Question

我想在FloatLayout的中心绘制圆圈。根据我的知识，我只获得了默认值。为什么圆圈显示代码不是红色？你能解释一下获得必要坐标的过程吗？

import kivy
from kivy.config import Config
kivy.config.Config.set('graphics','resizable', False)


from kivy.app import App
from kivy.graphics import Color, Ellipse

from kivy.uix.widget import Widget
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.uix.button import Button



class Scene(FloatLayout):
    def __init__(self, **kwargs):
        super(Scene, self).__init__(**kwargs)

    def draw_circle(self):
        with self.canvas:
            Color=(1,0,0)
            circ = Ellipse(pos = (self.center_x, self.center_y), size=(20,20))

    def on_touch_down(self, touch):    
        pass

class Game(BoxLayout):
    def __init__ (self,**kwargs):
        super(Game, self).__init__(**kwargs)
        self.orientation = 'vertical'

        but1 = Button(text = 'button 1')
        self.add_widget(but1)

        self.scene =  Scene()
        self.add_widget(self.scene)


class TestApp(App):
    def build(self):
        game = Game()
        game.scene.draw_circle()

        return game

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

Answer 1

您应该在创建浮动布局时定义浮动布局的大小。

self.scene =  Scene(size=(300, 300))

然后您的圈子应位于FloatLayout尺寸的中心。

我还认为FloatLayout最好与size_hint和pos_hint一起使用，而不是固定坐标。

Answer 2

您可以使用draw_circle致电Clock，以确保首先完全启动布局然后确保像Color(1, 0, 0)一样创建颜色。不是Color = ()

from kivy.config import Config
Config.set('graphics','resizable', False)    
from kivy.app import App
from kivy.graphics import Color, Ellipse
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.clock import Clock


class Scene(FloatLayout):

    def draw_circle(self, dt):
        with self.canvas:
            Color(1,0,0)
            circ = Ellipse(pos = (self.center_x, self.center_y), size=(20,20))


class Game(BoxLayout):

    def __init__ (self,**kwargs):
        super(Game, self).__init__(**kwargs)
        self.orientation = 'vertical'

        but1 = Button(text = 'button 1')
        self.add_widget(but1)

        self.scene =  Scene()
        self.add_widget(self.scene)


class TestApp(App):
    def build(self):
        game = Game()
        Clock.schedule_once(game.scene.draw_circle) # call draw_circle on next frame

        return game

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

Kivy：chow获得FloatLayout中心的坐标

2 个答案: