裝飾模式（Decorator）：動態地給一個物件新增一些額外的職責，就增加功能來說，裝飾模式比生成子類更為靈活。

就以穿衣服為例，無論是鞋子、領帶、披風都是對人的裝飾。

定義一個人類

<strong><span style="font-family:KaiTi_GB2312;"> class Person
    {
        public Person()
        { }

        private string name;
        public Person(string name)
        {
            this.name = name;
        }

        public virtual void Show()
        {
            Console.WriteLine("裝扮的{0}",name );
        }
    }</span></strong>
 

<strong><span style="font-family:KaiTi_GB2312;"> class Finery :Person 
    {
        protected Person component;

        //打扮

        public  void Decorate(Person component)
        {
            this.component = component;
        }

        public override void Show()
        {
            if (component !=null )
            {
                component.Show();
            }
        }
    }</span></strong>
 

各衣服的類

<strong><span style="font-family:KaiTi_GB2312;">//垮褲
    class BigTrouser : Finery
    {
        public override void Show()
        {
            Console.Write("垮褲");
            base.Show();
        }
    }</span></strong>

</pre><pre name="code" class="csharp"><strong><span style="font-family:KaiTi_GB2312;">//皮鞋 </span></strong>
 

<strong><span style="font-family:KaiTi_GB2312;">class LeatherShoes : Finery
    {
        public override void Show()
        {
            Console.Write("皮鞋");
            base.Show();
        }
    }</span></strong>

</pre><pre name="code" class="csharp"><strong><span style="font-family:KaiTi_GB2312;"> //破球鞋
    class Sneakers : Finery
    {
        public override void Show()
        {
            Console.Write("破球鞋");
            base.Show();
        }
    }</span></strong>

</pre><pre name="code" class="csharp"><strong><span style="font-family:KaiTi_GB2312;">//西裝 </span></strong>

<strong><span style="font-family:KaiTi_GB2312;">class Suit : Finery
    {
        public override void Show()
        {
            Console.Write("西裝");
            base.Show();
        }
    }</span></strong>

</pre><pre name="code" class="csharp"><strong><span style="font-family:KaiTi_GB2312;">//領帶</span></strong>

<strong><span style="font-family:KaiTi_GB2312;"> class Tie : Finery
    {
        public override void Show()
        {
            Console.Write("領帶");
            base.Show();
        }
    }</span></strong>

</pre><pre name="code" class="csharp"><strong><span style="font-family:KaiTi_GB2312;">//大T恤</span></strong>

<strong><span style="font-family:KaiTi_GB2312;">class Tshirts :Finery 
    {
        public override void Show()
        {
            Console.Write("大T恤");
            base.Show();
        }
    }</span></strong>

<strong><span style="font-family:KaiTi_GB2312;"> class Program
    {
        static void Main(string[] args)
        {
            Person xc = new Person("小菜");

            Console.WriteLine("\n第一種裝扮：");

            Sneakers pqx = new Sneakers();
            BigTrouser kk = new BigTrouser();
            Tshirts dtx = new Tshirts();

            pqx.Decorate(xc);
            kk.Decorate(pqx );
            dtx.Decorate(kk);
            dtx.Show();

            Console.WriteLine("\n第二種裝扮");

            LeatherShoes px = new LeatherShoes();
            Tie ld = new Tie();
            Suit xz = new Suit();

            px.Decorate(xc);
            ld.Decorate(px );
            xz.Decorate(ld );
            xz.Show();

            Console.Read();
        }
    }</span></strong>

裝飾模式把每個要裝飾的功能放在單獨的類中，並讓這個類包裝它所要裝飾的物件，當需要只想特殊行為時，客戶程式碼就可以在執行時根據需要有選擇地、按順序地使用裝飾功能包裝物件。

我理解的是，我們每個人都是一個客戶端，我們的每一件衣服就是一個已經包裝好了的類，當我們使用裝飾模式時，就相當於我們在打扮自己，我們選擇穿哪一件衣服，穿衣服的順序等等。