問題描述

我想制作一個(gè)可以旋轉(zhuǎn)加載微調(diào)器圖像的動(dòng)畫小部件.我查看了 Animation 類，它似乎可以完成這項(xiàng)工作.但是我找不到一種方法來不斷地在一個(gè)方向上旋轉(zhuǎn)小部件

I want to make an animated widget that would rotate the loading spinner image. I've looked into the Animation class and it seems like it can do the job. But I couldn't find a way to keep rotating the widget in a single direction constantly

這是我的代碼:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.image import Image
from kivy.graphics import Rotate
from kivy.animation import Animation
from kivy.properties import NumericProperty

Builder.load_string('''                                                                                                                                        
<Loading>:                                                                                                                                                 
    canvas.before:                                                                                                                                             
        PushMatrix                                                                                                                                             
        Rotate:                                                                                                                                                
            angle: self.angle                                                                                                                                  
            axis: (0, 0, 1)                                                                                                                                    
            origin: self.center                                                                                                                                
    canvas.after:                                                                                                                                              
        PopMatrix                                                                                                                                              
''')

class Loading(Image):
    angle = NumericProperty(0)
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        anim = Animation(angle = 360)
        anim += Animation(angle = -360)
        anim.repeat = True
        anim.start(self)


class TestApp(App):
    def build(self):
        return Loading()

TestApp().run()

當(dāng)您啟動(dòng)它時(shí)，您會(huì)看到該小部件在一個(gè)方向上旋轉(zhuǎn) 360 度，然后旋轉(zhuǎn)旋轉(zhuǎn).如何構(gòu)建動(dòng)畫序列，使角度不斷增加或每 360 次旋轉(zhuǎn)下降到 0?

When you launch it, you'll see that the widget rotates 360 degrees in one direction and then turns the rotation around. How could I build the animation sequence so that the angle would constantly keep increasing or would be dropped to 0 every 360-rotation?

推薦答案

您可以在 on_angle 方法中將角度設(shè)置為 0.這是一個(gè)稍作修改的版本:

You can set your angle to 0 inside on_angle method. Here's a slightly modified version:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
from kivy.animation import Animation
from kivy.properties import NumericProperty

Builder.load_string('''                               
<Loading>:
    canvas.before:
        PushMatrix
        Rotate:
            angle: root.angle
            axis: 0, 0, 1
            origin: root.center
    canvas.after:
        PopMatrix


    Image:
        size_hint: None, None
        size: 100, 100
        pos_hint: {'center_x': 0.5, 'center_y': 0.5}
''')

class Loading(FloatLayout):
    angle = NumericProperty(0)
    def __init__(self, **kwargs):
        super(Loading, self).__init__(**kwargs)
        anim = Animation(angle = 360, duration=2) 
        anim += Animation(angle = 360, duration=2)
        anim.repeat = True
        anim.start(self)

    def on_angle(self, item, angle):
        if angle == 360:
            item.angle = 0


class TestApp(App):
    def build(self):
        return Loading()

TestApp().run()

這篇關(guān)于如何在 Kivy 中制作重復(fù)的旋轉(zhuǎn)動(dòng)畫?的文章就介紹到這了，希望我們推薦的答案對(duì)大家有所幫助，也希望大家多多支持html5模板網(wǎng)！