如何在tkinter中的窗口类之间传递信息？

import tkinter as tk

class Window1(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.title("Window 1")
        self.button = tk.Button(self, text="Open Window 2", command=self.open_window2)
        self.button.pack()

    def open_window2(self):
        global shared_data
        shared_data = "Hello from Window 1"
        self.destroy()
        window2 = Window2()
        window2.mainloop()

class Window2(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.title("Window 2")
        label = tk.Label(self, text=shared_data)
        label.pack()

shared_data = ""

window1 = Window1()
window1.mainloop()

import tkinter as tk

class Window1(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.title("Window 1")
        self.button = tk.Button(self, text="Open Window 2", command=self.open_window2)
        self.button.pack()

    def open_window2(self):
        self.destroy()
        window2 = Window2(self.update_label)
        window2.mainloop()

    def update_label(self, data):
        self.label.config(text=data)

class Window2(tk.Tk):
    def __init__(self, callback):
        tk.Tk.__init__(self)
        self.title("Window 2")
        self.callback = callback
        self.entry = tk.Entry(self)
        self.entry.pack()
        self.button = tk.Button(self, text="Send Data", command=self.send_data)
        self.button.pack()

    def send_data(self):
        data = self.entry.get()
        self.callback(data)
        self.destroy()

window1 = Window1()
window1.mainloop()

import tkinter as tk

class SharedData:
    def __init__(self):
        self.data = ""

class Window1(tk.Tk):
    def __init__(self, shared_data):
        tk.Tk.__init__(self)
        self.title("Window 1")
        self.shared_data = shared_data
        self.button = tk.Button(self, text="Open Window 2", command=self.open_window2)
        self.button.pack()

    def open_window2(self):
        self.destroy()
        window2 = Window2(self.shared_data)
        window2.mainloop()

class Window2(tk.Tk):
    def __init__(self, shared_data):
        tk.Tk.__init__(self)
        self.title("Window 2")
        self.shared_data = shared_data
        self.entry = tk.Entry(self)
        self.entry.pack()
        self.button = tk.Button(self, text="Send Data", command=self.send_data)
        self.button.pack()

    def send_data(self):
        data = self.entry.get()
        self.shared_data.data = data
        self.destroy()

shared_data = SharedData()

window1 = Window1(shared_data)
window1.mainloop()