无法停止python中的计时器(after和after_cancel)
无法停止python中的计时器(after和after_cancel)
提问于 2021-02-25 18:37:32
我正在尝试在tkinter GUI中创建一个计时器，它在开始按钮上启动，在停止按钮上停止。我正在使用
.after循环计时器，但我不能正确积分.after_取消..。任何建议都将不胜感激。
#import python modules
import time
import math
from tkinter import *
#Create a root window to work in
root = Tk()
root.title("CNT Synthesis Controller") #title of file
#Create global variables to be stored
global var_status
global current_time
global start_time
current_time = 0
#Create Labels
myLabel_Status_T = Label(root, text="Total time elapsed (hrs:min:sec):")
myLabel_Timer = Label(root, text="00:00:00")
#Locate labels
myLabel_Status_T.grid(row=0, column=0)
myLabel_Timer.grid(row=1, column=0)
#Start button function
def Click_Start():
#disable Start Button to prevent re-start
myButton_Start.config(state=DISABLED)
#initiate time = 0 and start timer
start_time = time.time()
global Timer_continue
Timer_continue = True
#Timer function
def Timer():
#determine the amount of time passed since start_time measured
current_time = int(time.time()-start_time)
hour = math.floor(current_time/3600)
minute = math.floor((current_time/60)-(hour*60))
second = math.floor(current_time-(hour*3600)-(minute*60))
#shows time as 00:00:00, i.e. adding in the zeroes where needed
if hour<10:
hour=str("0"+str(hour))
else:
hour=str(hour)
if minute<10:
minute=str("0"+str(minute))
else:
minute=str(minute)
if second<10:
second=str("0"+str(second))
else:
second=str(second)
#print the time to the label myLabel_Timer
myLabel_Timer.config(text= hour + ":" + minute + ":" + second)
#after 1000 ms repeat the Timer function
#while (myButton_Stop['state'] != tk.DISABLED):
#Timer_Object=myLabel_Timer.after(1000,Timer)
if Timer_continue == True:
root.after(1000,Timer)
if Timer_continue == False:
root.after_cancel(Timer)
Timer()
#Stop button function
def Click_Stop():
Timer_continue = False
#disable Stop Button to prevent re-use until program is reset
myButton_Stop.config(state=DISABLED)
#Create Buttons
myButton_Start = Button(root,text="Start CNT Synthesis", padx=40, pady=20, fg="white", bg="green", command=Click_Start)
myButton_Stop = Button(root,text="Stop CNT Synthesis", padx=40, pady=20, fg="white", bg="red", command=Click_Stop)
#Locate buttons
myButton_Start.grid(row=2, column=0)
myButton_Stop.grid(row=2, column=1)
root.mainloop()####----Required添加了文本以使问题“足够长”---#
回答 2
Stack Overflow用户
回答已采纳
发布于 2021-02-26 09:45:26
需要保存由返回的ID.after()并在.after_cancel()停止里面的计时器Click_Stop()功能：
#import python modules
import time
from tkinter import *
#Create a root window to work in
root = Tk()
root.title("CNT Synthesis Controller") #title of file
#Create Labels
myLabel_Status_T = Label(root, text="Total time elapsed (hrs:min:sec):")
myLabel_Timer = Label(root, text="00:00:00")
#Locate labels
myLabel_Status_T.grid(row=0, column=0)
myLabel_Timer.grid(row=1, column=0)
Timer_id = None # used to store the ID returned by .after()
#Start button function
def Click_Start():
#disable Start Button to prevent re-start
myButton_Start.config(state=DISABLED)
#enable Stop Button
myButton_Stop.config(state=NORMAL)
#save the start timer
start_time = time.time()
#Timer function
def Timer():
global Timer_id
#determine the amount of time passed since start_time measured
elapsed = int(time.time()-start_time)
minutes, seconds = divmod(elapsed, 60)
hours, minutes = divmod(minutes, 60)
myLabel_Timer.config(text=f"{hours:02}:{minutes:02}:{seconds:02}")
#after 1000 ms repeat the Timer function
Timer_id = root.after(1000,Timer) # save the after ID
Timer()
#Stop button function
def Click_Stop():
if Timer_id:
root.after_cancel(Timer_id) # cancel the scheduled task
#disable Stop Button to prevent re-use until program is reset
myButton_Stop.config(state=DISABLED)
#enable Start Button
myButton_Start.config(state=NORMAL)
#Create Buttons
myButton_Start = Button(root,text="Start CNT Synthesis", padx=40, pady=20,
fg="white", bg="green", command=Click_Start)
myButton_Stop = Button(root,text="Stop CNT Synthesis", padx=40, pady=20,
fg="white", bg="red", command=Click_Stop, state=DISABLED) # disable stop button initially
#Locate buttons
myButton_Start.grid(row=2, column=0)
myButton_Stop.grid(row=2, column=1)
root.mainloop()Stack Overflow用户
发布于 2021-02-25 18:50:44
错过全局声明：
def Click_Stop():
global Timer_continue
Timer_continue = False页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/66366887
复制相关文章
相似问题
腾讯云开发者
