<s>[INST] import tkinter as tk
from tkinter import ttk, filedialog

class Application(tk.Tk):
    def __init__(self):
        super().__init__()
        self.title('Tkinter File Dialog')
        self.geometry('250x100')
        self.withdraw()
        self.filedialog()

    def filedialog(self):
        self.filename = filedialog.askopenfilename()
        # Rest of the code...

root = Application()
root.mainloop()

On clicking the OK button in the file dialog, the dialog disappears but the application window remains hidden.

I'm assuming that the application window is hidden because `self.withdraw()` is called in the `__init__` method.  However, I want the application window to be visible when the OK button is clicked, so I've moved `self.withdraw()` to just before the file dialog is called.  However, this doesn't seem to work.

How can I achieve this functionality?[/INST]