[C#] delegate callback

    class App
    {
            UI ui = new UI();
            Hud hud = new Hud();

        public App()
        {
            Hero hero = new Hero(20);
            hero.StepOnTrap(3, StepOnTrapHandler);
        }

        private void StepOnTrapHandler(float per)
        {
            this.ui.UpdateHeroHpGauge(per);
            this.hud.UpdateHeroHpGauge(per);
        }
    }

    class Hero
    {
        private int maxHp;
        private int hp;

        public delegate void Del(float hp);

        public Hero(int hp)
        {
            this.maxHp = hp;
            this.hp = hp;
        }

        public void StepOnTrap(int damage, Del callback)
        {
            this.hp -= damage;
            float per = (float)hp / maxHp;
            callback(per);
        }
    }

    class UI
    {
        public void UpdateHeroHpGauge(float per)
        {
            Console.WriteLine("UI 남은 체력: {0}%", per * 100);
        }
    }

    class Hud
    {
        public void UpdateHeroHpGauge(float per)
        {
            Console.WriteLine("HUD 남은 체력: {0}%", per * 100);
        }
    }

---

    class App
    {

        public App()
        {
            SCV scv = new SCV(100);
            scv.Build(BuildCompleteHandler);
        }

        void BuildCompleteHandler(int id)
        {
            Console.WriteLine("complete!: {0}", id);
        }
    }

    class SCV
    {
        int id;
        public delegate void Del(int id);

        public SCV(int id)
        {
            this.id = id;
        }

        public void Build(Del del)
        {
            del(id);
        }
    }