python - 在 Kivy 中通过 if 条件更改屏幕似乎不起作用

Question

我正在尝试创建一个按钮，当所有微调器都选择了值时，该按钮会移动到下一个屏幕。为了确定旋转器何时具有值(日、小时和分钟旋转器)，我为每个旋转器分配了 state 值。除了下面显示的 kv 代码中的 if 语句之外，大多数代码都按预期工作。

    Button:
    background_color: 0, 0, 0, 1
    size: (400, 130)
    size_hint: (None, None)
    pos_hint: {'right': 0.6, 'center_y': 0}
    on_press:
        root.hours_checking()
        if day.state == hours.state == minutes.state == AmPm.state == 'True': \
        root.manager.current = 'screen_three'

这部分代码由于某种原因似乎没有执行。不会转换到屏幕 3。

        if day.state == hours.state == minutes.state == AmPm.state == 'True': \
        root.manager.current = 'screen_three'

Spinner:
    id: day
    size_hint: None, None
    size: 100, 44
    pos_hint: {'center': (.5, .5)}
    text: 'Day'
    values: 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'
    on_text:
        root.on_day_select(self.text)
        state: 'True'
Spinner:
    id: hours
    size_hint: None, None
    size: 100, 44
    pos_hint: {'center': (.1, .5)}
    text: 'Hour'
    values: '01', '02', '03', '04', '05', '06', '07', '08', '09', '10', '11', '12'
    on_text:
        root.on_hours_select(self.text)
        state: 'True'
Spinner:
    id: minutes
    size_hint: None, None
    size: 100, 44
    pos_hint: {'center': (.3, .5)}
    text: 'Minutes'
    values: '00', '15', '30', '45'
    on_text:
        root.on_minutes_select(self.text)
        state: 'True'
Spinner:
    id: AmPm
    size_hint: None, None
    size: 100, 44
    pos_hint: {'center': (.4, .5)}
    text: 'AM/PM'
    values: 'a.m', 'p.m'
    on_text:
        root.on_AmPm_select(self.text)
        state: 'True'

这是我的整个代码。如果它有助于解决我的错误。

    import kivy

kivy.require('1.11.1')

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.label import Label
from kivy.uix.widget import Widget
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.config import Config
from kivy.animation import Animation
from kivy.clock import Clock
from datetime import datetime
from datetime import timedelta
from kivy.uix.dropdown import DropDown
from kivy.uix.button import Button
from kivy.base import runTouchApp
from kivy.uix.behaviors import ButtonBehavior
from kivy.uix.scrollview import ScrollView
from kivy.uix.gridlayout import GridLayout
from kivy.base import runTouchApp
from kivy.uix.spinner import Spinner

# You can create your kv code in the Python file
Builder.load_string("""
<ScreenOne>:
    FloatLayout:
        orientation: 'horizontal'
        canvas:
            Rectangle:
                source: 'back1.jpg'
                size: self.size
                pos: self.pos
    BoxLayout:
        Button:
            background_color: 0, 0, 0, 0
            on_press:
                # You can define the duration of the change
                # and the direction of the slide
                root.manager.transition.direction = 'up'
                root.manager.transition.duration = 1
                root.manager.current = 'screen_two'

    BoxLayout: 
        Label:
            id: blinky
            text: "Click Anywhere To Continue"
            font_size: '20sp'
            font_name: "Raleway-Regular"
            size_hint: (1.0, 0)
            alpha: 1
            color: (1, 1, 1, self.alpha)


<ScreenTwo>:
    FloatLayout:
        orientation: 'horizontal'
        canvas:
            Rectangle:
                source: 'back2.jpg'
                size: self.size
                pos: self.pos 
        Label:
            id: white_box
            size: (500,500)
            alpha: 1
            bcolor: (1, 1, 1, self.alpha)
        Button:
            background_color: 0, 0, 0, 1
            size: (400, 130)
            size_hint: (None, None)
            pos_hint: {'right': 0.6, 'center_y': 0.30}
            on_press:
                root.time_now()
                root.manager.current = 'screen_three'
        Button:
            background_color: 0, 0, 0, 1
            size: (400, 130)
            size_hint: (None, None)
            pos_hint: {'right': 0.6, 'center_y': 0}
            on_press:
                root.hours_checking()
                if day.state == hours.state == minutes.state == AmPm.state == 'True': \
                root.manager.current = 'screen_three' 
        Spinner:
            id: day
            size_hint: None, None
            size: 100, 44
            pos_hint: {'center': (.5, .5)}
            text: 'Day'
            values: 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday'
            on_text:
                root.on_day_select(self.text)
                self.state: 'True'
        Spinner:
            id: hours
            size_hint: None, None
            size: 100, 44
            pos_hint: {'center': (.1, .5)}
            text: 'Hour'
            values: '01', '02', '03', '04', '05', '06', '07', '08', '09', '10', '11', '12'
            on_text:
                root.on_hours_select(self.text)
                self.state: 'True'
        Spinner:
            id: minutes
            size_hint: None, None
            size: 100, 44
            pos_hint: {'center': (.3, .5)}
            text: 'Minutes'
            values: '00', '15', '30', '45'
            on_text:
                root.on_minutes_select(self.text)
                self.state: 'True'
        Spinner:
            id: AmPm
            size_hint: None, None
            size: 100, 44
            pos_hint: {'center': (.4, .5)}
            text: 'AM/PM'
            values: 'a.m', 'p.m'
            on_text:
                root.on_AmPm_select(self.text)
                self.state: 'True'

