Question

我正在尝试通过单击按钮更新Python中标签的内容。对于每次单击，将引发计数器，并且标签的值将由计数器（j）的当前值更新。这是代码：

import time 
import random
import MySQLdb
from Tkinter import *
j=0

def PrintNumber():
    global j
    j+=1
    print j
    return      

mgui=Tk()
mgui.geometry('200x200')
mgui.title('Queue System')

st = Button(mgui, text="Next Customer", command = PrintNumber)
st.pack()
f = PrintNumber()
label = Label(mgui, text=f)
label.pack()

mgui.mainloop()

请善待，我是Python新手。：）

Answer 1

您可以使用Tkinter variable class实例来保存值。如果将textvariable窗口小部件的Label选项分配给变量类实例，它将在实例值更改时自动更新。这是一个例子：

from Tkinter import *


root = Tk()

var = IntVar() # instantiate the IntVar variable class
var.set(0)     # set it to 0 as the initial value

# the button command is a lambda expression that calls the set method on the var,
# with the var value (var.get) increased by 1 as the argument    
Button(root, text="Next Customer", command=lambda: var.set(var.get() + 1)).pack()

# the label's textvariable is set to the variable class instance
Label(root, textvariable=var).pack()

mainloop()

Answer 2

您可以使用PrintNumber()更改响应命令（在本例中为label.config()）的函数中的标签文本，例如：

from tkinter import *

def PrintNumber():
    global j,label
    j+=1
    label.config(text=str(j))
    return     

j = 0

mgui=Tk()
mgui.geometry('200x200')
mgui.title('Queue System')

st = Button(mgui, text="Next Customer", command = PrintNumber)
st.pack()
label = Label(mgui, text=str(j))
label.pack()
mgui.mainloop()

Answer 3

这是你可以做到的另一种方式

import time 
import random
import MySQLdb
from Tkinter import *


def PrintNumber(label):
    PrintNumber.counter += 1 #simulates a static variable
    print PrintNumber.counter
    label.configure(text=str(PrintNumber.counter)) #you update label here

mgui=Tk()
mgui.geometry('200x200')
mgui.title('Queue System')

PrintNumber.counter = 0 #add an attribute to a function and use it as a static variable

label = Label(mgui) #create label

#pass the label as parameter to your function using lambda notation
st = Button(mgui, text="Next Customer", command=lambda label=label:PrintNumber(label))
st.pack()
label.pack()

mgui.mainloop()

使用Python更新标签内容

3 个答案: