Python-tkinter画布中的倒计时

Question

您好，我想在一个子例程中创建一个倒计时，然后显示在画布上。我不完全确定从哪里开始，我已经做了一些研究，并且能够随着时间的推移做一个。sleep（x）函数，但是那个方法冻结了整个程序，这不是我想要的。我也在这里查找了关于计时器的其他问题，并试图将它们合并到我的程序中，但我还没有取得任何成功。

我想创建一个倒计时计时器，它从60秒开始倒计时，并显示在画布上，然后让它在计时器达到0时执行一些操作。

有人能指点我正确的方向吗？

提前谢谢。

编辑：有了这些建议，我试着把它们放进程序中，但运气不太好。

不确定这段代码中是否有重大错误，或者这只是一个简单的错误。 当我运行它时得到的错误低于代码。

这是我希望计时器进入的代码部分：

def main(): #First thing that loads when the program is executed.
   global window
   global tkinter
   global canvas
   global cdtimer
   window = Tk()
   cdtimer = 60
   window.title("JailBreak Bob")

   canvas = Canvas(width = 960, height = 540, bg = "white")
   photo = PhotoImage(file="main.gif")
   canvas.bind("<Button-1>", buttonclick_mainscreen)
   canvas.pack(expand = YES, fill = BOTH)
   canvas.create_image(1, 1, image = photo, anchor = NW)
   window.mainloop()

def buttonclick_mainscreen(event):
   pressed = ""

   if event.x >18 and event.x <365 and event.y > 359 and event.y < 417 : pressed = 1 
   if event.x >18 and event.x <365 and event.y > 421 and event.y < 473 : pressed = 2 
   if event.x >18 and event.x <365 and event.y > 477 and event.y < 517 : pressed = 3 

   if pressed == 1 :
     gamescreen()
   if pressed == 2 :
     helpscreen()
   if pressed == 3 :
     window.destroy()

def gamescreen():
  photo = PhotoImage(file="gamescreen.gif")
  canvas.bind("<Button-1>", buttonclick_gamescreen)
  canvas.pack(expand = YES, fill = BOTH)
  canvas.create_image(1, 1, image = photo, anchor = NW)
  game1 = PhotoImage(file="1.gif")
  canvas.create_image(30, 65, image = game1, anchor = NW)
  e1 = Entry(canvas, width = 11)
  e2 = Entry(canvas, width = 11) 
  canvas.create_window(390, 501, window=e1, anchor = NW)
  canvas.create_window(551, 501, window=e2, anchor = NW)
  canvas.after(1, gamescreen)
  window.mainloop()

def cdtimer():
  canvas.delete(ALL)
  global cdtimer
  cdtimer -= 1
  canvas.create_text(510, 6, text=cdtimer, font="Ubuntu 29 bold", anchor = NW) 
  if cdtimer == 0:
    scorescreen()
  else:
    canvas.after(1000, gamescreen)

main()

错误消息：

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python3.2/tkinter/__init__.py", line 1402, in __call__
    return self.func(*args)
  File "/usr/lib/python3.2/tkinter/__init__.py", line 490, in callit
    func(*args)
  File "/home/ppppwn3d/workspace/Python/JailBreakBob/JailBreakBob.py", line 50, in     gamescreen
    e1 = Entry(canvas, width = 11)
  File "/usr/lib/python3.2/tkinter/__init__.py", line 2372, in __init__
    Widget.__init__(self, master, 'entry', cnf, kw)
  File "/usr/lib/python3.2/tkinter/__init__.py", line 1952, in __init__
    cnf = _cnfmerge((cnf, kw))
  File "/usr/lib/python3.2/tkinter/__init__.py", line 71, in _cnfmerge
    if isinstance(cnfs, dict):
RuntimeError: maximum recursion depth exceeded while calling a Python object

Answer 1

你想试试穿线吗？

import thread
import time

def myFunct():
    sec = 60
    n = 1
    for i in range(sec/n):
        updateClock()
        time.sleep(n)
    finalFunct()

thread.start_new_thread(myFunct, ())

只需将sec更改为初始值（以秒为单位），并将n更改为要更新的时间间隔（以秒为单位）。

Answer 2

这是奥克利答案的扩展。它演示了如何在画布中显示时间，以及如何启动整个过程：

from tkinter import *
root = Tk()
canvas = Canvas(root)
canvas.pack()
time = 60
def tick():
    # You have to clear the canvas each time the clock updates 
    # (otherwise it writes on top of the old time).  Since the
    # time is the only thing in the canvas, delete(ALL) works
    # perfectly (if it wasn't however, you can delete the id
    # that goes with the clock).
    canvas.delete(ALL)
    # I have to declare time as a global because I'm not using
    # a class (otherwise, I could do something like self.time -= 1)
    global time
    time -= 1
    # You can place the time wherever in the canvas
    # (I chose 10,10 for the example)
    canvas.create_text(10, 10, text=time)
    if time == 0:
        do_something()
    else:
        canvas.after(1000, tick)
canvas.after(1, tick)
root.mainloop()

脚本从60秒开始倒数（显示剩余的时间），当它到达0时，它调用do_something。

Answer 3

您想使用after方法。逻辑是这样的：

def update_clock(self):
    self.counter -= 1
    if self.counter == 0 :
        do_something()
    else:
        self.after(1000, self.update_clock)

以上将从计数器中减去一。如果计数器为零，它会做一些特殊的事情。否则，它会安排自己在一秒钟内再次运行。