#include <gtk/gtk.h>#include <answer.h> void do_button1(GtkWidget *widget,gpointer data ){    } void do_button2(GtkWidget *widget,gpointer data ){    answer();} void call(){    GtkWidget *window;    GtkWidget *button1;    GtkWidget *button2;    GtkWidget *label;    GtkWidget *fixed = gtk_fixed_new();   window=gtk_window_new(GTK_WINDOW_TOPLEVEL);   gtk_window_set_title (GTK_WINDOW (window),"call system");   gtk_window_set_position(GTK_WINDOW(window),GTK_WIN_POS_CENTER_ALWAYS );      //窗体居中   gtk_window_set_default_size(GTK_WINDOW(window),420,490);   button1= gtk_button_new_with_label("Statement");             gtk_widget_set_size_request(button1,250,50);   button2= gtk_button_new_with_label("call");          gtk_widget_set_size_request(button2,250,300);    g_signal_connect (G_OBJECT(button1),"clicked",G_CALLBACK(do_button1),(gpointer)window);   g_signal_connect (G_OBJECT(button2),"clicked",G_CALLBACK(do_button2),(gpointer)window);   label=gtk_label_new("        call system");   gtk_widget_set_size_request(label,250,50);	      gtk_fixed_put(GTK_FIXED(fixed),button1,85, 25);   gtk_fixed_put(GTK_FIXED(fixed),button2,85, 100);   gtk_fixed_put(GTK_FIXED(fixed),label,85,415);    gtk_container_add(GTK_CONTAINER(window),fixed);   gtk_widget_show_all(window);    gtk_main ();}