The Abstract Factory Pattern provides an interface for creating families of related or dependent objects without specifying their concrete classes.
Definition - AbstractFactory and ConcreteFactory
public interface PizzaIngredientFactory
{
Dough CreateDough();
}
public class AmericanPizzaIngredientFactory : PizzaIngredientFactory
{
public Dough CreateDough()
{
return new ThickCrustDough();
}
}
public class ItalianPizzaIngredientFactory : PizzaIngredientFactory
{
public Dough CreateDough()
{
return new ThinCrustDough();
}
}Definition - AbstractProduct and ConcreteProduct
public interface Dough
{
string GetName();
}
public class ThickCrustDough : Dough
{
public string GetName()
{
return "Extra thick crust dough";
}
}
public class ThinCrustDough : Dough
{
public string GetName()
{
return "Thin crust dough";
}
}
Usage
public class AmericanPizzaStore : PizzaStore
{
// AmericanPizzaStore creates the corresponding ingriedient factory.
private PizzaIngredientFactory ingredientFactory = new AmericanPizzaIngredientFactory();
protected override Pizza CreatePizza(PizzaType type)
{
switch (type)
{
case PizzaType.Cheese:
// the correct ingredientFactory is transferred when creating a pizza
return new CheesePizza(ingredientFactory);
case PizzaType.Veggie:
return new VeggiePizza(ingredientFactory);
default:
throw new NotImplementedException();
}
}
}
- AbstractFactory (PizzaIngredientFactory)
- declares an interface for operations that create abstract products
- ConcreteFactory (ItalianPizzaIngredientFactory, AmericanPizzaIngredientFactory)
- implements the operations to create concrete product objects
- AbstractProduct (Dough)
- declares an interface for a type of product object
- ConcreteProduct(ThinCrustDough, ThickCrustDough)
- defines a product object to be created by the corresponding concrete factory
- implements the AbstractProduct interface
[Source: http://www.dofactory.com/net/abstract-factory-design-pattern]