Design Mode note-factory method mode

Factory Method: defines an interface used to create objects, so that the subclass decides to instantiate the class. The Factory Method extends the instantiation of a class to its subclass.

UML class diagram:

The basic code for the factory method mode is as follows:

/*************************************** * **************************** Filename: factorymethod. hcreated: 2012-09-21author: firehoodpurpose: design Mode of firehood-factory method mode ******************************* **************************************/# pragma once # include <iostream> using namespace STD; // abstract product class product {public: product () {} virtual ~ Product () {}}; // specific product Aclass concreteproducta: Public Product {public: concreteproducta () {cout <"production product a" <Endl;} virtual ~ Concreteproducta () {cout <"Destroy product a" <Endl ;}}; // product-specific bclass concreteproductb: Public Product {public: concreteproductb () {cout <"production product B" <Endl;} virtual ~ Concreteproductb () {cout <"Destroy product B" <Endl ;};// abstract factory class creator {public: creator () {}; virtual ~ Creator () {}; product * createproduct () {return factorymethod () ;}protected: Virtual Product * factorymethod () = 0 ;}; // specific factory Aclass concretecreatora: public creator {public: concretecreatora () {cout <"create factory a" <Endl;} virtual ~ Concretecreatora () {cout <"Destroy factory a" <Endl;} protected: Virtual Product * factorymethod () {return New concreteproducta ();}}; // The actual factory bclass concretecreatorb: Public creator {public: concretecreatorb () {cout <"create factory B" <Endl;} virtual ~ Concretecreatorb () {cout <"Destroy factory B" <Endl;} protected: Virtual Product * factorymethod () {return New concreteproductb ();}};

Client call code:

Int main (int argc, char * argv []) {cout <"*********************************** ** "<endl; cout <"firehood learning design model-factory method model" <endl; cout <"************************************ * "<endl; creator * factoryA = new ConcreteCreatorA (); Product * productA = factoryA-> CreateProduct (); Creator * factoryB = new ConcreteCreatorB (); Product * productB = factoryB-> CreateProduct (); delete productA; delete factoryA; delete productB; delete factoryB; system ("pause"); return 0 ;}

Running result:

*************************************
Firehood learning design model-factory method model
*************************************
Create Factory
Production product
Create factory B
Production product B
Destroy product
Destruction plant
Destroy product B
Destroy factory B

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