Mocha'
on_press:
root.manager.transition = FadeTransition()
root.buttonCafeMocha()
Button:
text: 'Mochaccino'
on_press:
root.manager.transition = FadeTransition()
root.buttonMochaccino()
GridLayout:
cols:2
Button:
text: 'Hot Chocolate'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
Button:
text: 'Creamy Chocolate'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
Button:
text: 'Express Coffee'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
Button:
text: 'Green Tea'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
Button:
text: 'Milk Tea'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
Button:
text: 'Roibos Tea'
on_press:
root.manager.transition = FadeTransition()
root.manager.current = 'settings'
#fading transition for video
<SettingsScreen>:
coffeeName: coffeeName
GridLayout:
cols:2
GridLayout:
cols:1
Button:
text: 'Back to menu'
size_hint: None, None
size: 200, 50
on_press:
root.manager.transition = SlideTransition(direction="left")
root.backToMenu()
Label:
id: coffeeName #<-------
text: 'coffeeName'
font_size: 70
size_hint: None, None
size: 960, 50
AnchorLayout:
anchor_x: 'center'
anchor_y: 'center'
Image:
source: 'cappuccino.png'
size_hint: None, None
size: 1000, 1000
GridLayout:
cols:1
Label:
font_size: 70
text: 'Select a Payment Option'
size_hint: None, None
size: 960, 200
BoxLayout:
size_hint: None, None
size: 960, 50
ToggleButton:
text: 'Cash'
font_size: 50
on_press:
print('on_press')
ToggleButton:
text: 'UniPay'
font_size: 50
ToggleButton:
text: 'Bank Cards'
font_size: 50
BoxLayout:
Button:
text: 'Back to menu'
on_press:
root.manager.transition = SlideTransition(direction="left")
root.manager.current = 'menu'
解决方案
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