黑暗模式不工作，我在tkinter文本小部件中建立

Question

实际上我正在制作一个记事本，我制作了一个按钮，可以改变文本小部件的颜色。但它既不起作用，也不会出错。有人能解释一下为什么这不能解决问题吗？

from tkinter import *
import tkinter.messagebox as tmsg
from tkinter import ttk

root = Tk()
root.geometry('450x500')
root.title('my notepad')
fonts = ['lucida','Arial']
fg_col,bg_col = 'black','white'
def darkmode():
global fg_col,bg_col
fg_col,bg_col='white','black'
Button(root,text='DARK Theme',bg = 'grey',command=darkmode).pack()
text = Text(root,font =(f'{fonts[0]}',18,'bold'),foreground = fg_col,background=bg_col).pack()

root.mainloop()

Answer 1

只需准备两种模式并将其用作kwargs。我让你从一些比前景和背景颜色更全面的东西开始。

import tkinter as tk
root = tk.Tk()
root.geometry('450x500')
root.configure(bg='grey60')
root.title('my notepad')
#prepare base kwargs
common = dict(
font               = 'arial 18 bold',
borderwidth        = 0,
wrap               = 'word',    #or 'char', 'none'
relief             = 'flat',
tabs               = '1c',
highlightthickness = 2,
insertwidth        = 4,         #fat caret
insertofftime      = 600,       #caret slow blink
insertontime       = 1200,
padx               = 10,        #thick padding
pady               = 10,
blockcursor        = False      #make True for really fat cursor
)
#prepare light kwargs
lightmode = dict(
foreground          = 'black',
background          = 'white',
insertbackground    = 'black',  #caret color
selectforeground    = 'white',  #when text is selected
selectbackground    = 'black',  #~
highlightbackground = 'gray40', #highlight color when Text does NOT have focus
highlightcolor      = 'gray80', #highlight color when Text has focus
)
#prepare dark kwargs
darkmode = dict(
foreground          = 'white',
background          = 'black',
insertbackground    = 'white',  #caret color
selectforeground    = 'black',  #when text is selected
selectbackground    = 'white',  #~
highlightbackground = 'gray80', #highlight color when Text does NOT have focus
highlightcolor      = 'gray40', #highlight color when Text has focus
)
#not used but acts as an example 
#that you can just keep copy/pasting these things
#and changing values
mcdonaldsmode = dict(
foreground          = 'yellow',
background          = 'red',
insertbackground    = 'yellow',  #caret color
selectforeground    = 'red',     #when text is selected
selectbackground    = 'yellow',  #~
highlightbackground = 'red',     #highlight color when Text does NOT have focus
highlightcolor      = 'yellow',  #highlight color when Text has focus
)
#toggle modes
def toggle():
text.basemode = not text.basemode
text.configure(**lightmode) if text.basemode else text.configure(**darkmode) 

tk.Button(root, text='Switch Theme', bg='grey60', fg='grey100', command=toggle).pack(anchor='e')
text = tk.Text(root, **lightmode, **common)
text.basemode = True #invent a switch to toggle
text.pack()
root.mainloop()

Answer 2

与其编辑变量fg_col,bg_col，不如配置小部件：

def darkmode():
text.config(foreground="white", background='black')