Python Tkinter如何在框架处于活动状态时更改背景颜色

Question

i am having a problem with the following code:

def __init__(self):
    window = Tkinter.Tk()
    window.minsize(600,600)
    window.maxsize(600,600)
    window.title("test")

    #window.iconbitmap('sample.ico')

    menu_bar = Tkinter.Menu(window)

    change_color_option = Tkinter.Menu(menu_bar, tearoff=0)
    change_color_option.add_command(label = "Red", command = self.color_change(1, window))
    change_color_option.add_command(label = "Blue", command = self.color_change(2, window))
    change_color_option.add_command(label = "Yellow", command = self.color_change(3, window))
    change_color_option.add_command(label = "Green", command = self.color_change(4, window))
    change_color_option.add_command(label = "Purple", command = self.color_change(5, window))
    change_color_option.add_command(label = "Brown", command = self.color_change(6, window))

    file_menu_item = Tkinter.Menu(menu_bar, tearoff=0)
    file_menu_item.add_command(label = "Quit", command = window.quit)

    option_menu_item = Tkinter.Menu(menu_bar, tearoff=0)
    option_menu_item.add_cascade(label = "change color", menu = change_color_option)


    menu_bar.add_cascade(label="File", menu=file_menu_item)
    menu_bar.add_cascade(label="Options", menu=option_menu_item)

    window.config(menu=menu_bar)

    window.mainloop()

def color_change(self, color, window):
    if color == 1:
        window.configure(background = "#CC0000")
    elif color == 2:
        window.configure(background = "#0000CC")
    elif color == 3:
        window.configure(background = "#FFFF00")
    elif color == 4:
        window.configure(background = "#336600")
    elif color == 5:
        window.configure(background = "#660099")
    elif color == 6:
        window.configure(background = "#663300")

however my problem is that the window will take the last color (#663300) and it wont change even if i press the menu button to change color. I have to run mainloop again which is not something i want to do every time i change the color. Is there any way around it?

Answer 1

To pass an argument with the callback command, you need to use a lambda expression. Otherwise, Tkinter will perform the callback when the widget is made, which is why it's heading straight to the last value, as this is the last one the process flow reaches.

Format your lambda expressions like this:

    change_color_option.add_command(label = "Red", command = lambda: self.color_change(1, window))

More info: http://effbot.org/zone/tkinter-callbacks.htm