Python Tkinter菜单栏在判断最上面的属性时不可见

这不是对您的问题的修复，而是一种变通方法.看起来topmost属性真的很奇怪……首先，它是特定于平台的.其次，一旦设置好了，它就不仅仅是改变了.如果将另一个窗口设置为"-topmost", 1，则这两个窗口将具有相同的属性.在我找到的documentation个中，有"-topmost gets or sets whether this is a topmost window"个.我假设，一旦您调用该属性，它不仅会判断该属性，还会重新赋值，从而为您提供带有下拉菜单的奇怪行为.有趣的是，如果你在app.attributes()年前同时获得所有属性，你的下拉菜单不会受到影响.因此，您可以使用此解决方法来判断属性，并仅在必要时设置它.很可能，这不是最好的解决方案，但这是我能想到的最好的解决方案.

import tkinter as tk


def set_topmost():
    app2.attributes('-topmost', 1)
    print('window 1', app.attributes())
    print('window 2', app2.attributes())  # as you can see both windows can have the same topmost attribute
    app.attributes('-topmost', 0)  # try the behavior after commenting this out


def check_topmost():
    print(app.attributes())  # this does not affect your window/drop-down menu
    att = str(app.attributes())  # making it a string as workaround

    if "'-topmost', 1" in att:
        print('already set as topmost')
    else:
        print('switch topmost')
        app.attributes('-topmost', 1)  # this will still disrupt your drop down menu

    app.after(5000, check_topmost)  # i set it to 5 seconds to better see the effects


app = tk.Tk()
menu_bar = tk.Menu(app)
sub_menu = tk.Menu(menu_bar, tearoff=0)
sub_menu.add_command(label = 'exit', command = app.destroy)
menu_bar.add_cascade(label = "menu", menu = sub_menu)
app.config(menu = menu_bar)
app.attributes('-topmost', 1) # comment this

app2 = tk.Toplevel()
app2.geometry('500x500')

btn = tk.Button(app, text='set topmost', command=set_topmost)
btn.pack()

app.after(1000, check_topmost)
app.mainloop()