Qt QTreeWidget三态树问题

代码:

/* hello程序 hello.c */
#include <gtk/gtk.h>
gint count = 1;
void
on_button_clicked   (GtkWidget *button, gpointer userdata){
   g_print("你好，这是Hello功能的测试.   ");
   //g_print("Hello. This is a test .  ");


/* 下面这一行的输出始终不变，哪位大哥给解释以下 */
   g_print("%d\n", (gint)userdata);


   //g_print("%d\n", count);
   count = count + 1;
}
int main ( int argc, char *argv[]){
   GtkWidget *window;
   GtkWidget *button;
   gtk_init(&argc, &argv);
   window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
   g_signal_connect(G_OBJECT(window), "delete_event", G_CALLBACK(gtk_main_quit), NULL);

   gtk_window_set_title(GTK_WINDOW(window), "Hello功能实现");
   gtk_window_set_default_size(GTK_WINDOW(window), 500, 100);
   gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
   gtk_container_set_border_width(GTK_CONTAINER(window), 40);
   button = gtk_button_new_with_label("按下此按钮会在终端上显示一行信息");
   g_signal_connect(G_OBJECT(button), "clicked", G_CALLBACK(on_button_clicked), (gpointer)count);
   gtk_container_add(GTK_CONTAINER(window), button);
   gtk_widget_show(button);
   gtk_widget_show(window);
   gtk_main();

   return FALSE;
}