我是Kivy的菜鸟，所以我现在的问题如下： 我一直有这个属性错误，我知道我错过了什么，所以在继续我的应用程序之前我需要先理解这个：
main.kv：
MainRoot:
<MainRoot>:
padding: 10
spacing: 10
canvas:
Color:
rgb: .2, .2, .2
Rectangle:
pos: self.pos
size: self.size
ClientArea:
ProductArea:
DisplayArea:
<ProductArea>:
text_input: text_input_view
# search_results: search_results_view
minimum_width: '480dp'
orientation:'vertical'
canvas:
Color:
rgb: .25, .25, .25
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
orientation: 'horizontal'
size_hint_y: None
height: '30dp'
TextInput:
id: text_input_view
size_hint_x: 90
focus: True
multiline: False
on_text: root.search()
Button:
text: 'Search'
size_hint_x: 25
on_press: root.search()
ListView:
# id: search_results_view
# adapter: root.dict_adapter
BoxLayout:
orientation: 'horizontal'
size_hint_y: None
height: '50dp'
Button:
size_hint_x: 10
text: '-5'
Button:
size_hint_x: 15
text: '-'
Button:
size_hint_x: 50
text: 'Add to cart'
Button:
size_hint_x: 15
text: '+'
Button:
size_hint_x: 10
text: '+5'
ListView:
<ClientArea>:
orientation:'vertical'
canvas:
Color:
rgb: .22, .22, .22
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
orientation: 'horizontal'
size_hint_y: None
height: '30dp'
TextInput:
id: search_client_view
size_hint_x: 90
focus: True
multiline: False
Button:
text: 'Search'
size_hint_x: 25
ListView:
BoxLayout:
orientation: 'horizontal'
size_hint_y: None
height: '30dp'
Button:
text: 'Select'
BoxLayout:
Label:
text: 'Client Display'
<DisplayArea>:
orientation:'vertical'
canvas:
Color:
rgb: .22, .22, .22
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
canvas:
Color:
rgb: .4, .4, .4
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
canvas:
Color:
rgb: .35, .35, .35
Rectangle:
pos: self.pos
size: self.size
BoxLayout:
canvas:
Color:
rgb: .4, .4, .4
Rectangle:
pos: self.pos
size: self.size
和main.py：
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.properties import ObjectProperty, ListProperty, DictProperty, BooleanProperty, StringProperty
from kivy.uix.label import Label
from kivy.adapters.listadapter import ListAdapter
from kivy.adapters.dictadapter import DictAdapter
from kivy.uix.textinput import TextInput
from kivy.uix.listview import ListItemButton, CompositeListItem, ListItemLabel
from kivy.config import Config
from db_handlers import DbQueries as dbq
Config.set('graphics', 'height', '900')
Config.set('graphics', 'width', '1200')
Config.set('graphics', 'minimum_height', '940')
Config.set('graphics', 'minimum_width', '1400')
class ClientArea(BoxLayout):
pass
class ProductArea(BoxLayout):
#search display properties and variables
text_input = ObjectProperty()
search_results = ObjectProperty()
#cart properties and variables
dict_adapter = ObjectProperty({'': ''})
def __init__(self, **kwargs):
super(ProductArea, self).__init__(**kwargs)
self.search(self.text_input)
def search(self, txt_input):
print('Hello' + txt_input.text)
class ProductListButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint_y'] = None
kwargs['height'] = '55dp'
kwargs['text_size'] = (self.width*3, None)
kwargs['deselected_color'] = [.4, .4, .4, 1]
kwargs['selected_color'] = [.7, .9, .7, 1]
super(ProductListButton, self).__init__(**kwargs)
class CartButton(CompositeListItem):
def __init__(self, **kwargs):
kwargs['size_hint_y'] = None
kwargs['height'] = '60dp'
super(CartButton, self).__init__(**kwargs)
class ProductButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint'] = (1, 1)
kwargs['height'] = self.height*2
kwargs['text_size'] = (self.width*2, None)
kwargs['deselected_color'] = [.8, .8, .8, 1]
kwargs['selected_color'] = [.4, .4, .4, 1]
super(ProductButton, self).__init__(**kwargs)
class PriceButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint'] = (None, 1)
kwargs['width'] = "80dp"
kwargs['deselected_color'] = [.8, .8, .8, 1]
kwargs['selected_color'] = [.4, .4, .4, 1]
super(PriceButton, self).__init__(**kwargs)
class QuantityButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint'] = (None, 1)
kwargs['width'] = "50dp"
kwargs['deselected_color'] = [.8, .8, .8, 1]
kwargs['selected_color'] = [.4, .4, .4, 1]
super(QuantityButton, self).__init__(**kwargs)
class AddQuantityButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint'] = (None, 1)
kwargs['width'] = "40dp"
kwargs['deselected_color'] = [.7, .9, .7, 1]
kwargs['selected_color'] = [.7, .9, .7, 1]
super(AddQuantityButton, self).__init__(**kwargs)
class SubtractQuantityButton(ListItemButton):
def __init__(self, **kwargs):
kwargs['size_hint'] = (None, 1)
kwargs['width'] = "40dp"
kwargs['deselected_color'] = [.9, .7, .7, 1]
kwargs['selected_color'] = [.9, .7, .7, 1]
super(SubtractQuantityButton, self).__init__(**kwargs)
class DisplayArea(BoxLayout):
pass
class MainRoot(GridLayout):
def __init__(self, **kwargs):
kwargs['cols'] = 3
super(MainRoot, self).__init__(**kwargs)
class MainApp(App):
def build(self):
return MainRoot()
if __name__ == '__main__':
MainApp().run()
错误：
File "/Users/mac/Desktop/Pharma_dev/v002/main.py", line 35, in __init__
self.search(self.text_input)
File "/Users/mac/Desktop/Pharma_dev/v002/main.py", line 39, in search
print('Hello' + txt_input.text)
AttributeError: 'NoneType' object has no attribute 'text'