glib GNotification没有显示图标

Question

我正试图通过GNotification显示通知：

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gtk/gtk.h>

#define ICON_PATH "/path/trash_16x16.gif"

int main(int argc, char *argv[]) {
GApplication *app;
app = g_application_new ("org." PACKAGE, G_APPLICATION_FLAGS_NONE);
if (!app) {
    g_print ("Error app\n");
} else {

    if (g_application_register (app, NULL, NULL)) {
        GNotification *notification;
        GFile *file;
        GIcon *icon;
        notification = g_notification_new (PACKAGE);
        g_notification_set_body (notification, "Hello world");
        file = g_file_new_for_path (ICON_PATH);
        icon = g_file_icon_new (file);
        g_notification_set_icon (notification, G_ICON (icon));
        g_application_send_notification (app, NULL, notification);
        g_object_unref (icon);
        g_object_unref (file);
        g_object_unref (notification);
        g_object_unref (app);
        g_print ("yes!\n");
    } else {
        g_print ("ok, no luck\n");
    }
}
return 0;

}

上面的代码正确显示了通知中的标题和正文，但是图标没有显示，有什么想法吗？