tkinter，如何获取 Entry 小部件的值？

Question

如果利润率具有特定值 (0.23)，我正在尝试为用户提供计算其预计销售利润的可能性。用户应该能够输入任何值作为预计销售额：

from tkinter import *

root = Tk()

margin = 0.23
projectedSales = #value of entry
profit = margin * int(projectedSales)

#My function that is linked to the event of my button
def profit_calculator(event):
    print(profit)


#the structure of the window
label_pan = Label(root, text="Projected annual sales:")
label_profit = Label(root, text="Projected profit")
label_result = Label(root, text=(profit), fg="red")

entry = Entry(root)

button_calc = Button(root, text= "Calculate", command=profit_calculator)
button_calc.bind("<Button-1>", profit_calculator)

#position of the elements on the window
label_pan.grid(row=0)
entry.grid(row=0, column=1)
button_calc.grid(row=1)              
label_profit.grid(row=2)
label_result.grid(row=2, column=1)

root.mainloop()

Answer 1

您可以使用以下get方法获取 Entry 小部件内部的内容：

entry = tkinter.Entry(root)
entryString = entry.get()

这是一个可以满足您的要求的示例：

import tkinter as tk

root = tk.Tk()

margin = 0.23

entry = tk.Entry(root)

entry.pack()

def profit_calculator():
    profit = margin * int(entry.get())
    print(profit)

button_calc = tk.Button(root, text="Calculate", command=profit_calculator)
button_calc.pack()

root.mainloop()

您可能还想使用textvariableoption 和tkinter.IntVar()class 来同步多个小部件的整数文本，例如：

import tkinter as tk

root = tk.Tk()

margin = 0.23
projectedSales = tk.IntVar()
profit = tk.IntVar()

entry = tk.Entry(root, textvariable=projectedSales)

entry.pack()

def profit_calculator():
    profit.set(margin * projectedSales.get())

labelProSales = tk.Label(root, textvariable=projectedSales)
labelProSales.pack()

labelProfit = tk.Label(root, textvariable=profit)
labelProfit.pack()

button_calc = tk.Button(root, text="Calculate", command=profit_calculator)
button_calc.pack()

root.mainloop()

上面的示例显示labelProSales和entry的text值始终相等，因为两者都使用相同的变量projectedSales, 作为它们的textvariable选项。