How to select multiple files

[effemmeffe <effemmeffe gmail com>]

Hello, I'm using GTK3 with C on Windows.
I can compile my code with with code::blocks.
I'm trying to use a filechooser to select a bunch of files and found
gtk_file_chooser_set_select_multiple, but it seems it doesn't work.
The file chooser window shows up and I can navigate my filesystem to
the desired folder, but once there I can only select one file to open.
I'd like to select a number of files and get the filenames of those files.

Any help please?
TIA
-- 
Manuel Furio Ferrero