如何为 Kivy 中的按钮添加功能

How do I add functionality to a button in Kivy

我正在尝试为我在 Kivy 中的按钮添加功能,但它不起作用。

这是 python 文件的代码:

import kivy
kivy.require("1.9.1")
from kivy.uix.boxlayout import BoxLayout
from kivy.app           import App
from kivy.uix.label     import Label
from kivy.uix.button    import Button
class MainMenuApp(App):
    def build(self):
        return BoxLayout()
    def Play(self):
        print("Play Button Pressed")  
    def LeaderBoards(self):
        print("Leader Board Button Pressed")   
    def Credits(self):
        print("Credits Button Pressed")
    def Settings(self):
        print("Settings Button Pressed")
if __name__ == "__main__":
    MainMenuApp().run()

对于 kv 文件:

<BoxLayout>:
    orientation: "vertical"
    spacing: 20
    padding: 60, 40

    Label:
        font_name: "TitleFont.ttf"
        font_size: "60sp"
        text: "Game Title"
        size_hint: 1, 2
    Button:
        background_down: "Blue.jpg"
        background_normal: "Red.jpg"
        font_name: "TitleFont.ttf"
        font_size: "30sp"
        text: "Play"
    Button:
        background_down: "Blue.jpg"
        background_normal: "Red.jpg"
        font_name: "TitleFont.ttf"
        font_size: "30sp"
        text: "LeaderBoards"
    Button:
        background_down: "Blue.jpg"
        background_normal: "Red.jpg"
        font_name: "TitleFont.ttf"
        font_size: "30sp"
        text: "Credits"
    Button:
        background_down: "Blue.jpg"
        background_normal: "Red.jpg"
        font_name: "TitleFont.ttf"
        font_size: "30sp"
        text: "Settings"

此代码生成如下屏幕:Image

我知道我需要使用 on_click 或 on_release 方法,但我不知道如何将它连接到我的 Python 文件中的函数。 我的问题与该站点上的其他问题不同,因为它使用 kv 语言和 Python 而不仅仅是 Python

创建自定义 class,然后通过 root.attribute

访问 class' 属性
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.lang import Builder


Builder.load_string('''

<MyLayout>:
    Button:
        text: 'Try me!'
        on_release: root.button_pressed()

''')


class MyLayout(BoxLayout):

    def button_pressed(self):
        print("Button pressed")


class MyApp(App):

    def build(self):
        return MyLayout()


MyApp().run()