运行代码：

//GUI-Menu菜单实例
#include"std_lib_facilities.h"
#include"GUI/Simple_window.h"
#include"GUI/GUI.h"
#include"GUI/Graph.h"
#include"GUI/Point.h"struct Lines_window :Window
{Lines_window(Point xy, int w, int h, const string& title);Open_polyline lines;
private:Menu color_menu;Button menu_button;Button next_button;Button quit_button;In_box next_x;In_box next_y;Out_box xy_out;void change(Color c) { lines.set_color(c); }void hide_menu() { color_menu.hide(); menu_button.show(); }static void cb_red(Address, Address);void red_pressed() { change(Color::red); hide_menu(); }static void cb_blue(Address, Address);void blue_pressed() { change(Color::blue); hide_menu(); }static void cb_black(Address, Address);void black_pressed() { change(Color::black); hide_menu(); }static void cb_menu(Address, Address);void menu_pressed() { menu_button.hide(); color_menu.show(); }static void cb_next(Address, Address);void next();static void cb_quit(Address, Address);void quit();
};Lines_window::Lines_window(Point xy, int w, int h, const string& title):Window(xy, w, h, title),color_menu(Point(x_max()-70,40),70,20,Menu::vertical,"color"),menu_button(Point(x_max()-80,30),80,20,"color menu",cb_menu),next_button(Point(x_max() - 150, 0), 70, 20, "Next point", cb_next),quit_button(Point(x_max() - 70, 0), 70, 20, "Quit", cb_quit),next_x(Point(x_max() - 310, 0), 50, 20, "next x:"),next_y(Point(x_max() - 210, 0), 50, 20, "next y:"),xy_out(Point(100, 0), 100, 20, "current(x,y):")
{color_menu.attach(new Button(Point(0, 0), 0, 0, "red", cb_red));color_menu.attach(new Button(Point(0, 0), 0, 0, "blue", cb_blue));color_menu.attach(new Button(Point(0, 0), 0, 0, "black", cb_black));attach(color_menu);attach(next_button);attach(quit_button);attach(next_x);attach(next_y);attach(xy_out);xy_out.put("no point");color_menu.hide();attach(menu_button);lines.set_color(Color::black);attach(lines);
}void Lines_window::cb_red(Address, Address pw)
{reference_to<Lines_window>(pw).red_pressed();
}void Lines_window::cb_blue(Address, Address pw)
{reference_to<Lines_window>(pw).blue_pressed();
}void Lines_window::cb_black(Address, Address pw)
{reference_to<Lines_window>(pw).black_pressed();
}void Lines_window::cb_menu(Address, Address pw)
{reference_to<Lines_window>(pw).menu_pressed();
}void Lines_window::cb_quit(Address, Address pw)
{reference_to<Lines_window>(pw).quit();
}void Lines_window::quit()
{hide();
}void Lines_window::cb_next(Address, Address pw)
{reference_to<Lines_window>(pw).next();
}void Lines_window::next()
{int x = next_x.get_int();int y = next_y.get_int();lines.add(Point(x, y));stringstream ss;ss << '(' << x << ',' << y << ')';xy_out.put(ss.str());redraw();
}int main()
try
{Lines_window win(Point(100, 100), 600, 400, "lines");return gui_main();
}
catch (exception& e) {cerr << "error:" << e.what() << '\n';keep_window_open();return 1;
}
catch (...) {cerr << "Oops:unknown exception!\n";keep_window_open();return 2;
}

运行结果：