Kivy:I 想要 window 大小的按钮堆叠在屏幕顶部

Question

我想要 window 大小的不透明黑色按钮堆叠在屏幕顶部 当我按下不透明的黑色按钮时，按钮将消失，下面的屏幕将可见。 我尝试过，但一直失败。

下面是我的代码(.py)

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivy.animation import Animation
from kivy.clock import Clock

class First_Screen(Screen, BoxLayout):
    pass

class ScreenManagement(ScreenManager):
    pass

presentation = Builder.load_file("main.kv")

class TubucApp(App):
    def build(self):
        return presentation

TubucApp().run()

这是我的 .kv 文件：

ScreenManagement:
    transition:
    First_Screen:

<First_Screen>: #<-i want fullscreen-sized opaque black button covers
                #up this screen and will be disappear when i press the button
    name: 'First_Screen'
    BoxLayout:
        orientation: 'horizontal'
        spacing: 50 
        padding: [50, 50, 50, 50]
        canvas:
            Rectangle:
                pos: self.pos
                size: self.size 
                source: 'image/background.jpg'
        Button:
            id: campustown
            width: 40
            pos_hint: {'x' : 0, 'y':.45}
            size_hint: [.6,.1]
            background_normal:'image/test.png'
            background_down:'image/test2.png'
            border: (0,0,0,0)
            font_size: 15
            text: 'campus-town'

这两张图片展示了我想要完成的事情：

我该怎么做？

Answer 1

Python代码

1. 从 class First_Screen()
中删除 BoxLayout

片段 - Py

class First_Screen(Screen):
    pass

kv 文件

1. 为按钮添加一个 on_release 事件
2. 将background_normal设置为background_down

片段-kv

<First_Screen>:
    name: 'First_Screen'

    Button:
        id: campustown
        background_normal: 'image/test.png'
        background_down: 'image/test2.png'
        border: (0,0,0,0)
        font_size: 15
        text: 'campus-town'
        on_release:
            self.background_normal = self.background_down

输出