tkinter 缩放小部件的未知选项

Question

I am coding a GUI where you have to enter a number. I want to have a scale but it fits my purpose very well. The problem is a scale goes to 1e-9 precision. This is much to precise for me. I am using ttk extension for tkinter . I have tried a couple of things but I saw that there is a digits option for the scale which, when there is a StringVar() , leaves the number of digits but it doesn't work, it cannot recognise the option. I tried to look in the library but I couldn't find anything, it was too complicated.

Here is how my code is formed:

scaleValue = StringVar()
scale = ttk.Scale(content, orient=HORIZONTAL, from_=1, to=5, variable=scaleValue, length=150, digits=1)  # here digits ins't recongnised
scale.grid(column=x, row=y)

scaleValueLabel = ttk.Label(content, textvariable=scaleValue)
scaleValueLabel.grid(column=x', row=y')

Here is the documentation:

An integer specifying how many significant digits should be retained when converting the value of the scale to a string. Official Documentation : http://www.tcl.tk/man/tcl8.6/TkCmd/scale.htm

Answer 1

digits is a parameter only available to tk.Scale . If you switch to using it, then your code will work:

scale = tk.Scale(root, orient=tk.HORIZONTAL, from_=1, to=5, variable=scaleValue, length=150, digits=5)

But if you really want to use ttk.Scale , you can use a different approach. Instead of using a textvariable in your Label , you can trace the changes on your variable, process the value first, and then pass back to your Label .

import tkinter as tk
from tkinter import ttk

root = tk.Tk()

scaleValue = tk.DoubleVar()
scale = ttk.Scale(root, orient=tk.HORIZONTAL, from_=1, to=5, variable=scaleValue, length=150)  # here digits ins't recongnised
scale.grid(column=0, row=0)

scaleValueLabel = tk.Label(root, text="0")
scaleValueLabel.grid(column=0, row=1)

def set_digit(*args):
    scaleValueLabel.config(text="{0:.2f}".format(scaleValue.get()))

scaleValue.trace("w", set_digit)

root.mainloop()