python - 在 while 语句内暂停倒计时器

Question

我有一个循环，当通过单击按钮更改变量时启动和暂停，并且停止按钮完全停止循环。我可以使用分配的按钮开始/暂停和停止循环。在该循环中，我需要一个倒计时器。当主循环暂停时，倒计时器还需要暂停，跟上原来的位置，并在主循环取消暂停时重新启动，但一切都卡住，直到倒计时器完成。

class MYmain(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        self.title_font = tkfont.Font(family='Helvetica', size=18,     weight="bold", slant="italic")
        self.geometry("800x600+0+0")
        container = tk.Frame(self)
        container.pack(side="top", fill="both", expand=True)
        container.grid_rowconfigure(0, weight=1)
        container.grid_columnconfigure(0, weight=1)

        self.frames = {}
        self.frames["mainframe"] = mainframe(parent=container,     controller=self)
        self.frames["mainframe"].grid(row=0, column=0, sticky="nsew")
        self.show_frame("mainframe")


    def show_frame(self, page_name):
        '''Show a frame for the given page name'''
        frame = self.frames[page_name]
        frame.place(x=0, y=368, width=800, height=232)
        frame.tkraise()


    def shutdown(self):
        self.destroy()


    def get_page(self, page_class):
        return self.frames[page_class]


if __name__ == "__main__":
    app = MYmain()
    app.mainloop()

#I also have my main form
import tkinter as tk  # python 3
import sys
import time


class mainframe(tk.Frame):

    def __init__(self, parent, controller):
        tk.Frame.__init__(self, parent)
        self.controller = controller
        self.running = False
        self.aboutToQuit = False
        self.someVar = 0

        label = tk.Label(self, text="Handheld page", font=controller.title_font)
        label.pack(side="top", fill="x", pady=10)

        font18 = "-family {Segoe UI} -size 18"
        frame_top_left = tk.Frame(self)
        frame_top_left.place(relx=0.0, rely=0.0, relheight=0.363, relwidth=0.456)
        frame_top_left.configure(relief='groove')
        frame_top_left.configure(borderwidth="2")
        frame_top_left.configure(relief='groove')
        frame_top_left.configure(background="#3f53d8")
        frame_top_left.configure(width=365)

        frame_cmd = tk.Frame(self)
        frame_cmd.place(relx=0.456, rely=0.0, relheight=0.363, relwidth=0.544)
        frame_cmd.configure(relief='groove')
        frame_cmd.configure(borderwidth="2")
        frame_cmd.configure(relief='groove')
        frame_cmd.configure(background="#31d80f")
        frame_cmd.configure(width=445)

        frame_score = tk.Frame(self)
        frame_score.place(relx=0.0, rely=0.242, relheight=0.138, relwidth=1.0)
        frame_score.configure(relief='groove')
        frame_score.configure(borderwidth="2")
        frame_score.configure(relief='groove')
        frame_score.configure(background="#d81838")
        frame_score.configure(width=800)

        frame_bat = tk.Frame(self)
        frame_bat.place(relx=0.0, rely=0.379, relheight=0.495, relwidth=0.256)
        frame_bat.configure(relief='groove')
        frame_bat.configure(borderwidth="2")
        frame_bat.configure(relief='groove')
        frame_bat.configure(background="#3f53d8")
        frame_bat.configure(width=125)

        frame5 = tk.Frame(self)
        frame5.place(relx=0.256, rely=0.38, relheight=0.495, relwidth=0.744)
        frame5.configure(relief='groove')
        frame5.configure(borderwidth="2")
        frame5.configure(background="#ffffff")
        frame5.configure(width=125)

        button1 = tk.Button(frame5)
        button1.place(relx=0.444, rely=0.296, height=42, width=98)
        button1.configure(activebackground="#ececec")
        button1.configure(activeforeground="#000000")
        button1.configure(background="#d9d9d9")
        button1.configure(disabledforeground="#a3a3a3")
        button1.configure(foreground="#000000")
        button1.configure(highlightbackground="#d9d9d9")
        button1.configure(highlightcolor="black")
        button1.configure(pady="0")
        button1.configure(text='''Quit''')
        button1.configure(width=98)
        button1.configure(command=self.quitme)

