在下拉框值被更改时手动调用update方法来刷新控件。

示例代码：

from tkinter import * from tkinter.ttk import *

root = Tk()

创建两个级联的下拉框

top_var = StringVar() top_combo = Combobox(root, textvariable=top_var) top_combo.pack()

sub_var = StringVar() sub_combo = Combobox(root, textvariable=sub_var) sub_combo.pack()

添加下拉框值

top_combo['values'] = ['Fruits', 'Vegetables'] top_combo.current(0)

fruits = ['Apple', 'Banana', 'Cherry'] vegetables = ['Broccoli', 'Carrot', 'Lettuce']

top_value = top_var.get()

更新子下拉框值的函数

def update_sub(): if top_value == 'Fruits': sub_combo['values'] = fruits elif top_value == 'Vegetables': sub_combo['values'] = vegetables

更新下拉框值

update_sub()

当父下拉框更改值时，更新子下拉框的值

def on_select(event): global top_value top_value = top_var.get() update_sub()

top_combo.bind('<<ComboboxSelected>>', on_select)

root.mainloop()