问题
I'm new to python and Kivy programming so getting trouble and may be asking simple question here, but its a big hurdle for me now. I am developing a GUI with kivy. I have some TextInputs which get numeric value. after all text inputs , I have a 'OK' button which gets all value and process them. I'm getting error in calling the function from same class in .kv file.
main.py file:
# 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()
main kv file
# 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 for text inputs.
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 TextInput Layout
<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()
While I press 'OK' button, attribute Error Generated.
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'
I am stuck here and not getting way to solve it. Is there anything I'm missing?
EDIT: @eyllanesc: as per your suggestion, I've removed @BoxLayout from my kv class name. I'm getting error from my main .kv file as I'm calling MyLayout from main.kv
MyLayout:
id: _tool_box
size_hint: None,0.75
width: 300
ERROR:
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>
回答1:
Problem
You are getting AttributeError: 'MyLayout' object has no attribute 'print_something' because it cannot find the function, print_something.
Solution
Please refer to the explanations, example and output for details.
Explanations
jwelkreator.py
- Add from simpleForm import MyLayout
- Remove Builder.load_file('simpleForm.kv')
jwelkreator.kv
Add #:include simpleForm.kv to include an external kivy file.
include <file> - Kivy Language
Includes an external kivy file. This allows you to split complex widgets into their own files.
simpleForm.py
You don't have to define the dynamic class, LblTxt(BoxLayout) since you have it defined in your kv file.
Dynamic Classes - Programming Guide » Kv language
This class, created just by the declaration of this rule, inherits from the Button class and allows us to change default values and create bindings for all its instances without adding any new code on the Python side.
simpleform.kv
Since in the Python script, simpleForm.py, you have already defined class MyLayout is of BoxLayout, you don't to inherit it in the kv file. Replace <MyLayout@BoxLayout> with <MyLayout>
Example
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()
Output
来源：https://stackoverflow.com/questions/49443284/kivy-object-has-no-attribute-error