使用tkinter时链接的类属性

import tkinter as tk

class App:
    def __init__(self, root):
        self.root = root
        self.label_var = tk.StringVar()
        self.entry_var = tk.StringVar()

        self.label = tk.Label(root, textvariable=self.label_var)
        self.entry = tk.Entry(root, textvariable=self.entry_var)
        self.button = tk.Button(root, text="Update", command=self.update_label)

        self.label.pack()
        self.entry.pack()
        self.button.pack()

    def update_label(self):
        self.label_var.set(self.entry_var.get())

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