如何访问 Kivy 文件中的全局变量？

Question

我有一个名为 Tiles 的全局变量，我想将 TreasureHuntGrid class 中的列数设置到 kivy 文件中。

Main.py

Tiles = 5
class TreasureHuntGrid(GridLayout):
    global Tiles

.kv

<TreasureHuntGrid>:
cols: #Don't know what should I put in here

Answer 1

Globals are evil。如果您想从任何小部件访问变量，最好将其放入 Application class，因为您的程序中只有一个实例：

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.lang import Builder

Builder.load_string("""
<MyWidget>:
    cols: app.tiles
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
""")

class MyWidget(GridLayout):
    pass

class MyApp(App):
    tiles = 5
    def build(self):
        return MyWidget()

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

话虽如此，如果您确实需要，您可以像这样访问全局变量：

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.lang import Builder

tiles = 5

Builder.load_string("""
#: import tiles __main__.tiles

<MyWidget>:
    cols: tiles
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
    Label:
        text: "test"
""")

class MyWidget(GridLayout):
    pass

class MyApp(App):
    def build(self):
        return MyWidget()

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

如何访问 Kivy 文件中的全局变量？

How to access a global var in Kivy file?

python-2.7

kivy