問題描述

我正在嘗試在布局內居中放置一個圓圈.我目前正在做一些填充計算，但我也在尋找更好的方法.我想其中一個預定義的布局可能是更好的選擇.這是我的代碼正在生成的內容...

I am trying to center a circle inside a layout. I'm currently doing some padding calculations, but I'm also looking for a better way. I imagine one of the predefined layouts may be a better choice. Here's what my code is producing...

對于方形布局:

對于寬布局:

這是正確的行為，很好，但有更好的方法嗎?例如，我可以想象這對于非圓形形狀會變得混亂.

This is the right behavior, which is great, but is there a better way? I can imagine this getting messy with non-circle shapes, for example.

這是我的代碼:

#!/usr/bin/kivy
import kivy
kivy.require('1.7.2')

from random import random
from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.gridlayout import GridLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.relativelayout import RelativeLayout
from kivy.graphics import Color, Ellipse, Rectangle

class MinimalApp(App):
    title = 'My App'
    def build(self):
        root = RootLayout()
        return(root)

class RootLayout(AnchorLayout):
    pass

class Circley(RelativeLayout):
    pass

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

還有 KV:

#:kivy 1.7.2
#:import kivy kivy

<RootLayout>:
    anchor_x: 'center'                              # I think this /is/ centered
    anchor_y: 'center' 
    canvas.before:
        Color:
            rgba: 0.4, 0.4, 0.4, 1
        Rectangle:
            pos: self.pos
            size: self.size
    Circley:
        anchor_x: 'center'                          # this is /not/ centered.
        anchor_y: 'center' 
        canvas.before:
            Color:
                rgba: 0.94, 0.94, 0.94, 1
            Ellipse:
                size: min(self.size), min(self.size)
                pos: 0.5*self.size[0] - 0.5*min(self.size), 0.5*self.size[1] - 0.5*min(self.size)
                Label:
                    text: unicode(self.size)    # this is /not/ appearing
                    color: 1,0,0,1

推薦答案

Snippet using FloatLayout, size_hint and pos_hint:

Snippet using FloatLayout, size_hint and pos_hint:

from kivy.app import App
from kivy.lang import Builder

kv = '''
FloatLayout:
    Widget:
        size: min(root.size), min(root.size)
        size_hint: None, None
        pos_hint: {'center_x': .5, 'center_y': .5}
        canvas:
            Color:
                rgb: 1, 0, 0
            Ellipse:    
                size: self.size
                pos: self.pos
'''
Builder.load_string(kv)

class MyApp(App):
    def build(self):
        return Builder.load_string(kv)

MyApp().run()

日本國旗:

from kivy.app import App
from kivy.lang import Builder

kv = '''
FloatLayout:
    canvas:
        Color:
            rgb: 1, 1, 1
        Rectangle:    
            size: self.size
            pos: self.pos   
    Widget:
        size: min(root.size)/2, min(root.size)/2
        size_hint: None, None
        pos_hint: {'center_x': .5, 'center_y': .5}
        canvas:
            Color:
                rgb: 1, 0, 0
            Ellipse:    
                size: self.size
                pos: self.pos
'''
Builder.load_string(kv)

class MyApp(App):
    def build(self):
        return Builder.load_string(kv)

MyApp().run()

這篇關于在 Kivy 中將對象居中的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！