<p>使用<a href="https://kivy.org/docs/api-kivy.uix.floatlayout.html#kivy.uix.floatlayout.FloatLayout" rel="nofollow noreferrer">FloatLayout</a>作为根小部件,<a href="https://kivy.org/docs/api-kivy.uix.widget.html#kivy.uix.widget.Widget.pos_hint" rel="nofollow noreferrer">pos_hint: {'top': 1}</a>这样就可以将透明的BoxLayout放在顶部。至于透明度,使用按钮的<a href="https://kivy.org/docs/api-kivy.uix.button.html" rel="nofollow noreferrer">background_normal and background_color</a>。你知道吗</p>
<h2>片段</h2>
<pre><code>FloatLayout:
...
# topBox
BoxLayout:
Button:
text: 'Five (with transparent red background)'
background_normal: ''
background_color: 0.8, 0, 0, 0.5 # 5% red
size_hint: (0.5, 0.1)
pos_hint: {'top': 1}
</code></pre>
<h2>示例</h2>
<h2>你知道吗主.py你知道吗</h2>
<pre><code>from kivy.lang import Builder
from kivy.base import runTouchApp
runTouchApp(Builder.load_string('''
FloatLayout:
size: (300, 300)
# superBox
BoxLayout:
orientation: 'vertical'
# horizontalBox
BoxLayout:
# orientation: 'horizontal' - default orientation is horizontal
Button:
text: 'One'
Button:
text: 'Two'
# verticalBox
BoxLayout:
orientation: 'vertical'
Button:
text: 'Three'
Button:
text: 'Four'
# topBox
BoxLayout:
Button:
text: 'Five (with transparent red background)'
background_normal: ''
background_color: 0.8, 0, 0, 0.5 # 5% red
size_hint: (0.5, 0.1)
pos_hint: {'top': 1}
'''))
</code></pre>
<h2>输出</h2>
<p><a href="https://i.stack.imgur.com/4tzIf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/4tzIf.png" alt="Img01"/></a></p>