using System;
using System.Collections;
namespace DoFactory.GangOfFour.Visitor.Structural
{
??
??// MainApp test application
??class MainApp
??{
????staticvoid Main()
????{
??????// Setup structure
??????ObjectStructure o = new ObjectStructure();
??????o.Attach(new ConcreteElementA());
??????o.Attach(new ConcreteElementB());
??????// Create visitor objects
??????ConcreteVisitor1 v1 = new ConcreteVisitor1();
??????ConcreteVisitor2 v2 = new ConcreteVisitor2();
??????// Structure accepting visitors
??????o.Accept(v1);
??????o.Accept(v2);
??????// Wait for user
??????Console.Read();
????}
??}
??// "Visitor"
??abstractclass Visitor
??{
????publicabstractvoid VisitConcreteElementA(
??????ConcreteElementA concreteElementA);
????publicabstractvoid VisitConcreteElementB(
??????ConcreteElementB concreteElementB);
??}
??// "ConcreteVisitor1"
??class ConcreteVisitor1 : Visitor
??{
????publicoverridevoid VisitConcreteElementA(
??????ConcreteElementA concreteElementA)
????{
??????Console.WriteLine("{0} visited by {1}",
????????concreteElementA.GetType().Name, this.GetType().Name);
????}
????publicoverridevoid VisitConcreteElementB(
??????ConcreteElementB concreteElementB)
????{
??????Console.WriteLine("{0} visited by {1}",
????????concreteElementB.GetType().Name, this.GetType().Name);
????}
??}
??// "ConcreteVisitor2"
??class ConcreteVisitor2 : Visitor
??{
????publicoverridevoid VisitConcreteElementA(
??????ConcreteElementA concreteElementA)
????{
??????Console.WriteLine("{0} visited by {1}",
????????concreteElementA.GetType().Name, this.GetType().Name);
????}
????publicoverridevoid VisitConcreteElementB(
??????ConcreteElementB concreteElementB)
????{
??????Console.WriteLine("{0} visited by {1}",
????????concreteElementB.GetType().Name, this.GetType().Name);
????}
??}
??// "Element"
??abstractclass Element
??{
????publicabstractvoid Accept(Visitor visitor);
??}
??// "ConcreteElementA"
??class ConcreteElementA : Element
??{
????publicoverridevoid Accept(Visitor visitor)
????{
??????visitor.VisitConcreteElementA(this);
????}
????publicvoid OperationA()
????{
????}
??}
??// "ConcreteElementB"
??class ConcreteElementB : Element
??{
????publicoverridevoid Accept(Visitor visitor)
????{
??????visitor.VisitConcreteElementB(this);
????}
????publicvoid OperationB()
????{
????}
??}
??// "ObjectStructure"
??class ObjectStructure
??{
????private ArrayList elements = new ArrayList();
????publicvoid Attach(Element element)
????{
??????elements.Add(element);
????}
????publicvoid Detach(Element element)
????{
??????elements.Remove(element);
????}
????publicvoid Accept(Visitor visitor)
????{
??????foreach (Element e in elements)
??????{
????????e.Accept(visitor);
??????}
????}
??}
}
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