I am new to Python as well as Kivy, this is my first small project, and don't know what I did wrong, following is the log from pydev(eclipse):
[INFO ] Kivy v1.8.0
[INFO ] [Logger ] Record log in C:\Users\Sudheer\.kivy\logs\kivy_14-06-21_10.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_gif (img_pil ignored)
[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 ] [Cache ] register <kv.loader> with limit=500, timeout=60s
[INFO ] [Loader ] using a thread pool of 2 workers
[DEBUG ] [Cache ] register <textinput.label> with limit=None, timeout=60.0s
[DEBUG ] [Cache ] register <textinput.width> with limit=None, timeout=60.0s
[DEBUG ] [App ] Loading kv <D:\OS Files\workspace\Kal\Src\myclass.kv>
[DEBUG ] [App ] kv <D:\OS Files\workspace\Kal\Src\myclass.kv> not found
[CRITICAL ] App.root must be an _instance_ of Widget
Traceback (most recent call last):
File "D:\OS Files\workspace\Kal\__main__.py", line 9, in <module>
MyClass().run()
File "C:\Kivy180\kivy\kivy\app.py", line 772, in run
raise Exception('Invalid instance in App.root')
Exception: Invalid instance in App.root
Code file structure is as follows:
Codes are as follows: File:main.py
from Src.AppStart import MyClass
if __name__ == '__main__':
MyClass().run()
File:AppStart.py:
from kivy.app import App
from Src.Logins.LoginForm import LoginForm
from kivy.uix.button import Button
class MyClass(App):
'''
classdocs
'''
def build(self):
c=LoginForm
#c=Button(text="Checked")
return c
File:LoginForm.py:
from kivy.uix.gridlayout import GridLayout
from kivy.graphics import Color
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
class LoginForm(GridLayout):
'''
classdocs
'''
def __init__(self, **kwargs):
#kwargs['cols'] = 1
#Layout=GridLayout(cols=2, rows=3, background_color=Color(1,1,1))
self.cols=2
self.rows=3
self.background_color=Color(1,1,1)
IDlbl =Label(text="User ID: ")
PWlbl =Label(text="Password: ")
IDtxtbox = TextInput(text="",multiline=False)
PWtxtbox = TextInput(text="",multiline=False, password=True)
self.add_widget(IDlbl)
self.add_widget(PWlbl)
self.add_widget(IDtxtbox)
self.add_widget(PWtxtbox)
#return Layout
super(LoginForm, self).__init__(**kwargs)
Could you please let me know why is App.root is an invalid instance,
The return value of App.build()
is assigned as App.root
. In your build()
you return a class (LoginForm
) instead of an instance of the class. Simply changing that line in build()
to c = LoginForm()
should fix it.