+using GLib;
+using Gtk;
+
+
+static void main (string[] args) {
+ Gtk.init (ref args);
+
+ var window_main = new Window();
+ window_main.title = "Hello world!";
+ window_main.set_default_size (200, 200);
+ window_main.destroy.connect (Gtk.main_quit);
+
+ var vbox_main = new Box (Orientation.VERTICAL, 0);
+
+ lbl_hello = new Label ("Hello!");
+ var btn_bye = new Button.with_label ("Magic!");
+
+ btn_bye.clicked.connect (on_btn_bye_clicked);
+
+ vbox_main.pack_start (lbl_hello, true, true);
+ vbox_main.pack_start (btn_bye, false, true);
+
+ window_main.add (vbox_main);
+
+ window_main.show_all();
+
+ Gtk.main();
+}
+
+static void on_btn_bye_clicked() {
+ lbl_hello.label = "Bye!";
+}