Python & Tkinter。 我希望循环中的一个按钮在按下一次时变为红色并保持红色

Question

Good morning,

I have have a little query & don't seem to be able to see anything on stack overflow which answers my question. I have attached a test script below. What I would like to happen is when the "Shift" button in my loop is pressed the background of the "Shift" button goes red & stays red. However if the shift button is pressed again I would like the background of the "Shift" button to go back to white.

Thank you in advance, see the test code below.

import tkinter as tk

window = tk.Tk()
CommandList = ["BckSpace", "Shift", "Space", "Enter"]
ShiftKey = False

for i in range (len(CommandList)):
    CommandBtn = tk.Button(window, width= 5, height = 1, text = CommandList[i], command = lambda x = i: CommandFunc(x))
    CommandBtn.pack()


def CommandFunc(x):
    global ShiftKey
    if x == 0:
        pass

    if x == 1:
        if ShiftKey == False:
            ShiftKey = True
            #Background of only button "shift" to go red and stay red
            

        else:
            ShiftKey = False
            # Backgroud of button "shift" to go back to white

    if x == 2:
        pass

    if x == 3:
        pass



window.mainloop()

Answer 1

You should be passing the button instance not index to your CommandFunc . Then you can use button['text'] to check if the shift key was pressed.

Here is an example

import tkinter as tk

window = tk.Tk()
command_list = ["BckSpace", "Shift", "Space", "Enter"]
ShiftKey = False

for i in command_list:
    commandBtn = tk.Button(window, width= 5, height = 1, text = i)
    commandBtn.config(command= lambda x=commandBtn: CommandFunc(x))
    commandBtn.pack()


def CommandFunc(btn):
    global ShiftKey
    
    if btn['text'] == command_list[1]:
        if ShiftKey == False:  # or btn['bg'] == 'red'
            ShiftKey = True
            btn['bg'] = 'red'
            

        else:
            
            ShiftKey = False
            btn['bg'] = 'white' # or 'SystemButtonFace' if you want the orginal color


window.mainloop()

_{A small suggestion would be to name your variables and function following PEP guidelines}