问tkinter中锁定和解锁的运动

EN

from tkinter import *

can_drag = False

def toggle_drag(event):
    global can_drag
    can_drag = not can_drag

def on_click(event):
    global dx, dy
    if can_drag:
        # save the distance between mouse position and the top-left corner of main window
        dx, dy = event.x_root-main.winfo_rootx(), event.y_root-main.winfo_rooty()

def on_drag(event):
    if can_drag:
        # move the main window
        main.geometry(f"+{event.x_root-dx}+{event.y_root-dy}")

main=Tk()
photo=PhotoImage(file='image.PNG')
Label(main,image=photo,bg='grey').pack()
main.wm_attributes("-transparentcolor", 'grey')
main.wm_attributes("-topmost", True)
main.overrideredirect(1)
main.bind("<Button-1>", on_click)
main.bind("<B1-Motion>", on_drag)
main.bind("<F2>", toggle_drag) # function key to lock and unlock movement
main.mainloop()