tkinter 运行多线程任务

from tkinter import ttk, Tk, StringVar
import time
import threading

class Window(Tk):
    def __init__(self, **kw):
        super().__init__(**kw)
        self.download_thread = None
        self.download_button = ttk.Button(self, text="开始下载", command=self.start_download_thread)
        self.result_label = ttk.Label(self, text="")
        self.text_var = StringVar(self)
        self.entry = ttk.Entry(self, textvariable=self.text_var)
        self.label = ttk.Label(self, textvariable=self.text_var)
        self.text_var.trace_add("write", self.update_text())
        self.download_button.grid(row=0, column=0)
        self.result_label.grid(row=1, column=0)
        self.entry.grid(row=0, column=1)
        self.label.grid(row=1, column=1)
        
    def start_download_thread(self):
        if self.download_thread is None or not self.download_thread.is_alive():
            self.download_thread = threading.Thread(target=self.download, daemon=True)
            self.download_thread.start()

    def download(self):
        # 模拟下载任务，这里可以替换为实际的下载操作
        for i in range(1, 6):
            self.result_label.config(text=f"下载中... ({i}/5)")
            self.update()  # 更新主界面以显示下载进度
            time.sleep(2)  # 模拟下载延迟
        self.result_label.config(text="下载完成")

    def update_text(self, *args):
        def wrap(*args):
            self.text_var.set(self.entry.get())
        return wrap

root = Window()
root.title("多线程示例")
root.mainloop()