Question

我遇到以下代码的问题：

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")

然而我的问题是窗口将采用最后一种颜色（＃663300），即使按下菜单按钮改变颜色也不会改变。我必须再次运行mainloop，这不是我每次改变颜色时都想做的事情。有什么方法吗？

Answer 1

要使用callback命令传递参数，您需要使用lambda表达式。否则，Tkinter将在创建窗口小部件时执行回调，这就是它直接转到最后一个值的原因，因为这是流程流到达的最后一个值。

将lambda表达式格式化为：

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

更多信息：http://effbot.org/zone/tkinter-callbacks.htm

Python Tkinter如何在帧处于活动状态时更改背景颜色

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