如何使用奇异时钟更改按钮的颜色？

Question

我希望程序将按钮中存储的时间与当前时间进行比较。当我运行程序时，如果出现“早期”按钮，则按钮应更改为黄色；如果“按时”按钮，则应更改为绿色；如果是“延迟”，则按钮应更改为红色：

     honey = float(self.streak_button.id)
 AttributeError: 'MainApp' object has no attribute 'streak_button'

这是我的代码：

class MainApp(App):

    def build(self): # build() returns an instance
        self.store = JsonStore("streak.json") # file that stores the streaks:
        Clock.schedule_interval(self.check_streak, 1/30.)

        return presentation


    def check_streak(self, dt):
        honey = float(self.streak_button.id)
        #print(f"\tdelta={honey}")

        # used to give 30 minute grace period
        delay = honey + 1800
        check = False

        if honey > time.time() and honey < delay:
            check = True

        if honey > time.time():
            self.streak_button.color = 0,1,0

        if check == True:
            self.streak_button.color = 0,0,1

        if honey < time.time():
            self.streak_button.color = 1,0,0

def display_btn(self):
        # display the names of the streaks in a list on PageTwo
        with open("streak.json", "r") as read_file:
            data = json.load(read_file)

        for value in data.values():
            if value['delta'] is not None:
                print(f"action={value['action']}, delta={value['delta']}")
                self.streak_button = StreakButton(id=str(value['delta']), text=value['action'],
                                            on_press=self.third_screen)
                self.root.screen_two.ids.streak_zone.add_widget(self.streak_button)

Answer 1

使用以下命令更改Button的颜色：

• background_normal = ''＃设置纯色
• background_color = [1, 0, 0, 1]＃背景颜色，格式为（r，g，b，a）

Kivy Button » background_color

background_color

     

背景色，格式为（r，g，b，a）。

     

这是纹理颜色的乘数。默认纹理   是灰色的，因此只需设置背景颜色即可使颜色更深   结果。要设置纯色，请将background_normal设置为”。

     

background_color是ListProperty，默认为[1，   1，1，1]。

示例

main.py

from kivy.app import App
from kivy.uix.screenmanager import Screen
from kivy.uix.button import Button
from kivy.storage.jsonstore import JsonStore
from kivy.lang import Builder
from kivy.clock import Clock

import time
import json


class ScreenTwo(Screen):
    pass


Builder.load_string("""
<ScreenTwo>:
    GridLayout:
        id: streak_zone
        cols: 2
""")


class StreakButton(Button):
    # rgba = ListProperty([])

    def on_touch_down(self, touch):
        if self.collide_point(*touch.pos):
            print(f"\nCustomButton.on_touch_down: text={self.text}")
            self.dispatch('on_press')
            return True
        return super(StreakButton, self).on_touch_down(touch)


class TestApp(App):
    def build(self):
        self.store = JsonStore("streak.json")
        Clock.schedule_interval(self.check_streak, 1/30.)

        return ScreenTwo()

    def check_streak(self, dt):
        print(f"\ncheck_streak:")

        # check all buttons
        for child in reversed(self.root.ids.streak_zone.children):
            honey = float(child.id)
            print(f"\tdelta={honey}")

            # used to give 30 minute grace period
            delay = honey + 1800
            check = False

            if honey > time.time() and honey < delay:
                check = True

            if honey > time.time():
                print("\t\tearly")
                child.background_normal = ''
                child.background_color = [1, 1, 0, 1]    # Yellow colour

            elif check == True:
                print("\t\ton time")
                child.background_normal = ''
                child.background_color = [0, 1, 0, 1]    # Green colour

            elif honey < time.time():
                print("\t\tlate")
                child.background_normal = ''
                child.background_color = [1, 0, 0, 1]    # Red colour

    def display_btn(self):
        print(f"\ndisplay_btn:")

        with open("streak.json", "r") as read_file:
            data = json.load(read_file)

            for value in data.values():
                if value['delta'] is not None:
                    print(f"action={value['action']}, delta={value['delta']}")
                    streak_button = StreakButton(id=str(value['delta']), text=value['action'], on_press=self.third_screen)
                    self.root.ids.streak_zone.add_widget(streak_button)


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