什么导致 Tkinter 回调异常？

编程问答 2022-07-14

问题描述

我正在尝试编写一个可以添加无限房间的程序，因此我的所有代码都是围绕使用一个变量来推断哪个房间是哪个房间而构建的。然而，当我运行它时，它给了我一个错误，它没有直接引用我的代码中的任何一行，而且由于我是一个相当新的程序员，我不知道这意味着什么。此外，我的代码到处都是，而且不完整。感谢您的帮助！

错误

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\SCA0023\AppData\Local\Programs\Python\python38\lib\tkinter\__init__.py",line 1892,in __call__
    return self.func(*args)
TypeError: 'nonetype' object is not callable

代码

from tkinter import *

root = Tk()


class Room:
    def __init__(self,items):
        self.objects = []
        self.objects.append(items)

    def list(self):
        print(self.objects)


def addkitchenmenu(r): #add a new option menu attributed to a new room
    globals()[f'kitchenvar_{r}'] = StringVar(root)
    globals()[f'kitchenvar_{r}'].set("Add an appliance")
    globals()[f'kitchenvar_{r}'].trace('w',applianceadd(r))
    kitchenitems = ['Kettle','Toaster']
    globals()[f'appliancelist_{r}'] = OptionMenu(root,globals()[f'kitchenvar_{r}'],*kitchenitems).pack()
    addkitchen(r)


def applianceadd(r): #add a new room
    globals()[f'kobjects_{r}'] = []
    globals()[f'kobjects_{r}'].append(globals()[f'kitchenvar_{r}'].get())
    items = globals()[f'kobjects_{r}']
    globals()[f'kroom_{r}'] = Room(items)
    globals()[f'kroom_{r}'].list()


def addkitchen(r): #add an appliance
    globals()[f'addappliace{r}'] = Button(root,text='add appliance',command=lambda: applianceadd(r))


def newkitchencheck(): #find the next name for a room that isn't taken
    varnotfound = True
    a = 0

    while varnotfound:
        if f'kroom{a}' in globals():
            a += 1
        else:
            r = a
            varnotfound = False
            addkitchenmenu(r)


addroombutton = Button(root,text="add kitchen",command=newkitchencheck)
addroombutton.pack()

root.mainloop()

解决方法

您正在将 Applianceadd(r) 的结果（无）传递给 .trace()。更改为 .trace("w",lambda *_: Applianceaddr(r)).

callable-objectpythontkinter