每次打开一个新的窗口，我如何关闭旧窗口？

Question

下面有一个简化的代码，由两个单独的屏幕组成。我怎样才能在打开一个屏幕时，关闭旧屏幕呢？

虽然在本例中我没有多个屏幕，但我希望能够对依赖于GUI设计的6-9个屏幕做到这一点。

如果能在这个问题上提供任何帮助，我们将不胜感激。

from tkinter import *
import os
import time
from tkinter import simpledialog

def login():
    global screen2
    screen2 = Toplevel(screen)
    screen2.title("Login")
    screen2.geometry("530x290")
    Label(screen2, text = "please enter details below to login").pack()
    Label(screen2, text = "").pack()
   
    calibration1 = StringVar()
    calibration2 = StringVar()
    calibration3 = StringVar()
   
    global calibration1_entry
    global calibration2_entry
    global calibration3_entry
   
    calibration1_entry= Entry(screen2, textvariable = calibration1).place(x=350, y=70)
    calibration2_entry = Entry(screen2, textvariable = calibration2).place(x=350, y=120)
    calibration3_entry = Entry(screen2, textvariable = calibration3).place(x=350, y=170)

def main_screen():
    global screen
    screen = Tk()
    screen.geometry("530x290")
    screen.title("Remote Monitoring Site 1")
    Label(text = "Remote Monitoring Site 1", bg = "grey", width = "300", height = "2", font = ("Calibri", 13)).pack()
    Label(text = "").pack()
    Button(text = "Login", width = "30", height = "2", command = login).pack()
    Label(text = "").pack()
   
    screen.mainloop()

main_screen()

Answer 1

您可以在开始时将screen2指定为None，如果它不是None，则确保销毁并重新打开它

def login():
    global screen2

    if screen2 is None: # if screen2 is not Toplevel
        screen2 = Toplevel(screen)
    else:
        screen2.destroy() # destroy and start new screen
        screen2 = Toplevel(screen)
    ...
    ...

def main_screen():
    global screen2,screen

    screen = Tk()
    screen2 = None # Assign to None at the beginning
    ...
    ...

这还将确保没有两个Toplevel同时打开。

Answer 2

您可以制作多个脚本，例如在一个脚本中编写登录屏幕代码，在另一个脚本中编写主菜单，然后使用import os关闭和打开脚本。函数将类似于：

def login():
    if username == "admin" and password == "admin":
        file = 'python3 main_menu.py' # or you can do it
        root.destroy()                # proper way with db
        os.system(file)