禁用提交按钮，直到在Python Tkinter中填写完所有字段

import tkinter as tk

def validate_fields():
    if entry1.get() and entry2.get() and entry3.get():
        submit_button.config(state=tk.NORMAL)
    else:
        submit_button.config(state=tk.DISABLED)

root = tk.Tk()

label1 = tk.Label(root, text="Field 1:")
label1.pack()
entry1 = tk.Entry(root)
entry1.pack()

label2 = tk.Label(root, text="Field 2:")
label2.pack()
entry2 = tk.Entry(root)
entry2.pack()

label3 = tk.Label(root, text="Field 3:")
label3.pack()
entry3 = tk.Entry(root)
entry3.pack()

submit_button = tk.Button(root, text="Submit", state=tk.DISABLED)
submit_button.pack()

# 绑定输入框内容变化的事件，调用validate_fields函数
entry1.bind("<KeyRelease>", lambda event: validate_fields())
entry2.bind("<KeyRelease>", lambda event: validate_fields())
entry3.bind("<KeyRelease>", lambda event: validate_fields())

root.mainloop()