C#源代码23个设计程序

// Abstract Factory // Intent: "Provide an interface for creating families of related or // dependent objects without specifying their concrete classes". // For further information, read "Design Patterns", p87, Gamma et al., // Addison-Wesley, ISBN:0-201-63361-2 /* Notes: * When the construction needed involves many objects, possible organised * in multi-faceted arrangements, the entire construction can be delegated * to an abstract factory. This exposes standardised creation functionality * which can be customised in concrete implementation to suit your specific * needs, and avoid embedding this information in higher level code - it * just needs to know how to call the abstract factory. * * In this sample, we have a framework with three abstract operating classes, * called DPDocument, DPWorkspace and DPView and one abstract construction * class, called DPFactory. An application-level class, called DPApplication * is responsible for construction. * * We have a series of application-level operating classes derived from this * framework - MyDocument, MyWorkspace and MyView. For design reasons we * assume we wish to instantiate these from inside DPApplication. As there * are multiple objects needed and they could be arranged in different * lattices, we use a factory, MyFactory (in our example, there are all * simple siblings), which is called inside DPApplication. * */ 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; } } }