如何动态更改 Tkinter 中的标签

Question

我正在尝试编写一个计时器，它应该动态更改标签并显示时间，但标签仅在计数器函数完成工作时才会更改，有人知道我如何做到这一点，或者我只有一种方法 - 异步

这是我的代码（请不要笑），如果你知道如何通过异步方式解决这个问题，请告诉我

import tkinter
from tkinter import *
from PIL import Image, ImageTk
import time


def counter(timer_sum):
    start_time = time.time()
    time.sleep(timer_sum)
    end_time = time.time()
---------------
# here 
def change(hours,minutes,seconds):
    time_counter_label.config(text=f'{hours}:{minutes}:{seconds}')
--------------
def timer_function_start():

    count_time = input_timer.get()
    hours_box = int(spin_box_time_hours.get()) * 3600
    minute_box = int(spin_box_time_minuts.get()) * 60
    second_box = int(spin_box_time_second.get())
    timer_sum = hours_box + minute_box + second_box

    time_counter_label.config(text=f'{spin_box_time_hours.get()}:{spin_box_time_minuts.get()}:{spin_box_time_second.get()}')

    for item in range(timer_sum,0,-1):
        hours = int(item /3600) % 60
        minutes = int(item / 60) % 60
        seconds = item % 60
        print(f'{hours}:{minutes}:{seconds}')
        change(hours,minutes,seconds)
        time.sleep(1)


    split_count = count_time.split(':')


    # counter(timer_sum)

    print("finish")


mainWindow = Tk()
mainWindow.minsize(300, 620)
timerImage = Image.open('img/timer.png')
timerImage = ImageTk.PhotoImage(timerImage)

label_name = tkinter.Label(text='Timer')
label_name.pack()
label_name.config(height=3, width=4, font=("Arial", 24))

image_label = tkinter.Label(mainWindow, image=timerImage)
image_label.config(height=220, width=200)
image_label.pack()

button_timer_start = tkinter.Button(text='Start', command=timer_function_start)
button_timer_start.config(width=4, height=2)
button_timer_start.pack(pady=8)

button_timer_stop = tkinter.Button(text='Stop')
button_timer_stop.config(width=4, height=2)
button_timer_stop.pack()

time_counter_label = tkinter.Label(text='00:00:00')
time_counter_label.config(font=('Arial', 22))
time_counter_label.pack(pady=10)

timer_label = tkinter.Label(mainWindow, text="Enter Time")
timer_label.config(height=3, width=7)
timer_label.pack()

input_timer = tkinter.Entry()
input_timer.pack()

list_time_hours = list(map(lambda x: x, range(0, 24 + 1)))
list_time_minit = list(map(lambda x: x, range(0, 60 + 1)))
list_time_second = list(map(lambda x: x, range(0, 60 + 1)))

spin_box_time_hours = tkinter.Spinbox(mainWindow, values=list_time_hours)
spin_box_time_hours.pack(side=tkinter.LEFT, padx=20)
spin_box_time_hours.config(width=3)
spin_box_time_minuts = tkinter.Spinbox(mainWindow, values=list_time_minit)
spin_box_time_minuts.pack(side=tkinter.LEFT, padx=20)
spin_box_time_minuts.config(width=3)
spin_box_time_second = tkinter.Spinbox(mainWindow, values=list_time_second)
spin_box_time_second.pack(side=tkinter.LEFT, padx=20)
spin_box_time_second.config(width=3)

mainWindow.mainloop()

Answer 1

如果您正在开发 tkinter 应用程序并需要定期更新 UI，请不要使用

time.sleep()

。它会阻塞主线程，从而阻止 UI 在睡眠结束之前更新。相反，请使用 tkinter 中的

after()

方法。这会安排在指定时间后调用一个函数，而不会阻塞主线程。

要使其正常工作，请像这样修改您的

timer_function_start

函数：

def timer_function_start():
   # ... your existing setup code for timer_sum ...
   countdown(timer_sum)

def countdown(time_left):
   if time_left > 0:
      hours = int(time_left / 3600) % 60
      minutes = int(time_left / 60) % 60
      seconds = time_left % 60
      time_counter_label.config(text=f'{hours:02d}:{minutes:02d}:{seconds:02d}')
      # Schedule the countdown function to be called after 1000ms (1 second)
      mainWindow.after(1000, countdown, time_left - 1)
   else:
      print("finish")