设计模式之生成器模式

abstract class PizzaBuilder {

   protected Pizza Pizza;

   public Pizza GetPizza() {
      return this.Pizza;
   }

   public void CreateNewPizzaProduct() {
      this.Pizza = new Pizza();
   }

   public abstract void BuildDough();

   public abstract void BuildSauce();

   public abstract void BuildTopping();

}

class HawaiianPizzaBuilder : PizzaBuilder {

   public override void BuildDough() {
      this.Pizza.Dough = "cross";
   }

   public override void BuildSauce() {
      this.Pizza.Sauce = "mild";
   }

   public override void BuildTopping() {
      this.Pizza.Topping = "ham+pineapple";
   }
}

class SpicyPizzaBuilder : PizzaBuilder {

   public override void BuildDough() {
      this.Pizza.Dough = "pan baked";
   }

   public override void BuildSauce() {
      this.Pizza.Sauce = "hot";
   }

   public override void BuildTopping() {
      this.Pizza.Topping = "pepperoni + salami";
   }
}

class Cook {

   private PizzaBuilder _pizzaBuilder;

   public void SetPizzaBuilder(PizzaBuilder pb) {
      _pizzaBuilder = pb;
   }

   public Pizza GetPizza() {
      return _pizzaBuilder.GetPizza();
   }

   public void ConstructPizza() {
      _pizzaBuilder.CreateNewPizzaProduct();
      _pizzaBuilder.BuildDough();
      _pizzaBuilder.BuildSauce();
      _pizzaBuilder.BuildTopping();
   }
}

public class Pizza {

   private string _dough = string.Empty;
   private string _sauce = string.Empty;
   private string _topping = string.Empty;

   public string Dough {
      get {
         return _dough;
      }
      set {
         _dough = value;
      }
   }

   public string Sauce {
      get {
         return _sauce;
      }
      set {
         _sauce = value;
      }
   }

   public string Topping {
      get {
         return _topping;
      }
      set {
         _topping = value;
      }
   }
}

class Program {

   static void Main(string[] args) {
      PizzaBuilder hawaiianPizzaBuilder = new HawaiianPizzaBuilder();
      var cook = new Cook();
      cook.SetPizzaBuilder(hawaiianPizzaBuilder);
      cook.ConstructPizza();
      // create the product
      var hawaiian = cook.GetPizza();

      PizzaBuilder spicyPizzaBuilder = new SpicyPizzaBuilder();
      cook.SetPizzaBuilder(spicyPizzaBuilder);
      cook.ConstructPizza();
      // create another product
      var spicy = cook.GetPizza();
   }

}