c:\inetpub\wwwroot\wss\virtualdirectories\80
 添加<sectionGroup>元素到 <configSections>标记：<configSections>
      <sectionGroupname="system.web.extensions"type="System.Web.Configuration.SystemWebExtensionsSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35">
     <sectionGroupname="scripting"type="System.Web.Configuration.ScriptingSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35">
         <sectionname="scriptResourceHandler"type="System.Web.Configuration.ScriptingScriptResourceHandlerSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"requirePermission="false"allowDefinition="MachineToApplication"/>
       <sectionGroupname="webServices"type="System.Web.Configuration.ScriptingWebServicesSectionGroup,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35">
         <sectionname="jsonSerialization"type="System.Web.Configuration.ScriptingJsonSerializationSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"requirePermission="false"allowDefinition="Everywhere"/>
         <sectionname="profileService"type="System.Web.Configuration.ScriptingProfileServiceSection,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"requirePermission="false"allowDefinition="MachineToApplication"/>
         <sectionname="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>
</configSections>
添加<controls>节的内容，放在<system.web>/<pages>标记中。    <pages>
     <controls>
       <addtagPrefix="asp"namespace="System.Web.UI"assembly="System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
     </controls>
   </pages>   
在<compilation>标记内的<assemblies>标记中添加下面的内容：      <assemblies>
      <addassembly="System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
     </assemblies>
在<httpHandlers>节中添加下面的内容： <httpHandlers>
     <addverb="*"path="*.asmx"validate="false"type="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
     <addverb="*"path="*_AppService.axd"validate="false"type="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
     <addverb="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>
在HttpModules节中添加下面的注册内容，放在所有已有的注册内容下面  <httpModules>
     <addname="ScriptModule"type="System.Web.Handlers.ScriptModule,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
 </httpModules>
在<SharePoint>/<SafeControls>节中，添加一条SafeControl，用于MicrosoftAjaxExtensions的System.Web.UI命名空间。  <SafeControls>
     <SafeControlAssembly="System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"Namespace="System.Web.UI"TypeName="*"Safe="True"/>
 </SafeControls>
最后,添加下面的configuration标记到web.config文件末尾,在结束标记<configuration>前面。
 <system.web.extensions>
   <scripting>
     <webServices>
     <!--Uncommentthislinetoenabletheauthenticationservice.IncluderequireSSL="true"ifappropriate.-->
     <!--
       <authenticationServiceenabled="true"requireSSL="true|false"/>
     -->
     <!--Uncommenttheselinestoenabletheprofileservice.ToallowprofilepropertiestoberetrievedandmodifiedinASP.NETAJAXapplications,youneedtoaddeachpropertynametothereadAccessPropertiesandwriteAccessPropertiesattributes.-->
     <!--
     <profileServiceenabled="true"
                     readAccessProperties="propertyname1,propertyname2"
                     writeAccessProperties="propertyname1,propertyname2"/>
     -->
     </webServices>
     <!--
     <scriptResourceHandlerenableCompression="true"enableCaching="true"/>
     -->
   </scripting>
 </system.web.extensions>
 <system.webServer>
   <validationvalidateIntegratedModeConfiguration="false"/>
   <modules>
     <addname="ScriptModule"preCondition="integratedMode"type="System.Web.Handlers.ScriptModule,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
   </modules>
   <handlers>
     <removename="WebServiceHandlerFactory-Integrated"/>
     <addname="ScriptHandlerFactory"verb="*"path="*.asmx"preCondition="integratedMode"
          type="System.Web.Script.Services.ScriptHandlerFactory,System.Web.Extensions,Version=1.0.61025.0,Culture=neutral,PublicKeyToken=31bf3856ad364e35"/>
     <addname="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"/>
     <addname="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>
利用AjaxBaseWebPart进行开发

