How to use get_window() function?

["Paulo Flabiano Smorigo" <pfsmorigo gmail com>]

Hi everyone,

I'm trying to use the get_window() function to get the window id of my gtkmm app but the function returns null.
This is the function that I'm using:

int wid;
Glib::RefPtr<Gdk::Window> wid = get_window();
wid = GDK_WINDOW_XID(Glib::unwrap(get_window()));
std::cout << "WID: " << wid << std::endl;

So, what's wrong?

Thanks!
P. F. Smorigo