<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<sectionGroup type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
<sectionGroup type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
<section type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere" />
<section type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
<section type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication" />
</sectionGroup>
</sectionGroup>
</sectionGroup>
</configSections>
<system.web>
<customErrors defaultRedirect="" />
<trace mostRecent="true" pageOutput="true" />
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</controls>
</pages>
<compilation>
<assemblies>
<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" />
</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 type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</httpModules>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<modules>
<add preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</modules>
<handlers>
<remove />
<add verb="*" path="*.asmx" preCondition="integratedMode"
type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
<add 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 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>
</configuration>
前台页面：
复制代码 代码如下:
<asp:ScriptManager runat="server" EnablePartialRendering="true">
</asp:ScriptManager>
<div>
<asp:UpdatePanel runat="server" UpdateMode="Conditional">
<ContentTemplate>
<table cellpadding="0" cellspacing="2" >
<tr>
<td bgcolor="#EAEAEA" >
请选择省/市/区：
</td>
<td bgcolor="#f7f7f7">
<asp:DropDownList runat="server"
AutoPostBack="true" onselectedindexchanged="dpProvince_SelectedIndexChanged" />
<asp:DropDownList runat="server" AutoPostBack="true"
onselectedindexchanged="dpCity_SelectedIndexChanged" />
<asp:DropDownList runat="server" AutoPostBack="false"
/>
</td>
</tr>
<tr>
<td bgcolor="#EAEAEA" >
</td>
<td bgcolor="#f7f7f7">
<asp:UpdateProgress runat="server">
<ProgressTemplate>
正在查询，请稍候……………………</ProgressTemplate>
</asp:UpdateProgress>
</td>
</tr>
</table>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="dpProvince" EventName="SelectedIndexChanged" />
<asp:AsyncPostBackTrigger ControlID="dpCity" EventName="SelectedIndexChanged" />
</Triggers>
</asp:UpdatePanel>
</div>
Framework 4：与代码完全一样，只是无需在web.config中作配置。
如图：
二、基于JQuery1.4.1的Ajax框架，主要好处是与后续版本的asp.net完全集成。
基于ashx作一个 Request，主要代码：
复制代码 代码如下: