toolbuttons and icons

[Philippe Leroux <leroux00 yahoo fr>]

Hy there,

i'm converting an app from gtkmm 2.2 to 2.4

i can't get icons to work in toolbuttons
 
currently i have the following (after having a look at how glade creates
the code)

Glib::RefPtr<Gdk::PixbufLoader>_toolbutton_img=Gdk::PixbufLoader::create(std::string("../icons/sphere.svg"),false);
Gtk::Image *toolbutton_img = Gtk::manage(new class
Gtk::Image(_toolbutton_img->get_pixbuf()));
   _toolbutton_img=Glib::RefPtr<Gdk::PixbufLoader>();
Gtk::ToolButton* toolbuttontmp = Gtk::manage(new class
		Gtk::ToolButton(*toolbutton_img,iM->Name));		
				
executing the program leads to 

terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_S_construct NULL not valid
Aborted

the Gtk::Image(image_file) leads to the same error

I presume i'mn missing something but couldn't figure what

it used to work fine with the provided functions in gtkmm 2.2 

isn't there a function like for the button widget
	button.add_pixlabel(pixmap_file, "label");
I couldn't find anything in the documentation

Thanks in advance

Philippe L.

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