Python 未获取条目小部件的tkinter值

这是我的输入小部件和按钮单击的代码

# Amount entry here
    textBoxAmount = Entry(win, textvariable=amount_entry)
    textBoxAmount.grid(row=2, column=1)

    # Deposit button here
    buttonDeposit = tk.Button(text="Deposit", command=perform_deposit())
    buttonDeposit.grid(row=2, column=2)

&我的职能是执行存款

def perform_deposit():
    '''Function to add a deposit for the amount in the amount entry to the
       account's transaction list.'''
    global account
    global amount_entry
    global balance_label
    global balance_var

    # Try to increase the account balance and append the deposit to the account file
    #input = amount_text.get("1.0",END)
    amount_entered = amount_entry.get()
    print("amount entered : {}".format(amount_entry.get()))
    print(amount_entered)
    #balance_var= account.deposit(amount_entry.get())
    print(balance_var)

输出就像

amount entered : 

---

在文本小部件中放入200时未获得textvariable值这段代码没有运行，所以我猜它应该是什么样子

在使用之前，您需要创建

StringVar（）

amount\u条目。您可以在函数

perform_deposit（）

之外执行此操作，而不必将其声明为

全局

将按钮与命令关联时，不应包含括号，因为在声明按钮命令时，括号将运行函数

检查以下示例：

from tkinter import *

win = Tk()
win.geometry('300x200')

amount_entry = StringVar()

def perform_deposit():
    global balance_var
    amount_entered = amount_entry.get()
    print("amount entered : {}".format(amount_entry.get()))

# Amount entry here
textBoxAmount = Entry(win, textvariable=amount_entry)
textBoxAmount.grid(row=2, column=1)

# Deposit button here
buttonDeposit = Button(text="Deposit", command=perform_deposit)
buttonDeposit.grid(row=2, column=2)

win.mainloop()