        buttont1 = tk.Button(frame5, text="stop comm loop",
                         command=self.toggledoquit)
        buttont1.place(relx=0.444, rely=0.496, height=42, width=90)

        buttontt1 = tk.Button(frame5, text="set pause (attr)",
                         command=self.togglesetattr)
        buttontt1.place(relx=0.244, rely=0.496, height=42, width=90)


        frame6 = tk.Frame(self)
        frame6.place(relx=0.0, rely=0.867, relheight=0.142, relwidth=1.0)
        frame6.configure(relief='groove')
        frame6.configure(borderwidth="2")
        frame6.configure(relief='groove')
        frame6.configure(background="#ced83c")
        frame6.configure(width=125)

        self._attr = False
        self._doquit = False


def doloop(self):
    #print(self.aboutToQuit)
    while not self.aboutToQuit:

        self.controller.update() # always process new events

        if self.running:
            # do stuff
            print(str(self.someVar) + " Send")
## THE ISSUE IS HERE
##          t=15
##          while t > 0:
##                if self.running:
##                    print(t)
##                    t -= 1
##                    time.sleep(.1)
##                else:
##                    time.sleep(.1)

            time.sleep(1)
            self.someVar += 1

        else: # If paused, don't do anything
            time.sleep(.1)

def quitme(self):
    self.toggledoquit()
    self.controller.shutdown()

def togglesetattr(self):
    if self._attr == False:
        self.attr=True
    else:
        self.attr=False

def toggledoquit(self):
    self.doquit = True


@property
def attr(self):
    return self._attr

@attr.setter
def attr(self, value):
    self._attr = self.attr
    self.running = not (self.running)
    if value == True:
        self.doloop()
    else:
        return

@property
def doquit(self):
    return self._doquit

@doquit.setter
def doquit(self, value):
    self.running = False
    self.aboutToQuit = not (self.aboutToQuit)
    self.someVar=0


def stopme(self):
    if self._attr==True:
        self.togglesetattr
    self.aboutToQuit = not (self.aboutToQuit)
    self.someVar=0

如果我注释掉上面的代码，它可以正常工作，但是一旦我取消注释并重新添加倒计时代码，它就会卡住，直到倒计时完成，然后我才能卡住或停止主循环。当主循环停止时，它也需要完全停止。计时器最终将作为标签文本放置。

我添加:

if self.someVar == 5:
    self.toggledoquit()
    print(str(self.someVar) + " Send")
    self.time_var.set(15)
    self.countdown()

到##issue is here区域，然后添加def:

def countdown(self):
temp = int(self.time_var.get())
temp -= 1
self.time_var.set(temp)
if ((temp >= 0) and (self.running==True)):
    print(self.time_var.get())
    self.after(1000, self.countdown)

我的全局标志是 self.running (适用于 doloop)

Answer 1

您的问题是您正在使用time.sleep()。 Tkinter 在循环内运行，因此调用 sleep 等函数会卡住循环。要解决这个问题，请使用 tkinters after 函数。这是一个基本的倒计时器。

import tkinter as tk

root = tk.Tk()
time_var = tk.StringVar(root, value=10)

flag = False
def countdown():
   global flag
   temp = int(time_var.get())
   temp -= 1
   time_var.set(temp)
   if temp >= 0 and not flag:
      root.after(1000, countdown)  # This is where the function is called again. Time is in miliseconds

def stop_timer():
    global flag
    flag = True

def start_timer():
    global flag
    flag = False
    countdown()

tk.Button(root, text='start', command=start_timer).pack(side='bottom')
tk.Button(root, text='pause', command=stop_timer).pack(side='bottom')

time = tk.Label(root, textvariable=time_var)
time.pack()
root.mainloop()

现在您可以对此进行很大改进。但它给出了如何使用 tkinter 同时管理事物的基本概念。