ScriptManager ServiceReference in SharePoint

Question

I have always used jQuery.ajax to retrieve data from listdata.svc or lists.asmx in SharePoint and from some custom web services. Now I will try Microsoft Ajax Library and especially ServiceReference in ASP.NET which can be added to ScriptManager. Then javascript proxy should be created automatically.

Here is my ServiceReference in the masterpage:

<asp:ScriptManager id="ScriptManager" runat="server" 
  EnablePageMethods="false" 
    EnablePartialRendering="true" 
  EnableScriptGlobalization="false" 
    EnableScriptLocalization="true">
    <Services>
        <asp:ServiceReference Path="/_vti_bin/lists.asmx" />
    </Services>
</asp:ScriptManager>

When I try this I get the 401 error:

GET http://dev/_vti_bin/lists.asmx/jsdebug 401 (Unauthorized)

Has anyone tried ServiceReference in SharePoint?

EDIT (2012-02-20): I want to call a custom wcf like Wictor Wilén. It works very well with jquery ajax. My custom.svc file is:

<%@ ServiceHost 
    Debug="true" 
    Language="C#" 
    Service="Takana.WCFService,Takana, Version=1.0.0.0, Culture=neutral, PublicKeyToken=0c0327f8b01d9792" 
    Factory="Microsoft.SharePoint.Client.ServerRuntime, Version=14.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>

I tried to replace with a simple .NET example, with no success:

<%@ ServiceHost 
    Debug="true" 
    Language="C#" 
    Service="Takana.WCFService" 
    Factory="System.ServiceModel.Activation.WebScriptServiceHostFactory" %>

Answer 1

The service needs to be AJAX enabled to generate a javascript proxy for you. Lists.asmx is not AJAX enabled.

[WebServiceBinding(ConformsTo=WsiProfiles.BasicProfile1_1), WebService(Namespace="http://schemas.microsoft.com/sharepoint/soap/")]
public class Lists : GenericService, ISoapServiceLists, ISoapServiceListData, ISoapServiceListSchema, IListSoapServiceContentTypes
{
}

For more information see Understanding ASP.NET AJAX Web Services

Answer 2

Dare i ask why you wouldn't just use SPServices (created by @sympmarc), an open source jQuery plugin that wraps methods in the OOTB SharePoint Web / WCF Services, making the use of these services in JavaScript as simple as the following example:

$(document).ready(function() {
  $().SPServices({
    operation: "GetListItems",
    async: false,
    listName: "Announcements",
    CAMLViewFields: "<ViewFields><FieldRef Name='Title' /></ViewFields>",
    completefunc: function (xData, Status) {
      $(xData.responseXML).SPFilterNode("z:row").each(function() {
        var liHtml = "<li>" + $(this).attr("ows_Title") + "</li>";
        $("#tasksUL").append(liHtml);
      });
    }
  });
});