void show ( GtkWidget* widget )
Flags a widget to be displayed. Any widget that isn’t shown will
not appear on the screen. If you want to show all the widgets in a
container, it’s easier to call
gtk_widget_show_all() on the
container, instead of individually showing the widgets.
Remember that you have to show the containers containing a widget, in addition to the widget itself, before it will appear onscreen.
When a toplevel container is shown, it is immediately realized and mapped; other shown widgets are realized and mapped when their toplevel container is realized and mapped.