<ScreenThree>:
    BoxLayout:
        Button:
            background_color: 1, 0, 0, 1
            on_press:
                # You can define the duration of the change
                # and the direction of the slide
                root.manager.current = 'screen_two'
""")

# Create a class for all screens in which you can include
# helpful methods specific to that screen
Config.set('graphics', 'resizable', '0')  # 0 being off 1 being on as in true/false
Config.set('graphics', 'width', '960')
Config.set('graphics', 'height', '720')


class ScreenOne(Screen):
    pass

class ScreenTwo(Screen):
    def __init__(self, a=1):
        super(ScreenTwo, self).__init__()
        self.state = state
    def time_now(self):
        global now, month_now, date_now, day_now, hour_now, minute_now, time_now
        now = datetime.now()
        print(now)

        month_now = int(now.strftime("%m"))  # month in int
        print("month:", month_now)

        date_now = int(now.strftime("%d"))  # date in int
        print("date:", date_now)

        day_now = now.strftime("%A")  # day in str
        print("day of the week:", day_now)

        hour_now = int(now.strftime("%H")) * 100
        minute_now = int(now.strftime("%M"))
        time_now = hour_now + minute_now  # day in str in 24 hour format
        print("time:", time_now)

    def check_open(day_now, opening_days, time_now, opening_time):
        global isopen
        opening_days = ["Monday", "Tuesday", "Wednesday", "Thursday", "Saturday"]
        opening_time = [800, 2200]
        isopen = False
        if day_now in opening_days and time_now >= opening_time[0] and time_now <= opening_time[1]:
            isopen = True
            print("Is the store open? ", isopen)
            return isopen
        else:
            print("Is the store open? ", isopen)
            return
    def on_day_select(self, text):
        global day
        day = str(text)
    def on_hours_select(self, text):
        global hours
        hours = int(text)
    def on_minutes_select(self, text):
        global minutes
        minutes = int(text)
    def on_AmPm_select(self,text):
        global AmPm
        AmPm = str(text)
    def hours_checking(self):
        global AmPm
        global hours
        global minutes
        global day
        try:
            if 1 <= hours <= 11 and AmPm == 'a.m':
                pass
            elif 1 <= hours <= 12 and AmPm == 'p.m':
                hours += 12
            elif hours == 12 and AmPm == 'a.m':
                hours = 0
        except:
            print('error')
        else:
            print(day, hours, minutes)

    pass


class ScreenThree(Screen):
    pass


# The ScreenManager controls moving between screens
screen_manager = ScreenManager()

# Add the screens to the manager and then supply a name
# that is used to switch screens
screen_manager.add_widget(ScreenOne(name="screen_one"))
screen_manager.add_widget(ScreenTwo(name="screen_two"))
screen_manager.add_widget(ScreenThree(name="screen_three"))


class KivyTut2App(App):
    def blink_animation(self, dt):
        anim = Animation(alpha=0, duration=1) + Animation(alpha=1, duration=1)
        anim.repeat = True
        anim.start(screen_manager.get_screen('screen_one').ids.blinky)

    def build(self):
        Clock.schedule_once(self.blink_animation)
        return screen_manager


sample_app = KivyTut2App()
sample_app.run()

Answer 1

on_text:
    root.on_day_select(self.text)
    state: 'True'

state: True这一部分没有做任何有用的事情。我假设您使用的是 Python 3，因此它被解析为 annotation .

您可能想使用self.state = True 。除非您定义了state，否则这仍然不起作用。类上的属性(您可能没有)，也因为您的 if day.state == hours.state == minutes.state == AmPm.state == 1正在检查值 1，而不是值 'True'这是一个字符串。