python - 根据组合框 1 填充组合框 2

Question

我有 2 个组合框。但我需要根据combo_maker的值更新combo_type。

我尝试制作 ComboSelected 但失败了。

当combobox_maker我选择了任何值。 combobox_type 没有变化。我尝试了一些代码更改，但没有任何结果。

from tkinter import *
from tkinter import ttk
import sqlite3
import tkinter as tk
from tkinter import messagebox
import configparser
import tkinter
import tkinter
import mysql.connector
from mysql.connector import Error

Product = Tk()
Product.title ('App - Add Product')
Product.geometry("800x600")
#CONNECT DB
def connect_db():
        config = configparser.ConfigParser()
        config.read('config.ini')
        return mysql.connector.connect(host = config['mysql']['host'],
                                        port = config['mysql']['port'],
                                        user = config['mysql']['database_user'],
                                        passwd = config['mysql']['database_password'],
                                        db = config['mysql']['database_name'])
#CONNECT DB

#COMBO MAKER
def combo_input_maker():#<--Populate combo_maker
    conn = connect_db()
    cursor = conn.cursor()
    cursor.execute("SELECT maker_name FROM makers")
    result=cursor.fetchall()
    return result
#COMBO MAKER

#COMBO TYPE
def combo_input_type():#<--Populate combo_type
    conn = connect_db()
    cursor = conn.cursor()
    some_name = combo_maker.get()#<--Query with value select from combo_maker
    cursor.execute("SELECT t1.type FROM maker_types t1 INNER JOIN makers t2 ON t1.maker_id = t2.id WHERE maker_name =%s", [some_name])
    result=cursor.fetchall()
    return result
#COMBO TYPE

combo_maker = ttk.Combobox(Product,state="readonly")
combo_maker['value'] = [item for result in combo_input_maker() for item in result if item]
combo_maker.current(0)
combo_maker.bind('<<ComboboxSelected>>', combo_input_type())#<--When ComboboxSelected in combo_maker, call def combo_input_type()
combo_maker.place(x=5, y=5, height = 25, width = 180)

combo_type = ttk.Combobox(Product,state="readonly")
combo_type['value'] = [item for result in combo_input_type() for item in result if item]
combo_type.current(0)
combo_type.place(x=200, y=5, height = 25, width = 180)

Product.mainloop()

当combo_maker改变时，combo_type没有改变。

Answer 1

主要问题是:

1. 您错误地初始化了combo_maker；
2. 您通过了以下结果 comb_input_type() 而不是函数引用 combo_make.bind(...) 中的 comb_input_type。

以下是根据您的修改后的代码:

#COMBO MAKER
def combo_input_maker():#<--Populate combo_maker
    # use global cursor instead of local one
    cursor.execute("SELECT maker_name FROM makers")
    result=[rec[0] for rec in cursor]
    return result
#COMBO MAKER

#COMBO TYPE
def combo_input_type(event=None):#<--Populate combo_type
    some_name = combo_maker.get()#<--Query with value select from combo_maker
    # use global cursor
    cursor.execute("SELECT t1.type FROM maker_types t1 INNER JOIN makers t2 ON t1.maker_id = t2.id WHERE maker_name = %s", [some_name])
    result = [rec[0] for rec in cursor]
    # populate combo_type
    combo_type['value'] = result
    combo_type.current(0)
    return result
#COMBO TYPE

# connect DB once
conn = connect_db()
cursor = conn.cursor()

combo_maker = ttk.Combobox(Product,state="readonly")
combo_maker['value'] = combo_input_maker() #[item for result in combo_input_maker() for item in result if item]
combo_maker.bind('<<ComboboxSelected>>', combo_input_type) # use function reference here
combo_maker.place(x=5, y=5, height = 25, width = 180)

combo_type = ttk.Combobox(Product,state="readonly")
combo_type.place(x=200, y=5, height = 25, width = 180)