Kivy'对象没有属性'错误

Posted 2023-04-18

【中文标题】Kivy\'对象没有属性\'错误

【英文标题】：Kivy 'object has no attribute' ErrorKivy'对象没有属性'错误

【发布时间】：2018-09-01 18:05:56

【问题描述】：

我是 python 和 Kivy 编程的新手，所以遇到了麻烦，可能会在这里提出简单的问题，但现在对我来说是一个很大的障碍。 我正在用 kivy 开发一个 GUI。我有一些 TextInputs 可以获取数值。在所有文本输入之后，我有一个“确定”按钮，它可以获取所有值并处理它们。 我从 .kv 文件中的同一类调用函数时出错。

main.py 文件：

# File name: jwelkreator.py
import kivy
kivy.require('1.7.0')
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.anchorlayout import AnchorLayout

Builder.load_file('simpleForm.kv')
...
...

class JwelKreator(AnchorLayout):
    pass

class JwelKreatorApp(App):
    def build(self):
        return JwelKreator()

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

主kv文件

# File name: jwelkreator.kv
#:kivy 1.7.0
<JwelKreator>:
    AnchorLayout:
        anchor_x: 'left'
        anchor_y: 'top'
        MyLayout:
            id: _tool_box
            size_hint: None,0.75
            width: 300
   ...
   ...

simpleForm.py 用于文本输入。

import kivy

from kivy.app import App
from kivy.lang import Builder
from kivy.config import Config

from kivy.uix.boxlayout import BoxLayout

class LblTxt(BoxLayout):
    pass
class MyLayout(BoxLayout):
    def print_something(self):
        print "Hello"

simpleForm.kv 文本输入布局

<LblTxt@BoxLayout>:
    id:LblTxtid
    orientation: 'horizontal'      
    lblTxtIn: 'default'
    theTxt: iAmTxt
    Label:
        text: root.lblTxtIn
        size_hint: 1,0.5
    TextInput:
        id: iAmTxt  
        multiline: False
        hint_text: "numeric only"           
        input_filter: 'int'
        size_hint: 0.5,None
        height: 30
<MyLayout@BoxLayout>:  
    orientation: 'vertical'

    LblTxt:   
        id: lt0
        lblTxtIn: 'Base Layers'

    LblTxt:   
        id: lt1
        lblTxtIn: 'Base exposer time(ms)'

    LblTxt:   
        id: lt2
        lblTxtIn: 'Min Support Height(mm)'

    LblTxt:   
        id: lt3
        lblTxtIn: 'Support Layers'

    LblTxt:   
        id: lt4
        lblTxtIn: 'Support exposer time(ms)'

    LblTxt:   
        id: lt5
        lblTxtIn: 'Job exposer time(ms)'

    Label:
        text:"Number of Layers"
    Button:
        text: 'OK'
        size_hint: 0.5,None
        height: 30
        on_release: root.print_something()

当我按下“确定”按钮时，属性错误生成。

Traceback (most recent call last):
   File "jwelkreator.py", line 21, in <module>
     JwelKreatorApp().run()
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 600, in run
     runTouchApp()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 454, in runTouchApp
     EventLoop.window.mainloop()
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_pygame.py", line 325, in mainloop
     self._mainloop()
   File "/usr/lib/python2.7/dist-packages/kivy/core/window/window_pygame.py", line 231, in _mainloop
     EventLoop.idle()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 297, in idle
     self.dispatch_input()
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 284, in dispatch_input
     post_dispatch_input(*pop(0))
   File "/usr/lib/python2.7/dist-packages/kivy/base.py", line 253, in post_dispatch_input
     wid.dispatch('on_touch_up', me)
   File "_event.pyx", line 285, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:4184)
   File "/usr/lib/python2.7/dist-packages/kivy/uix/button.py", line 140, in on_touch_up
     self.dispatch('on_release')
   File "_event.pyx", line 281, in kivy._event.EventDispatcher.dispatch (kivy/_event.c:4134)
   File "simpleForm.kv", line 1, in <module>
     <LblTxt@BoxLayout>:
 AttributeError: 'MyLayout' object has no attribute 'print_something'

我被困在这里，没有办法解决它。有什么我想念的吗？

编辑： @eyllanesc：根据你的建议，我已经从我的 kv 类名中删除了 @BoxLayout。当我从 main.kv 调用 MyLayout 时，我的主 .kv 文件出现错误

MyLayout:
            id: _tool_box
            size_hint: None,0.75
            width: 300