编写使用该扩展的WebPart最简单的办法就是直接继承别人写好的AjaxBaseWebPart。下面是我用的一个。您也可以用其他的，或自己写一个。
下面是命名空间引用部分：
　usingSystem;
usingSystem.Collections.Generic;
usingSystem.Text;
usingSystem.Web;
usingSystem.Web.UI.WebControls.WebParts;
usingSystem.Xml.Serialization;
usingSystem.Web.UI;
usingMicrosoft.SharePoint.WebPartPages;
usingMicrosoft.SharePoint.Utilities;
usingSystem.Web.UI.WebControls;
usingSystem.Drawing;
下面是AjaxBaseWebPart类的实现部分：
　    ///<summary>
   ///AbaseclassthatimplementsallthefunctionalityrequiredtouseASP.netAjaxextensionsinsideWSS
   ///</summary>
   [XmlRoot(Namespace="Deps.AjaxBaseWebpart")]
   publicabstractclassAjaxBaseWebpart:Microsoft.SharePoint.WebPartPages.WebPart
   {
       /*
        *TheideaandthecodebehindthisbasewebpartwastakenfromEricsblogpostat:
        *
        *ThisbasicallymanagesthepresenceandconfigurationoftheScriptManager
        *whichisrequiredbyASP.netajaxextensionstohandlepostbacks,ect.Thiswebpartalsoincludes
        *acommonmethodforhandlingerrors.
        */
       #regionDeclarations
       privatestring_ValidationGroupId;
       privateValidationSummary_ErrorContainer;
       privateScriptManager_AjaxManager;
       #endregion

#regionConstructor
       publicAjaxBaseWebpart()
       {

}
       #endregion

#regionMethods
       ///<summary>
       ///Usedtoprovideacommonwaytodisplayerrorstotheuserofthecurrentwebpart.
       ///</summary>
       ///<paramname="message">Descriptionoftheerrorthatoccured.</param>
       publicvoidRegisterError(stringmessage)
       {
           if(this.Controls.Contains(_ErrorContainer))
           {
               //thiswayofgeneratingauniquecontrolidisusedinsomeoftheOOBwebparts
               intuniqueCounter;
               if(HttpContext.Current.Items["GetUniqueControlId"]!=null)
               {
                   uniqueCounter=(int)HttpContext.Current.Items["GetUniqueControlId"];
               }
               else
               {
                   uniqueCounter=0;
               }
               uniqueCounter++;
               HttpContext.Current.Items["GetUniqueControlId"]=uniqueCounter;

//createacustomvalidatortoregisterthecurrenterrormessagewiththeValidationSummarycontrol
               CustomValidatorcv=newCustomValidator();
               cv.ID=string.Concat("_Error_",uniqueCounter);
               cv.ValidationGroup=_ValidationGroupId;
               cv.Display=ValidatorDisplay.None;
               cv.IsValid=false;
               cv.ErrorMessage=message;

this.Controls.Add(cv);
           }
           else
           {
               //ifRegisterErroriscalledbeforetheCreateChildControlsoverrideinAjaxBasePartthentransfertheusertoanerrorpageusingtheSPUtility
               SPUtility.TransferToErrorPage("TheCreateChildControlsfunctionoftheAjaxBaseParthasnotbeencalled. Youprobablyneedtoadd\"base.CreateChildControls()\"tothetopofyourCreateChildControlsoverride.");
           }
       }
       ///<summary>
       ///NeedstobecalledtoensurethattheValidationSummarycontrolisregisteredonthepage. Anychildwebpartswillneedtohavebase.CreateChildControls()atthetopoftheirownCreateChildControlsoverride.
       ///</summary>
       protectedoverridevoidCreateChildControls()
       {
           base.CreateChildControls();

if(!this.Controls.Contains(_ErrorContainer))
           {
               _ValidationGroupId=Guid.NewGuid().ToString();

_ErrorContainer=newValidationSummary();
               _ErrorContainer.ID="_ErrorContainer";
               _ErrorContainer.ValidationGroup=_ValidationGroupId;
               _ErrorContainer.BorderStyle=BorderStyle.Solid;
               _ErrorContainer.BorderWidth=Unit.Pixel(3);
               _ErrorContainer.BorderColor=Color.Red;

this.Controls.Add(_ErrorContainer);
           }
       }
       #endregion

#regionEvents
       ///<summary>
       ///Oninitfiresbeforepageload.ModificationstothepagethatarenecessarytosupportAjaxaredonehere.
       ///</summary>
       protectedoverridevoidOnInit(EventArgse)
       {
           base.OnInit(e);

//gettheexistingScriptManagerifitexistsonthepage
           _AjaxManager=ScriptManager.GetCurrent(this.Page);

if(_AjaxManager==null)
           {
               //createnewScriptManagerandEnablePartialRendering
               _AjaxManager=newScriptManager();
               _AjaxManager.EnablePartialRendering=true;

//Fixproblemwithpostbacksandformactions(DevDiv55525)
               Page.ClientScript.RegisterStartupScript(typeof(AjaxBaseWebpart),this.ID,"_spOriginalFormAction=document.forms[0].action;",true);

//tag:"form"att:"onsubmit"val:"return_spFormOnSubmitWrapper()"blocksasyncpostbacksafterthefirstone
               //notcalling"_spFormOnSubmitWrapper()"breaksallpostbacks