同时在Kivy动画

Question

我正在编写一个简单的光学幻觉应用程序来学习如何用Kivy编写代码。我想知道为什么我的程序崩溃，以及如何解决它。 如果我取消注释动画.start（self.c4）行然后我的程序运行得很好，所以我几乎可以肯定问题是两个动画同时运行。错误是什么？如何解决？在

我的.py文件：

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.properties import NumericProperty, ObjectProperty,\
ReferenceListProperty
from kivy.graphics import Color
from kivy.core.window import Window
from kivy.animation import Animation

class Circle(Widget):
    v = NumericProperty(0)

class Illusion(Widget):
    c1 = ObjectProperty(None)
    c2 = ObjectProperty(None)
    c3 = ObjectProperty(None)
    c4 = ObjectProperty(None)

    def __init__(self, **kwargs):
        super(Illusion, self).__init__(**kwargs)

        objects = (self.c1, self.c2, self.c3, self.c4)
        values = (0,1,0,0)

        for i, item in enumerate(objects):
            objects[i].v = values[i]

        self.start_illusion(instance = None, value = None)

    def start_illusion(self, instance, value):
        animation = Animation(v = 1, d = .25)
        animation.bind(on_complete=self.continue_illusion)
        animation.start(self.c3)
        animation.start(self.c4)

    def continue_illusion(self, instance, value):
        animation = Animation(v = 0, d = .25)
        animation.bind(on_complete=self.start_illusion)
        animation.start(self.c3)
        animation.start(self.c4)

class IllusionsApp(App):
    Window.clearcolor = (0,0,1,1)
    def build(self):
        return Illusion()

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

我的.kv文件：

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Answer 1

我认为问题可能是在每次调用on_complete函数时重新创建新的Animation。在

尝试使用repeat animation property.

def __init__(self, **kwargs):
        super(Illusion, self).__init__(**kwargs)

        objects = (self.c1, self.c2, self.c3, self.c4)
        values = (0,1,0,0)

        for i, item in enumerate(objects):
            objects[i].v = values[i]

        self.animation_v0 = Animation(v = 0, d = .25) + Animation(v = 1, d = .25)
        self.animation_v0.repeat = True
        self.animation_v1 = Animation(v = 1, d = .25) + Animation(v = 0, d = .25)
        self.animation_v1.repeat = True

        #self.animation_v0.bind(on_complete=self.start_illusion)
        #self.animation_v1.bind(on_complete=self.continue_illusion)

        self.animation_v0.start(self.c3)
        self.animation_v1.start(self.c4)

    def start_illusion(self, instance, value):
        self.animation_v0.start(self.c3)

    def continue_illusion(self, instance, value):
        self.animation_v1.start(self.c4)