正确使用 Kivy 的 .kv 文件并将它们导入 Python 脚本

问题描述

我正在关注

有谁知道我做错了什么?这些是我对 /dev/input/event6

的权限

crwxrwxr-- 1 根输入 13, 2011 年 9 月 70 日 23:47/dev/input/event6

非常感谢！

解决方案

根据

I am following tutorials for Kivy and I haven't been able to properly load properties from .kv files. For some reason, I am able to sometimes pull .kv files via a for kv in listdir(kv_path): Builder.load_file(kv_path+kv), but I can't do it by simply putting the kv files in the same root directory and letting it "import by itself?"

As an example, when using the files:
main.py

from kivy.app import App  
from kivy.uix.label import Label   
from kivy.uix.widget import Widget  

class Widgets(Widget):
    pass
class SimpleKivy3(App):
    def build(self):
        return Widgets()

if __name__ == "__main__":
    SimpleKivy3().run()

SimpleKivy3.kv

<Button>:
    font_size: 40
    size: 170,75
    color: 0,1,0,1

<Widgets>:
    Button:
        pos: root.x, root.top - self.height
        text: "Kivy"

    Button:
        pos: 170,0
        text: "Tutorials"

I obtain the following output on my Terminal:

$ python main.py 
[INFO   ] [Logger      ] Record log in /home/nickshu/.kivy/logs/kivy_18-09-12_58.txt
[INFO   ] [Kivy        ] v1.11.0.dev0, git-038acbf, 20180912
[INFO   ] [Python      ] v3.6.5 |Anaconda, Inc.| (default, Apr 29 2018, 16:14:56) 
[GCC 7.2.0]
[INFO   ] [Factory     ] 195 symbols loaded
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_sdl2, img_pil, img_gif (img_ffpyplayer ignored)
[INFO   ] [Text        ] Provider: sdl2
[INFO   ] [Window      ] Provider: sdl2(['window_egl_rpi'] ignored)
[INFO   ] [GL          ] Using the "OpenGL" graphics system
[INFO   ] [GL          ] Backend used <gl>
[INFO   ] [GL          ] OpenGL version <b'3.0 Mesa 18.0.5'>
[INFO   ] [GL          ] OpenGL vendor <b'Intel Open Source Technology Center'>
[INFO   ] [GL          ] OpenGL renderer <b'Mesa DRI Intel(R) HD Graphics P630 (Kaby Lake GT2) '>
[INFO   ] [GL          ] OpenGL parsed version: 3, 0
[INFO   ] [GL          ] Shading version <b'1.30'>
[INFO   ] [GL          ] Texture max size <16384>
[INFO   ] [GL          ] Texture max units <32>
[INFO   ] [Window      ] auto add sdl2 input provider
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[INFO   ] [ProbeSysfs  ] device match: /dev/input/event6
[INFO   ] [MTD         ] Read event from </dev/input/event6>
[INFO   ] [Base        ] Start application main loop
[INFO   ] [MTD         ] </dev/input/event6> range position X is 1266 - 5676
[INFO   ] [MTD         ] </dev/input/event6> range position Y is 1094 - 4762
[INFO   ] [MTD         ] </dev/input/event6> range touch major is 0 - 0
[INFO   ] [MTD         ] </dev/input/event6> range touch minor is 0 - 0
[INFO   ] [MTD         ] </dev/input/event6> range pressure is 0 - 255
[INFO   ] [MTD         ] </dev/input/event6> axes invertion: X is 0, Y is 0
[INFO   ] [MTD         ] </dev/input/event6> rotation set to 0

The following window shows!

Does anyone know what am I doing wrong? These are my permissions for /dev/input/event6

crwxrwxr-- 1 root input 13, 70 Sep 11 23:47 /dev/input/event6

Thank you very much!

解决方案

According to the docs you have 2 possibilities:

1.

By name convention:

Kivy looks for a Kv file with the same name as your App class in lowercase, minus "App" if it ends with ‘App’ e.g:

MyApp -> my.kv

If this file defines a Root Widget it will be attached to the App’s root attribute and used as the base of the application widget tree.

So you must change the name of the .kv to lowercase, and change the name of class App to end in App:

simplekivy3.kv

<Button>:
    font_size: 40
    size: 170,75
    color: 0,1,0,1

<Widgets>:
    Button:
        pos: root.x, root.top - self.height
        text: "Kivy"

    Button:
        pos: 170,0
        text: "Tutorials"

*.py

from kivy.app import App  
from kivy.uix.widget import Widget  

class Widgets(Widget):
    pass

class SimpleKivy3App(App):
    def build(self):
        return Widgets()

if __name__ == "__main__":
    SimpleKivy3App().run()

---

2.

Builder: You can tell Kivy to directly load a string or a file. If this string or file defines a root widget, it will be returned by the method:

Builder.load_file('path/to/file.kv')

from kivy.app import App   
from kivy.uix.widget import Widget  
from kivy.lang import Builder


class Widgets(Widget):
    pass

Builder.load_file('SimpleKivy3.kv')


class SimpleKivy3(App):
    def build(self):
        return Widgets()


if __name__ == "__main__":
    SimpleKivy3().run()