在阻止代码时在TKinter中显示倒计时计时器，但不要冻结图形用户界面

import tkinter as tk
import threading

class TimerApp:
    def __init__(self, root):
        self.root = root
        self.countdown = 10
        self.label = tk.Label(root, text="")
        self.label.pack()
        self.start_button = tk.Button(root, text="Start", command=self.start_timer)
        self.start_button.pack()

    def start_timer(self):
        self.start_button.config(state=tk.DISABLED)  # 禁用开始按钮
        self.timer_thread = threading.Thread(target=self.update_timer)
        self.timer_thread.start()

    def update_timer(self):
        while self.countdown > 0:
            self.label.config(text=str(self.countdown))
            self.countdown -= 1
            self.root.update()  # 更新图形用户界面
            time.sleep(1)
        self.label.config(text="Time's up!")
        self.start_button.config(state=tk.NORMAL)  # 启用开始按钮

root = tk.Tk()
app = TimerApp(root)
root.mainloop()