错误：

Traceback (most recent call last):
   File "jwelkreator.py", line 21, in <module>
     JwelKreatorApp().run()
   File "/usr/lib/python2.7/dist-packages/kivy/app.py", line 577, in run
     root = self.build()
   File "jwelkreator.py", line 18, in build
     return JwelKreator()
   File "/usr/lib/python2.7/dist-packages/kivy/uix/anchorlayout.py", line 62, in __init__
     super(AnchorLayout, self).__init__(**kwargs)
   File "/usr/lib/python2.7/dist-packages/kivy/uix/layout.py", line 61, in __init__
     super(Layout, self).__init__(**kwargs)
   File "/usr/lib/python2.7/dist-packages/kivy/uix/widget.py", line 163, in __init__
     Builder.apply(self)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1429, in apply
     self._apply_rule(widget, rule, rule)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1534, in _apply_rule
     self._apply_rule(child, crule, rootrule)
   File "/usr/lib/python2.7/dist-packages/kivy/lang.py", line 1496, in _apply_rule
     cls = Factory_get(cname)
   File "/usr/lib/python2.7/dist-packages/kivy/factory.py", line 91, in __getattr__
     raise FactoryException('Unknown class <%s>' % name)
 kivy.factory.FactoryException: Unknown class <MyLayout>

【参考方案1】：

问题

您收到 AttributeError: 'MyLayout' object has no attribute 'print_something'，因为它找不到函数 print_something。 p>

解决方案

详情请参阅解释、示例和输出。

说明

jwelkreator.py

添加 from simpleForm import MyLayout 删除 Builder.load_file('simpleForm.kv')

jwelkreator.kv

添加 #:include simpleForm.kv 以包含外部 kivy 文件。

include <file> - Kivy Language

包括一个外部 kivy 文件。这允许您将复杂的小部件拆分为它们自己的文件。

simpleForm.py

您不必定义动态类，LblTxt(BoxLayout)，因为您已经在 kv 文件中定义了它。

Dynamic Classes - Programming Guide » Kv language

这个类是由这个规则的声明创建的，它继承自 Button 类，允许我们更改默认值并为其所有实例创建绑定，而无需在 Python 端添加任何新代码。

simpleform.kv

由于在Python脚本simpleForm.py中，你已经定义了类MyLayout是BoxLayout的，你不要在kv文件中继承它。将 替换为

示例

jwealkreator.py

​​>

from kivy.app import App
from kivy.uix.anchorlayout import AnchorLayout
from simpleForm import MyLayout


class JwelKreator(AnchorLayout):
    pass


class JwelKreatorApp(App):

    def build(self):
        return JwelKreator()


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

jwealkreator.kv

# File name: jwelkreator.kv
#:kivy 1.10.0
#:include simpleform.kv

<JwelKreator>:
    anchor_x: 'left'
    anchor_y: 'top'
    MyLayout:
        id: _tool_box
        size_hint: None,0.75
        width: 300

simpleForm.py

​​>

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout


class MyLayout(BoxLayout):
    def print_something(self):
        print("Hello")


class SimpleFormApp(App):

    def build(self):
        return MyLayout()


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

simpleform.kv

#:kivy 1.10.0

<LblTxt@BoxLayout>:
    id:LblTxtid
    orientation: 'horizontal'
    lblTxtIn: 'default'
    theTxt: iAmTxt
    Label:
        text: root.lblTxtIn
        size_hint: 1,0.5
    TextInput:
        id: iAmTxt
        multiline: False
        hint_text: "numeric only"
        input_filter: 'int'
        size_hint: 0.5,None
        height: 30

<MyLayout>:
    orientation: 'vertical'

    LblTxt:
        id: lt0
        lblTxtIn: 'Base Layers'

    LblTxt:
        id: lt1
        lblTxtIn: 'Base exposer time(ms)'

    LblTxt:
        id: lt2
        lblTxtIn: 'Min Support Height(mm)'

    LblTxt:
        id: lt3
        lblTxtIn: 'Support Layers'

    LblTxt:
        id: lt4
        lblTxtIn: 'Support exposer time(ms)'

    LblTxt:
        id: lt5
        lblTxtIn: 'Job exposer time(ms)'

    Label:
        text:"Number of Layers"
    Button:
        text: 'OK'
        size_hint: 0.5,None
        height: 30
        on_release: root.print_something()

输出

【讨论】：

非常感谢您的解释。它对我有用！ #:include simpleform.kv 给了我无效的指令错误，但我已经在我的主 py 文件中使用 Builder 添加了 .kv，所以它可以工作。非常感谢。