我对Python和Kivy都是新手，这是我的第一个小项目，不知道我做错了什么，下面是pydev(eclipse)的日志：[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 with limit=None, timeout=Nones
[DEBUG ] [Cache ] register with limit=None, timeout=60s
[DEBUG ] [Cache ] register with limit=None, timeout=Nones
[INFO ] [Image ] Providers: img_tex, img_dds, img_pygame, img_gif (img_pil ignored)
[DEBUG ] [Cache ] register with limit=1000, timeout=60s
[DEBUG ] [Cache ] register with limit=1000, timeout=3600s
[INFO ] [Text ] Provider: pygame
[DEBUG ] [Cache ] register with limit=500, timeout=60s
[INFO ] [Loader ] using a thread pool of 2 workers
[DEBUG ] [Cache ] register with limit=None, timeout=60.0s
[DEBUG ] [Cache ] register with limit=None, timeout=60.0s
[DEBUG ] [App ] Loading kv
[DEBUG ] [App ] 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
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
代码文件结构如下：
代码如下：
文件：main.pyfrom Src.AppStart import MyClass
if name == ‘main‘:
MyClass().run()
文件：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
文件：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)
你能告诉我为什么App.root是一个无效的实例吗
Original: https://blog.csdn.net/weixin_29374899/article/details/113638678
Author: 滴水吞舟
Title: python kivy实例_Kivy:应用程序中的实例无效。
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