numerical buttons labels cont'd

[Pierre CHATEL <addicted2 wanadoo fr>]

Hi,

i have changed my code the way indicated in the mailing list but it's
not working...

The on_button_click_event2 callback decrements the label (numerical
value) of a button by 1, but the new value is not showing in 
the button ! The line bellow is probably incriminated:

gtk_label_set(GTK_LABEL(GTK_BIN(button)->child), str);

But when i use a constant string in place of str it's working:

gtk_label_set(GTK_LABEL(GTK_BIN(button)->child), "xx");
The above line change the label of the button to xx ON THE SCREEN

How can i use a char* in order to manipulate the label ?

/* Code Segment */

button1 = gtk_button_new_with_label (_("4"));
gtk_widget_ref (button1);
gtk_object_set_data_full (GTK_OBJECT (window1), "button1",
button1,(GtkDestroyNotify) gtk_widget_unref);
gtk_widget_show (button1);
gtk_fixed_put (GTK_FIXED (fixed1), button1, 48, 144);
gtk_widget_set_uposition (button1, 48, 144);
gtk_widget_set_usize (button1, 47, 22);

gtk_signal_connect (GTK_OBJECT (button1), "clicked",
                    GTK_SIGNAL_FUNC (on_button_click_event2),
                    NULL);

/* The callback: decrement the label of the button (default "4") by 1 */

void
on_button_click_event2 (GtkWidget *button, gpointer user_data)
{
  char *str;
  int i;
  gtk_label_get(GTK_LABEL(GTK_BIN(button)->child), &str);
  i = atoi(str);
  i--;
  sprintf(str,"%i",i);
  g_print("%s",str); /* The new value is displayed for debugging */
  gtk_label_set(GTK_LABEL(GTK_BIN(button)->child), str);
}


Thks,
Pierre