简单工厂模式

 

 

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;
        }
    }
}