tkinter 倒计时应用程序停止和重置按钮不起作用

Question

我在 tkinter 倒计时应用程序上写了第一次尝试，我正在努力解决停止和重置按钮以及界面设计的部分问题。

我的停止按钮什么也不做，而我的重置按钮会重置值，但会立即继续倒计时。 我怀疑这是因为我在 init 方法中将self.running设置为True并且我的应用程序一次又一次地循环遍历这些行。 我如何防止这种情况发生？

另一个问题是我所有输入字段中的宽度参数似乎都被忽略了。 如何为所有三个字段分配相同的宽度？

谢谢你的帮助。

from tkinter import *
import time
from tkinter import messagebox

class Application(Frame):
    def __init__(self,master):
        super(Application,self).__init__(master)
        self.place()
        self.widgets()
        self.running = True

    def widgets(self):

        self.hour = StringVar()
        self.hour.set("00")
        # Why is the width ignored?
        self.hour_entry = Entry(width = 7, font=("Calibri",14,""), textvariable = self.hour)
        self.hour_entry.place(x = 10, y = 10)

        self.minute = StringVar()
        self.minute.set("00")
        self.minute_entry = Entry(width = 7, font=("Calibri",14,""), textvariable = self.minute)
        self.minute_entry.place(x = 30, y = 10)

        self.second = StringVar()
        self.second.set("00")
        self.seconds_entry = Entry(width = 7, font=("Calibri",14,""), textvariable = self.second)
        self.seconds_entry.place(x = 50, y = 10)

        self.start_btn = Button(text = "Start", command=self.clock)
        self.start_btn.place(x = 30, y = 100)

        self.stop_btn = Button(text = "Stop", command=self.stop)
        self.stop_btn.place(x = 70, y = 100)

        self.reset_btn = Button(text = "Reset", command=self.reset)
        self.reset_btn.place(x = 110, y = 100)

    def clock(self):

        if self.running == True:

            self.time_total = int(self.hour_entry.get())*3600 + int(self.minute_entry.get())*60 + int(self.seconds_entry.get())

            while self.time_total > -1:

                # returns 3600/60 = 60 with 0 left: so that's 60 min, 0 seconds
                self.mins, self.secs = divmod(self.time_total,60) 

                self.hours = 0
                if self.mins > 60:
                    
                    self.hours, self.mins = divmod(self.mins, 60)

                self.hour.set("{0:02d}".format(self.hours))
                self.minute.set("{0:02d}".format(self.mins))
                self.second.set("{0:02d}".format(self.secs))

                self.time_total -= 1
                root.update()
                time.sleep(1)

                if self.time_total == 0:
                    messagebox.showinfo("Time Countdown", "Time's up!")
    
    def start(self):
        self.running = True
        self.clock()

    def stop(self):
        self.running = False

    def reset(self):
        self.running = False
        self.hour.set("00")
        self.minute.set("00")
        self.second.set("00")
    
if __name__ == '__main__':
    root = Tk()
    app = Application(root)
    mainloop()

Answer 1

对于计时器，使用after方法而不是sleep 。

正在使用条目宽度，但place方法将一个条目放在另一个条目的顶部。

此外 - 从按钮单击调用start方法以重置running标志。

试试这个代码：

from tkinter import *
import time
from tkinter import messagebox

class Application(Frame):
    def __init__(self,master):
        super(Application,self).__init__(master)
        self.place()
        self.widgets()
        self.running = False

    def widgets(self):
        self.hour = StringVar()
        self.hour.set("00")
        # Why is the width ignored?
        self.hour_entry = Entry(width = 4, font=("Calibri",14,""), textvariable = self.hour)
        self.hour_entry.place(x = 10, y = 10)

        self.minute = StringVar()
        self.minute.set("00")
        self.minute_entry = Entry(width = 4, font=("Calibri",14,""), textvariable = self.minute)
        self.minute_entry.place(x = 60, y = 10)

        self.second = StringVar()
        self.second.set("00")
        self.seconds_entry = Entry(width = 4, font=("Calibri",14,""), textvariable = self.second)
        self.seconds_entry.place(x = 110, y = 10)

        self.start_btn = Button(text = "Start", command=self.start)
        self.start_btn.place(x = 30, y = 100)

        self.stop_btn = Button(text = "Stop", command=self.stop)
        self.stop_btn.place(x = 70, y = 100)

        self.reset_btn = Button(text = "Reset", command=self.reset)
        self.reset_btn.place(x = 110, y = 100)

    def clock(self):
        if self.running == True:
            
            # returns 3600/60 = 60 with 0 left: so that's 60 min, 0 seconds
            self.mins, self.secs = divmod(self.time_total,60) 

            self.hours = 0
            if self.mins > 60:
                self.hours, self.mins = divmod(self.mins, 60)

            self.hour.set("{0:02d}".format(self.hours))
            self.minute.set("{0:02d}".format(self.mins))
            self.second.set("{0:02d}".format(self.secs))

            root.update()
            #time.sleep(1)
            root.after(1000, self.clock)  # wait 1 second, re-call clock

            if self.time_total == 0:
                self.running = False
                messagebox.showinfo("Time Countdown", "Time's up!")
            self.time_total -= 1
                    
    
    def start(self):
        self.time_total = int(self.hour_entry.get())*3600 + int(self.minute_entry.get())*60 + int(self.seconds_entry.get())
        self.running = True
        self.clock()

    def stop(self):
        self.running = False

    def reset(self):
        self.running = False
        self.hour.set("00")
        self.minute.set("00")
        self.second.set("00")
    
if __name__ == '__main__':
    root = Tk()
    app = Application(root)
    mainloop()