Question

我尝试在切换卡罗素时自动为放置在另一类中的图像设置动画。使用该按钮，它可以正常工作，但不会自动运行。我用“ id”尝试了不同的方法，但是我对此还比较陌生，所以也许有一个普遍的错误。屏幕管理器中通常有2个屏幕，第二个屏幕通向卡鲁塞尔。由于简单，我将第一个屏幕显示出来。我还计划在Screen1中播放电影，并希望在用户切换到Screen2时停止播放。我认为主要问题是如何控制不同类中的函数。

from kivy.app import App
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.carousel import Carousel
from kivy.uix.label import Label
from kivy.animation import Animation
from kivy.uix.image import Image

Builder.load_string('''

#:import FadeTransition kivy.uix.screenmanager.FadeTransition

<Screen1>:
    name: "screen1"
    Image:
        id: image1
        source: './img/somearrowup.png'
        pos: 205, 145
    Label:
        text: 'Screen down'
    BoxLayout:
        size_hint: .85,.15                  
        Button:
            text: 'Anim1'
            on_release: root.anim1()

<Screen2>:
    name: "screen2"
    Image:
        id: image2
        source: 'somearrowdown.png'
        pos: 205, 55
    Label:
        text: 'Screen Up'
    BoxLayout:
        size_hint: .85,.15
        Button:
            text: 'Anim2'
            on_release: root.anim2()

<Carou>:
    Screen:
        Carousel:
            id: carousel
            on_index: root.on_index(*args)
            direction: 'top'
            Screen1:
            Screen2:

''')

class Screen1(Screen):    
    def anim1(self):
        self.ids.image1.pos = 205, 155
        animation = Animation(pos=(205, 145),t='out_elastic')
        animation.start(self.ids.image1)

class Screen2(Screen):
    def anim2(self):
        self.ids.image2.pos = 205, 55
        animation = Animation(pos=(205, 45),t='out_elastic')
        animation.start(self.ids.image2)

class Carou(BoxLayout):    
    def on_index(self, instance, value):
        if instance.current_slide.name == 'screen2':
            print ("here an animation in Screen2")
            screen = Screen2()  #doesn't work
            screen.anim2()      #doesn't work
        else:
            print ("here an animation in Screen1")
            #...

class StartMenu(App):        
    def build(self):        
        sm = ScreenManager()        
        screen = Screen()        
        screen.add_widget(Carou())
        screen.name = 'carousel'
        sm.add_widget(screen)

        return sm

感谢您的帮助。

Answer 1

您的问题是，在您的on_index()方法中，您正在创建一个新的Screen2并调用其anim2()方法。您真正想要的是在anim2()中显示的Screen2实例中调用Carousel方法。为此，请替换：

screen = Screen2()

具有：

screen = instance.current_slide

在猕猴桃的不同屏幕上制作图像动画

1 个答案: