如何在无需单击按钮的情况下获取 Tkinter 比例的值？

Question

如何在无需单击按钮的情况下获取 Tkinter 比例的值？

我下面的代码工作正常...但是我需要一种方法来获取值，而无需单击在我移动 Tkinter 比例尺时自动更改值的按钮。

from tkinter import *

def sel():
   selection = "Value = " + str(var.get())
   label.config(text = selection)

root = Tk()
var = DoubleVar()
scale = Scale( root, variable = var )
scale.pack(anchor=CENTER)

button = Button(root, text="Get Scale Value", command=sel)
button.pack(anchor=CENTER)

label = Label(root)
label.pack()
root.mainloop()

Answer 1

使用文本变量代替文本参数：

from tkinter import *

root = Tk()

var = DoubleVar()
scale = Scale( root, variable = var )
scale.pack(anchor=CENTER)

label = Label(root, textvariable=var)
label.pack()
root.mainloop()

Answer 2

您可以使用Scale object 中的command选项：

from tkinter import *

def sel(val=0):  # pass new scale value
   #selection = "Value = " + str(var.get())
   #label.config(text = selection)
   label.config(text = val)

root = Tk()
var = DoubleVar()
scale = Scale( root, variable = var, command=sel)  # call sel function on change
scale.pack(anchor=CENTER)

button = Button(root, text="Get Scale Value", command=sel)
button.pack(anchor=CENTER)

label = Label(root)
label.pack()
root.mainloop()