GTK_CALLBACK void on_toolbutton_about_clicked(GtkWidget *btn, gpointer user_data){    GtkWidget *about_dialog;    GdkPixbuf *logo;    GError *error=NULL;    const gchar *author[]={"Guan Jiaying"};    about_dialog=gtk_about_dialog_new();    logo=gdk_pixbuf_new_from_file("k.ico",&error);    if(!error)        gtk_about_dialog_set_logo(GTK_ABOUT_DIALOG(about_dialog),logo);    else    {        g_print("Error:%s\n",error->message);        g_error_free(error);    }    gtk_about_dialog_set_program_name(GTK_ABOUT_DIALOG(about_dialog),"Chinese Certification Document Editor");    gtk_about_dialog_set_version(GTK_ABOUT_DIALOG(about_dialog),"v1.0");    gtk_about_dialog_set_authors(GTK_ABOUT_DIALOG(about_dialog),author);        gtk_about_dialog_set_license(GTK_ABOUT_DIALOG(about_dialog),"Free license under Guan‘s approval");    gtk_about_dialog_set_copyright(GTK_ABOUT_DIALOG(about_dialog),"(C) 2014 Guan");        gtk_dialog_run(GTK_DIALOG(about_dialog));    gtk_widget_destroy(about_dialog);}