問題描述

Python/Kivy 的新手嘗試構建一個帶有輸入框、ok 按鈕和一個標簽的測試應用程序，該標簽在單擊 ok 按鈕時應該更改文本.但相反，我得到'NameError:全局名稱'txt1'未定義'.我做錯了什么?

New to Python/Kivy trying to build a test app with an input box, an ok button and a label that should change text when the ok button is clicked. But instead I get 'NameError: global name 'txt1' is not defined'. What am I doing wrong?

# import Kivy
import kivy
import random

from kivy.app import App
from kivy.uix.button import Button
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput

# my app
class MyApp(App):
# layout
    def build(self):
        layout = BoxLayout(padding=10, orientation='vertical')
        btn1 = Button(text="OK")
        btn1.bind(on_press=self.buttonClicked)
        layout.add_widget(btn1)
        lbl1 = Label(text="test")
        layout.add_widget(lbl1)
        txt1 = TextInput(text='', multiline=False)
        layout.add_widget(txt1)
        return layout

# button click function
    def buttonClicked(self,btn):
        lbl1.text = "You wrote " + txt1.text

# run app
if __name__ == "__main__":
    MyApp().run()

推薦答案

使用self.txt1, self.lbl1等..

class MyApp(App):
# layout
    def build(self):
        layout = BoxLayout(padding=10, orientation='vertical')
        btn1 = Button(text="OK")
        btn1.bind(on_press=self.buttonClicked)
        layout.add_widget(btn1)
        self.lbl1 = Label(text="test")
        layout.add_widget(self.lbl1)
        self.txt1 = TextInput(text='', multiline=False)
        layout.add_widget(self.txt1)
        return layout

# button click function
    def buttonClicked(self,btn):
        self.lbl1.text = "You wrote " + self.txt1.text

# run app
if __name__ == "__main__":
    MyApp().run()
 # join all items in a list into 1 big string

使用:

def buttonClicked(self,btn):
        lbl1.text = "You wrote " + txt1.text <- only exists in the build method

這篇關于在 Kivy 應用程序中獲取文本輸入值的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！