Question

我使用kivy编写程序，我认为它应该可行，但它没有。

代码：

main.py：

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.carousel import Carousel
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.pagelayout import PageLayout
from kivy.uix.scrollview import ScrollView

class rootlayout(BoxLayout):
    pass
class topbar(BoxLayout):
    pass
class body(Carousel):
    pass

class myApp(App):
    def build(self):
        return rootlayout()


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

my.kv：

<rootlayout>:
    height:root.height
    spacing:0
    orientation:"vertical"
    Button:
        size_hint:1,0
    topbar:
    body:

<body>:
    size_hint:1, .9
    onepage:
        id:pp
    ScrollView:
        id:scrollid2
        do_scroll_x:False
        GridLayout:
            height: self.minimum_height
            cols:1
            size_hint_y:None
            Button:
                height:root.height * 2
                size_hint_y:None
    ScrollView:
        id:scrollid3
        do_scroll_x:False
        GridLayout:
            height: self.minimum_height
            cols:1
            size_hint_y:None
            Button:
                height:scrollid3.height * 2
                size_hint_y:None

<topbar>:
    size_hint: 1, .1

    orientation:"horizontal"
    Button:
        size_hint:.9,1
        text:"root"
    test:
        size_hint:.1,1
        text:"root"

<onepage@ScrollView>:
    do_scroll_x:False
    GridLayout:
        height: self.minimum_height
        cols:1
        size_hint_y:None
        Button:
            height:scrollid1.height * 2
            size_hint_y:None
<test@Button>:

错误讯息：

  paul@paul-ThinkPad-Edge-E530:~/myProgram/homework/manufacturingExperience/android/ask/test4$ sudo python main.py
[INFO   ] Kivy v1.8.0
[INFO   ] [Logger      ] Record log in /home/paul/.kivy/logs/kivy_14-11-04_39.txt
[INFO   ] [Factory     ] 157 symbols loaded
[DEBUG  ] [Cache       ] register <kv.lang> with limit=None, timeout=Nones
[DEBUG  ] [Cache       ] register <kv.image> with limit=None, timeout=60s
[DEBUG  ] [Cache       ] register <kv.atlas> with limit=None, timeout=Nones
[INFO   ] [Image       ] Providers: img_tex, img_dds, img_pygame, img_pil, img_gif 
[DEBUG  ] [Cache       ] register <kv.texture> with limit=1000, timeout=60s
[DEBUG  ] [Cache       ] register <kv.shader> with limit=1000, timeout=3600s
[INFO   ] [Text        ] Provider: pygame
[DEBUG  ] [Window      ] Ignored <egl_rpi> (import error)
[INFO   ] [Window      ] Provider: pygame(['window_egl_rpi'] ignored)
[DEBUG  ] [Window      ] Display driver x11
[DEBUG  ] [Window      ] Actual window size: 800x600
[DEBUG  ] [Window      ] Actual color bits r8 g8 b8 a8
[DEBUG  ] [Window      ] Actual depth bits: 24
[DEBUG  ] [Window      ] Actual stencil bits: 8
[DEBUG  ] [Window      ] Actual multisampling samples: 4
[INFO   ] [GL          ] OpenGL version <3.0 Mesa 10.1.3>
[INFO   ] [GL          ] OpenGL vendor <Intel Open Source Technology Center>
[INFO   ] [GL          ] OpenGL renderer <Mesa DRI Intel(R) Ivybridge Mobile >
[INFO   ] [GL          ] OpenGL parsed version: 3, 0
[INFO   ] [GL          ] Shading version <1.30>
[INFO   ] [GL          ] Texture max size <8192>
[INFO   ] [GL          ] Texture max units <16>
[DEBUG  ] [Shader      ] Fragment compiled successfully
[DEBUG  ] [Shader      ] Vertex compiled successfully
[DEBUG  ] [ImagePygame ] Load </usr/lib/python2.7/dist-packages/kivy/data/glsl/default.png>
[INFO   ] [Window      ] virtual keyboard not allowed, single mode, not docked
[DEBUG  ] [App         ] Loading kv <./my.kv>
 Traceback (most recent call last):
   File "main.py", line 22, in <module>
     myApp().run()
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 765, in run
     self.load_kv(filename=self.kv_file)
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 585, in load_kv
     root = Builder.load_file(rfilename)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1444, in load_file
     return self.load_string(data, **kwargs)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1491, in load_string
     parser = Parser(content=string, filename=fn)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1049, in __init__
     self.parse(content)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1126, in parse
     rule.precompile()
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 913, in precompile
     x.precompile()
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 843, in precompile
     self.co_value = compile(value, self.ctx.filename or '<string>', mode)
   File "./my.kv", line 14
     id:pp
       ^
 SyntaxError: invalid syntax

在代码中，我看到测试小部件有效，但是一个页面没有。我使用ubuntu 14.04，kivy 1.8，并从ppa：kivy-team / kivy安装了kivy。谢谢你的帮助！

Answer 1

您的窗口小部件类名称需要以大写字母开头。无论如何，在Python中使用CamelCase命名您的类是标准做法（即RootLayout而不是rootlayout），但是kv解析器没有其他方法可以告诉属性除了小部件。因此，如果声明的第一个字符是小写的，则解析器假定声明属于属性。所以这个：

<body>:
    onepage:
        id:pp

被解释为尝试将onepage小部件的body属性设置为值id:pp，这不是有效的Python表达式。如果您将onepage重命名为OnePage，则可以这样做：

<body>:
    OnePage:
        id:pp

无法在kivy中为动态创建的小部件赋予新属性

1 个答案: