如何在 Kivy 中为倒数计时器创建圈功能

Question

我有一个倒数计时器，它从 randint() 参数给定范围内的随机整数开始，倒数到零。目的是使计时器在第一次达到零时以新的随机数重新启动（即圈功能）并在第二次达到零时显示 "FINISH"。

这是我第一次使用 kivy，如果解决方案很明显，我们深表歉意。目前我只需要两次迭代，但我可能需要稍后进行调整，以便计时器在最终停止之前可以循环任意次数。圈数将在运行应用程序之前在代码中确定，而不是由应用程序用户在运行应用程序时确定。

from kivy.app import App
from kivy.uix.label import Label
from kivy.animation import Animation
from kivy.properties import NumericProperty
from random import randint


class IncrediblyCrudeClock(Label):
    for i in range(2):
        r=randint(3,7)
        a = NumericProperty(r)  # Number of seconds to countdown


        def start(self):  #Function to initiate the countdown
            Animation.cancel_all(self)  # stop any current animations
            self.anim = Animation(a=0, duration=self.a)  #a=0 sets the 
#final destination of a. duration sets the time taken to reach stopping 
#point (i.e 5 seconds for a=5)
            def finish_callback(animation, incr_crude_clock):
                if self.i==1:
                    incr_crude_clock.text = "FINISHED"  #when the clock 
#reaches zero, display "FINISHED"
            self.anim.bind(on_complete=finish_callback)  #call the 
#finish_callback function once a=0
            self.anim.start(self)  #Start the animation (otherwise clock 
#stuck at 5 for a=5)


class TimeApp(App):
    def build(self):
        crudeclock = IncrediblyCrudeClock()
        crudeclock.start()
        return crudeclock

if __name__ == "__main__":
    TimeApp().run()



<IncrediblyCrudeClock>
    text: str(round(self.a, 1))

该应用按预期运行第一次倒计时。选择一个随机数，计时器倒计时到零，但在第一次倒计时后停止并显示 "FINISHED"。似乎 for 循环在应用程序实际启动之前从 0 迭代到 1，因此，在倒计时开始时，i 已经等于 1（而不是运行ning 首先从 a 到 0 i=0，然后从新的 a 到零，i=1）。我想这是因为 for 循环在错误的位置（即不是在调用 start 函数时），但我一直无法弄清楚如何纠正这个问题。这也是我第一次使用stack overflow，所以如果你需要知道任何其他的，请告诉我。

Answer 1

很难理解您的代码，但这里是您的 IncrediblyCrudeClock 版本：

class IncrediblyCrudeClock(Label):
    a = NumericProperty(0)  # Number of seconds to countdown

    def start(self):
        self.a = randint(3, 7)
        self.anim = Animation(a=0, duration=self.a)
        self.anim.bind(on_complete=self.secondAnim)
        print('starting first anim')
        self.anim.start(self)

    def secondAnim(self, animation, incr_crude_clock):
        self.a = randint(3, 7)
        self.anim = Animation(a=0, duration=self.a)
        self.anim.bind(on_complete=self.finish_callback)
        print('starting second anim')
        self.anim.start(self)

    def finish_callback(self, animation, incr_crude_clock):
        print('in finish_callback')
        self.text = 'FINISHED'

这是一个非常简单的方法。我确信 start 和 secondAnim 方法可以组合为一种方法，具有更多逻辑。

Answer 2

这是一个重复倒计时指定次数的版本：

from random import randint
from kivy.animation import Animation
from kivy.app import App
from kivy.lang import Builder
from kivy.properties import NumericProperty
from kivy.uix.label import Label


class IncrediblyCrudeClock(Label):
    a = NumericProperty(0)  # Number of seconds to countdown

    def __init__(self, **kwargs):
        self.max_laps = kwargs.pop('laps', 2)  # default is to do 2 laps
        self.lap_counter = 0
        super(IncrediblyCrudeClock, self).__init__(**kwargs)

    def start(self, *args):
        self.lap_counter += 1
        self.a = randint(3, 7)
        self.anim = Animation(a=0, duration=self.a)
        if self.lap_counter >= self.max_laps:
            # this is the last lap, set on_complete to call self.finish_callback
            self.anim.bind(on_complete=self.finish_callback)
        else:
            # not finished yet, call self.start again
            self.anim.bind(on_complete=self.start)
        print('starting anim number', self.lap_counter)
        self.anim.start(self)

    def finish_callback(self, animation, incr_crude_clock):
        print('in finish_callback')
        self.text = 'FINISHED'

Builder.load_string('''
<IncrediblyCrudeClock>
    text: str(round(self.a, 1))
''')


class TimeApp(App):
    def build(self):
        # specify the number of repetitions in the constructor
        crudeclock = IncrediblyCrudeClock(laps=3)
        crudeclock.start()
        return crudeclock

if __name__ == "__main__":
    TimeApp().run()

如何在 Kivy 中为倒数计时器创建圈功能

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