尝试在Python的Kivy中创建动态按钮类，但获得无效的属性名称

Question

I'm trying this out and I'm wondering why I'm not quite getting it. I tried adding the code, but am getting:

Invalid property name on the line:

  <MyButton@Button>: 

Dynamic class declaration:

<MyButton@Button>:
     text: 'My Button!'
      # .. other Button properties

So the entire bit of code is:

 <GridLayout>
     cols: 4
     row_default_height: 100

 <MyButton@Button>:
     text: 'My Button!'
     # .. other Button properties

MyButton:
    # properties I might want to set that aren't specified in dynamic class   

Answer 1

Judging by your code I see these declarations:

• ' <GridLayout>'
• ' <MyButton@Button>:'

If it's not just a formatting issue here on SO (Ctrl+K for propper formatting), then this will raise an error, because widget/rule declarations are only at the first level ( read: without any characters before < , ' ' is a character too), which means the parser treats the declaration as a property probably because it contains : character or maybe just because it's not at first level, which would mean that such string is either a property or a widget. (or a continuation of the previous line)