import tkinter
from tkinter import ttk
 
def go(*args):  #处理事件，*args表示可变参数
  print(comboxlist.get()) #打印选中的值
 
win=tkinter.Tk() #构造窗体
comvalue=tkinter.StringVar()#窗体自带的文本，新建一个值
comboxlist=ttk.Combobox(win,textvariable=comvalue) #初始化
comboxlist["values"]=("1","2","3","4")
comboxlist.current(0) #选择第一个
comboxlist.bind("<<ComboboxSelected",go) #绑定事件,(下拉列表框被选中时，绑定go()函数)
comboxlist.pack()
 
win.mainloop() #进入消息循环

from tkinter import *
from tkinter import ttk
 
#Create an instance
win = Tk()
win.title("Learn Combobox")
 
#create a Label
lb1 = Label(win, text = "Below is a combobox 1", font = "tahoma 12 normal")
lb1.grid(column = 0, row = 0, padx = 8, pady = 4)
 
def show_select_1():
	print("post_command: show_select")
	print(value.get())
 
#Define tkinter data type
data = ["a","b","c"]
value = StringVar()
 
#Create a combobox, and tighter it to value
cbx_1 = ttk.Combobox(win, width = 12, height = 8, textvariable = value, postcommand = show_select_1)
cbx_1.grid(column = 0, row = 1)
 
#add data to combobox
cbx_1["values"] = data
 
#======================================================================================================
#create a Label
lb2 = Label(win, text = "Below is a combobox 2", font = "tahoma 12 normal")
lb2.grid(column = 0, row = 4, padx = 8, pady = 4)
 
def show_data_2(*args):
	print("Event: ComboboxSelected")
	print(cbx_2.get())
 
#Define tkinter data type
data2 = ["a2","b2","c2","d2","e2"]
 
#Create a combobox, and tighter it to value
cbx_2 = ttk.Combobox(win, width = 12, height = 8)
cbx_2.grid(column = 0, row = 5)
 
#set cbx_2 as readonly
cbx_2.configure(state = "readonly")
 
#add data to combobox
cbx_2["values"] = data2
#set the initial data [index =2] to shows up when win generated
cbx_2.current(2)
 
#bind a event
cbx_2.bind("<<ComboboxSelected", show_data_2)
 
win.mainloop()