tkinter无效的命令名称

Question

I get an error similar to: invalid command name ".91418712.91418792" when I click the Quit button in my program. I have googled this but an unsure how to fix the issue.

The issue apparently is that my thread is trying to update GUI elements that no longer exists which is why I put a sleep in before doing the destroy. The following is closely related to my issue _tkinter.TclError: invalid command name ".4302957584"

A condensed version of the code:

#!/usr/bin/python
import Adafruit_GPIO as GPIO
import Adafruit_GPIO.FT232H as FT232H
from time import sleep
from threading import Thread
import Tkinter as tk
import tkFont

# Temporarily disable the built-in FTDI serial driver on Mac & Linux platforms.
FT232H.use_FT232H()

# Create an FT232H object that grabs the first available FT232H device found.
device = FT232H.FT232H()

d0 = 0
d1 = 1

device.setup(d0, GPIO.IN)
device.setup(d1, GPIO.IN)

class Application():
    def __init__(self):
        self.root = tk.Tk()
        self.root.title("Show Voltage")
        self.root.grid()
        self.createWidgets()
        self.stop = False
        self.watcher = Thread(target = self.watcher, name="watcher")
        self.watcher.start()
        self.root.mainloop()

    def changeBackground(self, cell):
        if cell == 0:
            self.la_d0.config(bg="green")
        elif cell == 1:
            self.la_d1.config(bg="green")

    def returnBackground(self, cell):
        if cell == 0:
            self.la_d0.config(bg="black")
        elif cell == 1:
            self.la_d1.config(bg="black")

    def quit(self):
        self.stop = True
        self.watcher.join()
        sleep(0.3)
        self.root.destroy()

    def watcher(self):
        while not self.stop:
            self.wa_d0 = device.input(d0)
            self.wa_d1 = device.input(d1)

            if self.wa_d0 == GPIO.HIGH:
                self.changeBackground(0)
            else:
                self.returnBackground(0)

            if self.wa_d1 == GPIO.HIGH:
                self.changeBackground(1)
            else:
                self.returnBackground(1)
            sleep(0.0125)

    def createWidgets(self):
        self.font = tkFont.Font(family='Helvetica', size=50, weight='bold')
        self.bt_font = tkFont.Font(family='Helvetica', size=18, weight='bold')

        self.fr_d0 = tk.Frame(height=100, width=100)
        self.la_d0 = tk.Label(self.fr_d0, text="d0", bg="black", fg="red", font=self.font)
        self.fr_d1 = tk.Frame(height=100, width=100)
        self.la_d1 = tk.Label(self.fr_d1, text="d1", bg="black", fg="red", font=self.font)
        self.fr_quit = tk.Frame(height=40, width=200)
        self.bt_quit = tk.Button(self.fr_quit, text="Quit!", bg="white", command=self.quit, font=self.bt_font)

        self.fr_d0.grid(row=0, column=0)
        self.fr_d0.pack_propagate(False)
        self.la_d0.pack(fill="both", expand=1)
        self.fr_d1.grid(row=0, column=2)
        self.fr_d1.pack_propagate(False)
        self.la_d1.pack(fill="both", expand=1)
        self.fr_quit.grid(row=1, column=0, columnspan=3)
        self.fr_quit.pack_propagate(False)
        self.bt_quit.pack(fill="both", expand=1)

app = Application()

Answer 1

not sure exactly what fixed it but this no longer creates the error

#!/usr/bin/python
import Adafruit_GPIO as GPIO
import Adafruit_GPIO.FT232H as FT232H
from time import sleep
from threading import Thread
import Tkinter as tk
import tkFont

# Temporarily disable the built-in FTDI serial driver on Mac & Linux platforms.
FT232H.use_FT232H()

# Create an FT232H object that grabs the first available FT232H device found.
device = FT232H.FT232H()

d0 = 0
d1 = 1

device.setup(d0, GPIO.IN)
device.setup(d1, GPIO.IN)

class Application():
    def __init__(self):
        self.root = tk.Tk()
        self.root.title("Show Voltage")
        self.root.grid()
        self.createWidgets()
        self.stop = False
        self.watcherThread = Thread(target = self.watcher, name="watcher")
        self.watcherThread.start()
        self.root.mainloop()

    def changeBackground(self, cell):
        if cell == 0:
            self.la_d0.config(bg="green")
        elif cell == 1:
            self.la_d1.config(bg="green")

    def returnBackground(self, cell):
        if cell == 0:
            self.la_d0.config(bg="black")
        elif cell == 1:
            self.la_d1.config(bg="black")

    def destroy(self):
        self.root.destroy()

    def quit(self):
        self.stop = True
        self.watcherThread.join()
        self.root.after(300, self.destroy)

    def watcher(self):
        while not self.stop:
            self.wa_d0 = device.input(d0)
            self.wa_d1 = device.input(d1)

            if self.wa_d0 == GPIO.HIGH:
                self.changeBackground(0)
            else:
                self.returnBackground(0)

            if self.wa_d1 == GPIO.HIGH:
                self.changeBackground(1)
            else:
                self.returnBackground(1)
            sleep(0.0125)

    def createWidgets(self):
        self.font = tkFont.Font(family='Helvetica', size=50, weight='bold')
        self.bt_font = tkFont.Font(family='Helvetica', size=18, weight='bold')

        self.fr_d0 = tk.Frame(height=100, width=100)
        self.la_d0 = tk.Label(self.fr_d0, text="d0", bg="black", fg="red", font=self.font)
        self.fr_d1 = tk.Frame(height=100, width=100)
        self.la_d1 = tk.Label(self.fr_d1, text="d1", bg="black", fg="red", font=self.font)
        self.fr_quit = tk.Frame(height=40, width=200)
        self.bt_quit = tk.Button(self.fr_quit, text="Quit!", bg="white", command=self.quit, font=self.bt_font)

        self.fr_d0.grid(row=0, column=0)
        self.fr_d0.pack_propagate(False)
        self.la_d0.pack(fill="both", expand=1)
        self.fr_d1.grid(row=0, column=2)
        self.fr_d1.pack_propagate(False)
        self.la_d1.pack(fill="both", expand=1)
        self.fr_quit.grid(row=1, column=0, columnspan=3)
        self.fr_quit.pack_propagate(False)
        self.bt_quit.pack(fill="both", expand=1)

app = Application()

thank you all for all the input!! :)