即使root被杀死，python顶层也会运行

Question

I've included some basic code below, which generates a frame, and then a toplevel made to destroy itself. A second is created after the first is destroyed.

When this application is run, while the first toplevel is waiting, if the 'X' on the main window is clicked, it kills itself and the toplevel, but then the second toplevel is created along with a generic Tk(). When that is closed I get an error: _tkinter.TclError: can't invoke "wm" command: application has been destroyed

I've tried using root.destroy() , quit() and os._exit() , but none of these completely stops the application. What can be done to completely stop any script from running after the root window is destroyed?

from tkinter import *

class Application(Frame):
    def __init__(self,master):
        Frame.__init__(self,master)
        self.L1 = Label(root,text='Hi!')
        self.L1.pack()

 def Window1():
     Wind1 = Toplevel()
     Wind1.geometry('100x100+100+100')
     Wind1.B1 = Button(Wind1,text='Close',command=Wind1.destroy)
     Wind1.B1.pack()
     Wind1.lift(aboveThis=root)
     Wind1.wait_window()

def Window2():
     Wind2 = Toplevel()
     Wind2.geometry('100x100+100+100')
     Wind2.B2 = Button(Wind2,text='Close',command=Wind2.destroy)
     Wind2.B2.pack()
     Wind2.lift(aboveThis=root)
     Wind2.wait_window()

def Close_Window():
    root.destroy()

root = Tk()
root.geometry('100x100+50+50')
root.protocol('WM_DELETE_WINDOW',Close_Window)
app = Application(root)
Window1()
Window2()
root.mainloop()

Answer 1

The exact reason for your error is caused by 2 problems. One is that both windows are not being created at start up due to the wait_window() method. The other problem is the lack of a parent being defined for your Toplevel() windows.

Take a look at the below modified code. (Note this code needs some work still but is what you need to change to fix the error)

from tkinter import *

class Application(Frame):
    def __init__(self,master):
        Frame.__init__(self,master)
        self.L1 = Label(root, text='Hi!')
        self.L1.pack()

def Window1():
    Wind1 = Toplevel(root)
    Wind1.geometry('100x100+100+100')
    Wind1.B1 = Button(Wind1,text='Close',command=Wind1.destroy)
    Wind1.B1.pack()
    Wind1.lift(aboveThis=root)
    #Wind1.wait_window()

def Window2():
    Wind2 = Toplevel(root)
    Wind2.geometry('100x100+100+100')
    Wind2.B2 = Button(Wind2,text='Close',command=Wind2.destroy)
    Wind2.B2.pack()
    Wind2.lift(aboveThis=root)
    #Wind2.wait_window()

def Close_Window():
    root.destroy()

root = Tk()
root.geometry('100x100+50+50')
root.protocol('WM_DELETE_WINDOW',Close_Window)
app = Application(root)
Window1()
Window2()
root.mainloop()

I think you would benifit more from moving everything into a class. This way you can use class attributes to manage all data within the application including those you get from Toplevel() widgets.

import tkinter as tk


class Application(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.geometry('100x100+50+50')
        self.protocol('WM_DELETE_WINDOW', self.close_window)
        self.L1 = tk.Label(self, text='Hi!')
        self.L1.pack()
        tk.Button(self, text="Window 1", command=self.window1).pack()
        tk.Button(self, text="Window 2", command=self.window2).pack()

    def window1(self):
        wind1 = tk.Toplevel(self)
        wind1.geometry('100x100+100+100')
        wind1.B1 = tk.Button(wind1, text='Close', command=wind1.destroy).pack()

    def window2(self):
        wind2 = tk.Toplevel(self)
        wind2.geometry('100x100+100+100')
        wind2.B2 = tk.Button(wind2, text='Close', command=wind2.destroy).pack()

    def close_window(self):
        self.destroy()


app = Application()
app.mainloop()