Why am I getting an error message saying: " RefNumCur = RefNumEntry.get() AttributeError: 'NoneType' object has no attribute 'get' "?

Question

此代码全部出现在我的增值税计算器程序主菜单屏幕的 class 中。我无法从输入框中检索值。

前几行初始化输入框要使用的文本变量。

    RefNumCur = StringVar()
    AddressCur = StringVar()
    DateCompCur = StringVar()
    DateBankCur = StringVar()
    JobSourceCur = StringVar()
    JobTypeCur = StringVar()
    AmountCur = StringVar()

我在这里创建了一个函数，它在将值保存到数据库之前启动一系列有效性算法。但首先我需要从输入框中获取值。

    def SaveEntry(*args):
        RefNumCur = RefNumEntry.get()
        AddressCur = AddressEntry.get()
        DateCompCur = DateCompEntry.get()
        DateBankCur = DateBankEntry.get()
        JobSourceCur = JobSourceEntry.get()
        JobTypeCur = JobTypeEntry.get()
        AmountCur = AmountEntry.get()

        CheckRefNum(RefNumCur)

这是我制作和放置输入框的地方。

    RefNumEntry = Entry(textvariable = RefNumCur).grid(row = 2,column =3, columnspan = 2)
    AddressEntry = Entry(textvariable = AddressCur).grid(row = 3,column = 3, columnspan = 2)
    DateCompEntry = Entry(textvariable = DateCompCur).grid(row = 4,column =3, columnspan = 2)
    DateBankEntry = Entry(textvariable = DateBankCur).grid(row = 5,column = 3, columnspan = 2)
    JobSourceEntry = Entry(textvariable = JobSourceCur).grid(row = 6, column =3, columnspan = 2)
    JobTypeEntry = Entry(textvariable = JobTypeCur).grid(row = 7, column =3, columnspan = 2)
    AmountEntry = Entry(textvariable = AmountCur).grid(row = 8,column = 3, columnspan = 2)

Answer 1

gridreturnsNone。 （pack、place 相同）

您需要像这样分隔行：

RefNumEntry = Entry(textvariable=RefNumCur).grid(row=2, column=3, columnspan=2)

进入：

RefNumEntry = Entry(textvariable=RefNumCur)
RefNumEntry.grid(row=2, column=3, columnspan=2)

否则，RefNumEntry 将引用 None 而不是 Entry 对象。