Python 在关闭Tkinter小部件时完全停止进程并退出

您不应该在您的图形用户界面中使用阻塞无限循环，而是使用self.after来调度稍后要调用的函数，现在您不需要调用update来重画图形用户界面，并且当图形用户界面退出时不再调用该函数.

import tkinter as tk
import time

class app(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("An app")
        self.create_widgets()
        self.after(1000, lambda: self.a_process(0))

    def create_widgets(self):
        self.text = tk.Label(self, text = "Hello World!")
        self.text.pack()
        self.cancelButton = tk.Button(self, text = "Cancel", command = self.destroy)
        self.cancelButton.pack()

    def a_process(self, i):
        self.text.config(text = f"Message # {i}")
        if i+1 < 100:  # call this function later with different args
            self.after(1000,lambda: self.a_process(i+1))

    def destroy(self):
        super().destroy()

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

或者，如果您有一个很长的任务想要在后台运行，您可以将它调度在一个threading.Thread守护进程上(将在python退出时终止)，并让它在更新图形用户界面的函数上调用self.after.

因为在主循环结束时不会发生用after调用的函数，所以当图形用户界面退出时，您不会try 更新图形用户界面.

import tkinter as tk
import time
import threading

class app(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title("An app")
        self.create_widgets()
        self.counter = 0
        thread = threading.Thread(target = self.a_process, args=[], daemon=True)
        thread.start()
        
    def create_widgets(self):
        self.text = tk.Label(self, text = "Hello World!")
        self.text.pack()
        self.cancelButton = tk.Button(self, text = "Cancel", command = self.destroy)
        self.cancelButton.pack()

    def a_process(self):
        for i in range(100):
            self.counter += 1
            self.after(0,self.update_counter)
            time.sleep(1)
            
    def update_counter(self):
        self.text.config(text = f"Message # {self.counter}")

    def destroy(self):
        super().destroy()

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