简单工厂模式

 

 

代码

namespace  AbstractFactory_DesignPattern
{
     using  System;

     //  These classes could be part of a framework,
     //  which we will call DP
     //  ===========================================
    
     abstract   class  DPDocument 
    {
         abstract   public   void  Dump();        
    }

     abstract   class  DPWorkspace
    {
         abstract   public   void  Dump();
    }
    
     abstract   class  DPView 
    {
         abstract   public   void  Dump();
    }    
    
     abstract   class  DPFactory 
    {
         abstract   public  DPDocument CreateDocument();
         abstract   public  DPView CreateView();
         abstract   public  DPWorkspace CreateWorkspace();
    }

     abstract   class  DPApplication 
    {
         protected  DPDocument doc;
         protected  DPWorkspace workspace;
         protected  DPView view;
        
         public   void  ConstructObjects(DPFactory factory)
        {
             //  Create objects as needed
            doc  =  factory.CreateDocument();
            workspace  =  factory.CreateWorkspace();
            view  =  factory.CreateView();
        }        
        
         abstract   public   void  Dump();

         public   void  DumpState()
        {
             if  (doc  !=   null ) doc.Dump();
             if  (workspace  !=   null ) workspace.Dump();
             if  (view  !=   null ) view.Dump();
        }
    }

     //  These classes could be part of an application 
     class  MyApplication : DPApplication 
    {
        MyFactory myFactory  =   new  MyFactory();

         override   public   void  Dump()
        {
            Console.WriteLine( " MyApplication exists " );
        }

         public   void  CreateFamily()
        {
            MyFactory myFactory  =   new  MyFactory();
            ConstructObjects(myFactory);            
        }
    }    

     class  MyDocument : DPDocument 
    {
         public  MyDocument()
        {
                Console.WriteLine( " in MyDocument constructor " );            
        }
        
         override   public   void  Dump()
        {
            Console.WriteLine( " MyDocument exists " );
        }
    }

     class  MyWorkspace : DPWorkspace 
    {
         override   public   void  Dump()
        {
            Console.WriteLine( " MyWorkspace exists " );
        }
    }

     class  MyView : DPView 
    {
         override   public   void  Dump()
        {
            Console.WriteLine( " MyView exists " );
        }
    }

     class  MyFactory : DPFactory 
    {
         override   public  DPDocument CreateDocument()
        {
             return   new  MyDocument();
        }
         override   public  DPWorkspace CreateWorkspace()
        {
             return   new  MyWorkspace();
        }        
         override   public  DPView CreateView()
        {
             return   new  MyView();
        }
    }

     ///   <summary>
     ///     Summary description for Client.
     ///   </summary>
     public   class  Client
    {
         public   static   int  Main( string [] args)
        {
            MyApplication myApplication  =   new  MyApplication();

            myApplication.CreateFamily();

            myApplication.DumpState();
            
             return   0 ;
        }
    }
}