在Tkinter中使用计时器制作GUI？

Question

我试图显示与打印时输出类似的计时器，但只是将输出更新放在同一位置，类似于在gui中创建时钟以查看其自我更新。

我尝试了不同的代码来尝试在GUI工作的地方并获得输出，但是当我将其移到代码中以捕获变量时

from tkinter import *
from tkinter import font
import time
import humanfriendly
from timeit import default_timer as timer
import RPi.GPIO as GPIO
from mfrc522 import SimpleMFRC522 


import RPi.GPIO as GPIO
timeh=0
timem=0
paystat=0



win = Tk()
win2 = Tk()

myFont1=font.Font (family = 'Times New Roman', size = 18, weight = 'bold')
myFont2=font.Font (family = 'Times New Roman', size = 50, weight = 'bold')
font.families()


def add():
    global timem
    global timeh
    print("Time added")
    if paystat==0:
        if timeh<4:
            timem=timem+15
            if timem%60==0:
                timeh=timeh+1
                timem=0
        else: 
            return 0 

    timeDisp1.delete(1.0,END) #clear display
    timeDisp1.insert(END,timem) #append display
    #(END, timem)
    timeDisp2.delete(1.0,END) #clear display
    timeDisp2.insert(END,timeh) #append display
    #(END, timeh)
    return (timeh,timem)

def sub():
    global timem
    global timeh
    print("Time subtracted")
    if paystat==0:
        timem=timem-15
        if timem<0 and timeh!=0:
            timeh=timeh-1
            timem+=60
        if timem<0 and timeh==0:
            timeh=0
            timem=0
   timeDisp1.delete(1.0,END) #clear display
    timeDisp1.insert(END,timem) #append display
    #(END, timem
    timeDisp2.delete(1.0,END) #clear display
    timeDisp2.insert(END,timeh) #append display

    return (timeh,timem)    
def pay(): 
    paystat=1
    reader = SimpleMFRC522()
   try:
        id, text = reader.read()
        print(id)
        print(text)
        if paystat==1:
            win.after(1000,win.destroy)
                timer1 = ''
                timer2= Label(win2, font=('times', 20, 'bold'))
                timer2.pack(fill=BOTH, expand=1)

                def timer():
                        global timeh
                        global timem
                        global timer1
                        timeh1=timeh*3600
                        timem1=timem*60

                        truetime=timeh1+timem1
                        print("Time Expired is:",truetime)
                        start_time=time.time()
                        struct = time.localtime (start_time)

                        print ("Starting Time at:", time.strftime("%X", struct))

                        t = int(time.time())
                        expiration_time = t + truetime
                        difference= round(expiration_time-start_time)
                        struct2= time.localtime (expiration_time)
                        i= timeh1+timem1

                        while i>-1:
                            print(i)
                            letsgo=humanfriendly.format_timespan(i)
                            i-=1
                            time.sleep(1)
                            if letsgo!= timer1:
                            timer1=letsgo
                            letsgo=humanfriendly.format_timespan(i)
                            print("\nTime Left is:",letsgo, "seconds",time.strftime("%X",struct2))
                            timer2.config(text=letsgo)


                timer()
    finally:
    GPIO.cleanup()

time1 = ''
clock = Label(win, font=('times', 20, 'bold'))
clock.pack(fill=BOTH, expand=1)
def tick():
    global time1
    time2 = time.strftime('%H:%M:%S')

    if time2 != time1:
        time1 = time2
        clock.config(text=time2)

    clock.after(200, tick)
tick()

time1 = ''
clock = Label(win2, font=('times', 20, 'bold'))
clock.pack(fill=BOTH, expand=1)
def tick():
    global time1

    time2 = time.strftime('%H:%M:%S')

    if time2 != time1:
        time1 = time2
        clock.config(text=time2)

    clock.after(200, tick)
tick()



win.title("First GUI")
win.geometry('480x320')



addButton = Button(win, text = "+", font = myFont1, command = add, height = 2, width = 4)
addButton.place(x=310, y=50)

subButton = Button(win, text = "-", font = myFont1, command = sub, height = 2, width = 4)
subButton.place(x=85, y=50)

timeDisp1 = Text(win,font=myFont2, height = 1, width = 2) #Time display minutes 
timeDisp1.place(x=235, y=50)

timeDisp2 = Text(win,font=myFont2, height = 1, width = 2) #Time display hours
timeDisp2.place(x=160, y=50)

payButton = Button(win, text = "PAY", font = myFont1, command = pay, height = 2, width = 6)
payButton.place(x=188, y=250)

timeText = Label(win, text = 'ADD DESIRED TIME\n MAX TIME IS 4 HOURS')
timeText.place(x=165, y= 20)

startButton= Button(win,text="Press To Begin Adding Time", font = myFont1, command = lambda : startButton.destroy(), height = 12, width = 40)
startButton.place(x=0, y=0)



#GUI Window 2
win2.title("Second GUI")
win2.geometry ('480x320')

time1Text = Label(win2, text = 'TIME REMAINING')
time1Text.place(x=165, y= 20)





win.mainloop()
win2.mainloop()

这是第二个代码的输出，其中没有捕获时间。

过期时间为：0     开始时间：14:27:36

在工作时，thonny外壳中的打印内容是：

剩余时间为：44分58秒15:59:14

2698

但是当我合并它以捕获第一个gui窗口的输入时，它在我创建的第二个窗口中没有显示任何数据。