Visitor 表示一个作用于某个对象结构中的各元素的操作。它使你可以在不改变各元素的类的前提下定义作用于这些元素的新操作

using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6
using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6
using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6
using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6
using System;
2using System.Collections.Generic;
3using System.Text;
4
5namespace Gof.Test.Visitor
6
ObjectStructure os = new ObjectStructure();
2 os.Attach(new ConcereteElementA());
3 os.Attach(new ConcereteElementB());
4
5 //create visitor objects
6 ConcereteVisitor1 v1 = new ConcereteVisitor1();
7 ConcereteVisitor2 v2 = new ConcereteVisitor2();
8
9 //accepting visitors
10 os.Accept(v1);
11 os.Accept(v2);
12
13 Console.ReadKey();