实现一个可以动态改变的N层导航树

原理：
将导航树信息存储在web.config文件中，程序获取存储在web.config中导航树的信息并生成相应的导航结构。

代码：

using System;
using System.Configuration;
using System.Collections.Generic;
using System.Collections;
using System.Xml;

/// <summary>
/// NavigateHandler 的摘要说明
/// </summary>
public class NavigateHandler:IConfigurationSectionHandler
{
	public NavigateHandler()
	{
		//
		// TODO: 在此处添加构造函数逻辑
		//
	}

    #region IConfigurationSectionHandler 成员

    public object Create(object parent, object configContext, System.Xml.XmlNode section)
    {      
 XmlNodeList nodes = section.SelectNodes("link");
        if (nodes.Count == 0)
            return null;
        Category normalUserRootCategory = new Category("root", "root");//创建根目录
        foreach (XmlNode n in nodes)
        {

            string pname, pvalue;
            pname = n.Attributes["name"].Value;
            pvalue = n.Attributes["value"].Value;
            Category parentCategory = new Category(pname, pvalue);//创建主目录
            normalUserRootCategory.AddChildCategory(parentCategory);
            XmlNodeList cnodes = n.SelectNodes("clink");
            foreach (XmlNode cn in cnodes)
            {
                string cname, cvalue;
                cname = cn.Attributes["name"].Value;
                cvalue = cn.Attributes["value"].Value;
                Category childCategory = new Category(cname, cvalue);//创建主目录下的子目录
                parentCategory.AddChildCategory(childCategory);
            }
        }
        return normalUserRootCategory.ChildCategoryCollection;

    }

    #endregion
    public static List<Category> GetCategoryList() {
        return (List<Category>)ConfigurationManager.GetSection("Navigate");
    }
}

读取web.config文件中的信息并生成相应的导航结构

<?xml version="1.0"?>
<configuration>
	<configSections>
		<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
			<sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
				<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
				<sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
					<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>
					<section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
					<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
				</sectionGroup>
			</sectionGroup>
		</sectionGroup>
		<section name="Navigate" type="NavigateHandler,App_Code"/>
	</configSections>
	<system.web>
		<pages>
			<controls>
				<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			</controls>
		</pages>
		<!--
          Set compilation debug="true" to insert debugging
          symbols into the compiled page. Because this
          affects performance, set this value to true only
          during development.
    -->
		<compilation debug="true">
			<assemblies>
				<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
				<add assembly="System.Web.Extensions.Design, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
				<add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
				<add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/></assemblies>
		</compilation>
		<httpHandlers>
			<remove verb="*" path="*.asmx"/>
			<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			<add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
		</httpHandlers>
		<httpModules>
			<add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
		</httpModules>
	</system.web>
	<system.web.extensions>
		<scripting>
			<webServices>
				<!-- Uncomment this line to customize maxJsonLength and add a custom converter -->
				<!--
      <jsonSerialization maxJsonLength="500">
        <converters>
          <add name="ConvertMe" type="Acme.SubAcme.ConvertMeTypeConverter"/>
        </converters>
      </jsonSerialization>
      -->
				<!-- Uncomment this line to enable the authentication service. Include requireSSL="true" if appropriate. -->
				<!--
        <authenticationService enabled="true" requireSSL = "true|false"/>
      -->
				<!-- Uncomment these lines to enable the profile service. To allow profile properties to be retrieved
           and modified in ASP.NET AJAX applications, you need to add each property name to the readAccessProperties and
           writeAccessProperties attributes. -->
				<!--
      <profileService enabled="true"
                      readAccessProperties="propertyname1,propertyname2"
                      writeAccessProperties="propertyname1,propertyname2" />
      -->
			</webServices>
			<!--
      <scriptResourceHandler enableCompression="true" enableCaching="true" />
      -->
		</scripting>
	</system.web.extensions>
	<system.webServer>
		<validation validateIntegratedModeConfiguration="false"/>
		<modules>
			<add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
		</modules>
		<handlers>
			<remove name="WebServiceHandlerFactory-Integrated"/>
			<add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
			<add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
		</handlers>
	</system.webServer>
	<Navigate>
		<link name="主栏目1" value="主栏目1">
			<clink name="子栏目1" value="子栏目1"></clink>
			<clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
    <link name="主栏目2" value="主栏目2">
      <clink name="子栏目1" value="子栏目1"></clink>
      <clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
    <link name="主栏目3" value="主栏目3">
      <clink name="子栏目1" value="子栏目1"></clink>
      <clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
    <link name="主栏目4" value="主栏目4">
      <clink name="子栏目1" value="子栏目1"></clink>
      <clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
    <link name="主栏目5" value="主栏目5">
      <clink name="子栏目1" value="子栏目1"></clink>
      <clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
    <link name="主栏目6" value="主栏目6">
      <clink name="子栏目1" value="子栏目1"></clink>
      <clink name="子栏目2" value="子栏目2"></clink>
      <clink name="子栏目3" value="子栏目3"></clink>
    </link>
	</Navigate>
</configuration>

web.config文件代码