C# 设计模式系列教程-装饰模式

 /// <summary>
 /// 定义一个对象接口，可以给这些对象动态地添加职责
 /// </summary>
 public abstract class Component
 {
  public abstract void Opration();
 }

 /// <summary>
 /// 具体对象
 /// </summary>
 public class ConcreteComponent:Component
 {

  public override void Opration()
  {
   // 具体对象的操作
  }
 }

 /// <summary>
 /// 抽象的装饰类，它不能初始化对象。
 /// </summary>
 public abstract class Decorator:Component
 {
  protected Component component;

  /// <summary>
  /// 设置Component
  /// </summary>
  /// <param name="component"></param>
  public void SetComponent(Component component)
  {
   this.component = component;
  }

  /// <summary>
  /// 重写Operation，实际执行的是Component的Operation。
  /// </summary>
  public override void Opration()
  {
   if (component != null)
   {
    component.Opration();
   }
  }
 }

 public class ConcreteDecoratorA : Decorator
 {
  private void SpecialOpration()
  {
   // 本类特有的功能
  }

  public override void Opration()
  {
   //首先运行原Component的Operation(),在执行本类的功能，相当于对原Component进行了装饰
   base.Opration();

   this.SpecialOpration();
  }
 }

 public class ConcreteDecoratorB : Decorator
 {
  private void SpecialOprationA()
  {
   // 本类特有的功能 A
  }

  private void SpecialOprationB()
  {
   // 本类特有的功能 B
  }

  public override void Opration()
  {
   //首先运行原Component的Operation(),在执行本类的功能，相当于对原Component进行了装饰
   base.Opration();

   this.SpecialOprationA();
   this.SpecialOprationB();
  }
 }

 /// <summary>
 /// 装备类，相当于Component
 /// </summary>
 public abstract class Equipment
 {

  public abstract void Attack();
 }

 /// <summary>
 /// 士兵类，继承自Equipment
 /// </summary>
 public class Soldier : Equipment
 {
  public Soldier()
  {
   // 构造函数
  }

  /// <summary>
  /// 没有任何武器装备下的核心功能
  /// </summary>
  public override void Attack()
  {
   Console.WriteLine("用拳脚攻击！");
  }
 }

 public abstract class EquipDecorator : Equipment
 {
  protected Equipment equipment;

  /// <summary>
  /// 增加装备，使用该方法来动态地给士兵增加装备
  /// </summary>
  /// <param name="equipment"></param>
  public void SetComponent(Equipment equipment)
  {
   this.equipment = equipment;
  }

  /// <summary>
  /// 攻击
  /// </summary>
  public override void Attack()
  {
   //如果有装备，就用装备进行攻击
   if (equipment != null)
   {
    equipment.Attack();
   }
  }
 }

 /// <summary>
 /// 步枪
 /// </summary>
 public class RifleEquipment : EquipDecorator
 {
  public override void Attack()
  {
   base.Attack();

   Console.WriteLine("步枪射击，啪！");
  }
 }

 /// <summary>
 /// 机枪
 /// </summary>
 public class MachineGunEquipment : EquipDecorator
 {
  public override void Attack()
  {
   base.Attack();

   Console.WriteLine("机枪扫射，突突突！");
  }
 }

 /// <summary>
 /// 火箭筒
 /// </summary>
 public class RocketGunEquipment : EquipDecorator
 {
  public override void Attack()
  {
   base.Attack();

   Console.WriteLine("火箭炮射击，唰......！");
  }
 }

 class Program
 {
  static void Main(string[] args)
  {
   // 定义新兵
   Soldier soldier = new Soldier();

   // 三种装备
   RifleEquipment rifle = new RifleEquipment();
   MachineGunEquipment machineGun = new MachineGunEquipment();
   RocketGunEquipment rocketGun = new RocketGunEquipment();

   // 将三种装备全部交给新兵
   rifle.SetComponent(soldier);
   machineGun.SetComponent(rifle);
   rocketGun.SetComponent(machineGun);

   // 攻击，除了拳脚功夫外，新兵还可以使用步枪，机枪，火箭炮.最终执行的是rocketGun.Attack().
   rocketGun.Attack();

   Console.Read();
  }
 }