我正在制作一个应用程序。据我所知，我正在做正确的事情，但仍然收到此错误
字= self.search_box.text AttributeError：＆＃39; NoneType＆＃39;对象没有属性＆＃39; text＆＃39;
我检查过拼写错误和其他常见错误仍然无效。
继承人代码 -
import kivy
kivy.require('1.10.0')
from kivy.uix.stacklayout import StackLayout
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.app import App
from kivy.uix.popup import Popup
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.lang import Builder
from kivy.properties import ObjectProperty
from kivy.uix.textinput import TextInput
from kivy.properties import StringProperty
import json
Builder.load_file('VocabularyJournal.kv')
class MenuPage(Screen):
pass
class DisplayPage(Screen):
search_box= ObjectProperty()
label_maening=StringProperty()
label_synonym=StringProperty()
label_ant=StringProperty()
label_sentence=StringProperty()
def __init__(self, **kwargs):
super(DisplayPage,self).__init__(**kwargs)
with open('vocab_words.json') as rfile:
data=json.load(rfile)
word=self.search_box.text #the error occurred here
for value in data:
if value['word']==word:
self.label_maening=value['meaning']
self.label_synonym=value['synonym']
self.label_ant=value['antonyms']
self.label_sentence=value['sentence']
class WordInsertPage(Screen):
pass
class NewWordPage(Screen):
word_box = ObjectProperty()
meaning_box = ObjectProperty()
synonym_box = ObjectProperty()
ant_box = ObjectProperty()
sentence_box = ObjectProperty()
def saving_data(self):
with open('vocab_words.json') as rfile:
data=json.load(rfile)
entry={'word': self.word_box.text, 'meaning': self.meaning_box.text, 'synonym': self.synonym_box.text, 'antonyms': self.ant_box.text, 'sentence': self.sentence_box.text}
data.append(entry)
with open('vocab_words.json','w') as wfile:
json.dump(data,wfile,indent=4)
class FlashCard(Screen):
pass
class WordGroups(Screen):
pass
class Manager(ScreenManager):
pass
class VocabularyJournalApp(App):
def build(self):
return Manager()
object = VocabularyJournalApp()
object.run()
继承人kv代码 -
<Manager>:
MenuPage:
name: 'menu'
WordInsertPage:
name: 'insertword'
NewWordPage:
name: 'newword'
FlashCard:
name: 'flashcard'
WordGroups:
name: 'wordgroup'
DisplayPage:
name: 'display'
<MenuPage>:
Label:
text: "Vocabulary Journal"
size_hint: .90,.10
StackLayout:
orientation: 'tb-rl'
spacing: 10
padding: 10
Button:
text: 'Search'
size_hint: None,.20
width: 130
background_down:'darkgrey.png'
on_press: root.manager.current='insertword'
Button:
text: 'New Word'
size_hint: None,.20
width: 130
background_down:'darkgrey.png'
on_press: root.manager.current='insertword'
Button:
text: 'Flash Cards'
size_hint: None,.20
width: 130
background_down:'darkgrey.png'
on_press: root.manager.current='flashcard'
Button:
text: 'Word Groups'
size_hint: None,.20
width: 130
background_down:'darkgrey.png'
on_press: root.manager.current='wordgroup'
<WordInsertPage>:
FloatLayout:
Button:
text: "New Word"
on_press: root.manager.current='newword'
font_size: 30
color: 0,0,0,1
size_hint: .2, .1
pos_hint: {"center_x": .5, "center_y": 0.3}
background_down: 'darkgrey.png'
Button:
text: "search word"
on_press: root.manager.current='display'
font_size: 30
color: 0,0,0,1
size_hint: .2, .1
pos_hint: {"center_x": .5, "center_y": 0.5}
background_down: 'darkgrey.png'
Button:
text: 'Flash Cards'
on_press: root.manager.current="flashcard"
font_size: 30
color: 0,0,0,1
size_hint: .2, .1
pos_hint: {"center_x": .5, "center_y": 0.7}
background_down: 'darkgrey.png'
<NewWordPage>:
id: refer_to_it
word_box: word_input
meaning_box: meaning_input
synonym_box: Synonym_input
ant_box: ant_input
sentence_box: sentence_input
StackLayout:
orientation: 'tb-rl'
spacing: 10
padding: 90
TextInput:
text: "write your word here"
color: 1,1,1,1
id: word_input
width: 300
size_hint: None, .10
TextInput:
text: "write meaning of your word here"
color: 1,1,1,1
id: meaning_input
width: 600
size_hint: None, .20
TextInput:
text: "write Synonyms of your word here"
color: 1,1,1,1
id: Synonym_input
width: 600
size_hint: None, .20
TextInput:
text: "write antonyms of your text here"
color: 1,1,1,1
id: ant_input
width: 600
size_hint: None, .20
TextInput:
text: "write a sentence based on your word here"
color: 1,1,1,1
id: sentence_input
width: 600
size_hint: None, .20
Button:
text: 'Save'
size_hint: None,.10
width: 130
background_down:'darkgrey.png'
on_press: refer_to_it.saving_data()
<DisplayPage>:
search_box: search_text # search_box is the reference to the textinput in py file
BoxLayout:
size_hint_y: None
height: '48dp'
TextInput:
text:'enter the word you wanna search here'
id: search_text
ToggleButton:
id: tog
text: 'Horizontal'
group: 'accordion'
state: 'down'
ToggleButton:
text: 'Vertical'
group: 'accordion'
Accordion:
orientation: 'horizontal' if tog.state == 'down' else 'vertical'
AccordionItem:
title:'meaning'
Label:
text: root.label_maening
text_size: self.width, None
AccordionItem:
title:'Synonym'
Label:
text: root.label_synonym
text_size: self.width, None
AccordionItem:
title:'Antonym'
Label:
text: root.label_ant
text_size: self.width, None
AccordionItem:
title:'Sentence'
Label:
text: root.label_sentence
text_size: self.width, None
答案 0 :(得分：1)
问题是由于子进程没有卡在父进程的构造函数中引起的，它会在一段时间之后执行，所以search_box在构造函数中将为None，解决方法是在完成构造函数后立即执行它时钟：
from kivy.clock import Clock
class DisplayPage(Screen):
search_box= ObjectProperty()
label_maening=StringProperty()
label_synonym=StringProperty()
label_ant=StringProperty()
label_sentence=StringProperty()
def __init__(self, **kwargs):
super(DisplayPage,self).__init__(**kwargs)
Clock.schedule_once(self.callback)
def callback(self, dt):
with open('vocab_words.json') as rfile:
data=json.load(rfile)
word=self.search_box.text #the error occurred here
for value in data:
if value['word']==word:
self.label_maening=value['meaning']
self.label_synonym=value['synonym']
self.label_ant=value['antonyms']
self.label_sentence=value['sentence']