<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Visitor Pattern.aspx.cs" Inherits="Pattern_Visitor_Pattern" %>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="tb_result" runat="server" TextMode="MultiLine" Rows="5" Width="400px"></asp:TextBox>
<asp:Button ID="bt_submit" runat="server" OnClick="bt_submit_Click" Text="VisitorPattern" />
<select id="strategy_select" runat="server">
<option value="A" selected="selected">A</option>
<option value="B">B</option>
</select>
</div>
</form>
</body>
</html>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:TextBox ID="tb_result" runat="server" TextMode="MultiLine" Rows="5" Width="400px"></asp:TextBox>
<asp:Button ID="bt_submit" runat="server" OnClick="bt_submit_Click" Text="VisitorPattern" />
<select id="strategy_select" runat="server">
<option value="A" selected="selected">A</option>
<option value="B">B</option>
</select>
</div>
</form>
</body>
</html>
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
/// <summary>
/// 觀察者模式
/// 好處:把訪問者和訪問的內容獨立,這樣訪問者只管訪問,需要訪問那些內容,有另外一個類去實現,這樣,當訪問的內容有變化時,只需要調整控制訪問對象的類就可以了!具有很好的擴展性和可維護性!
/// 缺點:沒新增一個新的訪問內容(節點),都需要在'訪問對象的抽象類'中增加一個新的方法.另外,訪問者訪問節點內容的時候,必須知道內部操作方法和一些屬性狀態,因襲,封裝性不是很好.
/// </summary>
public partial class Pattern_Visitor_Pattern : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
private void VisitorFactory()
{
Context ttt = null;
switch (strategy_select.Items[strategy_select.SelectedIndex].Value.ToString())
{
case "A":
ConcreteVisitorA VA = new ConcreteVisitorA();
tb_result.Text = VA.VisitorAccessObjectA(new AccessObjectA()) + " \n" + VA.VisitorAccessObjectB(new AccessObjectB());
break;
case "B":
ConcreteVisitorB VB = new ConcreteVisitorB();
tb_result.Text = VB.VisitorAccessObjectA(new AccessObjectA()) + " \n" + VB.VisitorAccessObjectB(new AccessObjectB());
break;
default:
tb_result.Text = "請選擇
";
break;
}
}
protected void bt_submit_Click(object sender, EventArgs e)
{
VisitorFactory();
}
}
/// <summary>
/// 先定義一個訪問者
/// </summary>
public abstract class Visitor
{
public abstract string VisitorAccessObjectA(AccessObjectA accessobjecta);
public abstract string VisitorAccessObjectB(AccessObjectB accessobjectb);
}
/// <summary>
/// 定義一個訪問對象的抽象類
/// </summary>
public abstract class AccessObject
{
public abstract string GetVisitorName();
}
public class AccessObjectA : AccessObject
{
public override string GetVisitorName()
{
return "ObjectA";
}
public string OperatorA()
{
return "OperatorA";
}
}
public class AccessObjectB : AccessObject
{
public override string GetVisitorName()
{
return "ObjectB";
}
public string OperatorB()
{
return "OperatorB";
}
}
/// <summary>
/// 實現Visitor A類
/// </summary>
public class ConcreteVisitorA:Visitor
{
public override string VisitorAccessObjectA(AccessObjectA accessobjecta)
{
return accessobjecta.GetVisitorName() +" visited by "+this;
}
public override string VisitorAccessObjectB(AccessObjectB accessobjectb)
{
return accessobjectb.GetVisitorName() + " visited by " + this;
}
}
/// <summary>
/// 實現Visitor B類
/// </summary>
public class ConcreteVisitorB : Visitor
{
public override string VisitorAccessObjectA(AccessObjectA accessobjecta)
{
return accessobjecta.GetVisitorName() + " visited by " + this;
}
public override string VisitorAccessObjectB(AccessObjectB accessobjectb)
{
return accessobjectb.GetVisitorName() + " visited by " + this;
}
}
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
/// <summary>
/// 觀察者模式
/// 好處:把訪問者和訪問的內容獨立,這樣訪問者只管訪問,需要訪問那些內容,有另外一個類去實現,這樣,當訪問的內容有變化時,只需要調整控制訪問對象的類就可以了!具有很好的擴展性和可維護性!
/// 缺點:沒新增一個新的訪問內容(節點),都需要在'訪問對象的抽象類'中增加一個新的方法.另外,訪問者訪問節點內容的時候,必須知道內部操作方法和一些屬性狀態,因襲,封裝性不是很好.
/// </summary>
public partial class Pattern_Visitor_Pattern : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
private void VisitorFactory()
{
Context ttt = null;
switch (strategy_select.Items[strategy_select.SelectedIndex].Value.ToString())
{
case "A":
ConcreteVisitorA VA = new ConcreteVisitorA();
tb_result.Text = VA.VisitorAccessObjectA(new AccessObjectA()) + " \n" + VA.VisitorAccessObjectB(new AccessObjectB());
break;
case "B":
ConcreteVisitorB VB = new ConcreteVisitorB();
tb_result.Text = VB.VisitorAccessObjectA(new AccessObjectA()) + " \n" + VB.VisitorAccessObjectB(new AccessObjectB());
break;
default:
tb_result.Text = "請選擇
";break;
}
}
protected void bt_submit_Click(object sender, EventArgs e)
{
VisitorFactory();
}
}
/// <summary>
/// 先定義一個訪問者
/// </summary>
public abstract class Visitor
{
public abstract string VisitorAccessObjectA(AccessObjectA accessobjecta);
public abstract string VisitorAccessObjectB(AccessObjectB accessobjectb);
}
/// <summary>
/// 定義一個訪問對象的抽象類
/// </summary>
public abstract class AccessObject
{
public abstract string GetVisitorName();
}
public class AccessObjectA : AccessObject
{
public override string GetVisitorName()
{
return "ObjectA";
}
public string OperatorA()
{
return "OperatorA";
}
}
public class AccessObjectB : AccessObject
{
public override string GetVisitorName()
{
return "ObjectB";
}
public string OperatorB()
{
return "OperatorB";
}
}
/// <summary>
/// 實現Visitor A類
/// </summary>
public class ConcreteVisitorA:Visitor
{
public override string VisitorAccessObjectA(AccessObjectA accessobjecta)
{
return accessobjecta.GetVisitorName() +" visited by "+this;
}
public override string VisitorAccessObjectB(AccessObjectB accessobjectb)
{
return accessobjectb.GetVisitorName() + " visited by " + this;
}
}
/// <summary>
/// 實現Visitor B類
/// </summary>
public class ConcreteVisitorB : Visitor
{
public override string VisitorAccessObjectA(AccessObjectA accessobjecta)
{
return accessobjecta.GetVisitorName() + " visited by " + this;
}
public override string VisitorAccessObjectB(AccessObjectB accessobjectb)
{
return accessobjectb.GetVisitorName() + " visited by " + this;
}
}
