WebService Class

If you don't need access to the common ASP.NET objects, you can still create an XML Web service without deriving from WebService. Additional ASP.NET objects can be accessed through Context.

XML Web service methods that have the OneWay property of either SoapRpcMethodAttribute or SoapDocumentMethodAttribute set to true, do not have access to their HttpContext. As such, accessing any of the properties of the WebService class, from within that XML Web service method, return null.

If you are using the .NET Framework version 1.0 XML Web service methods that have either the SoapRpcMethodAttribute or SoapDocumentMethodAttribute attribute applied to them with the OneWay property of set to true, do not have access to their HttpContext using the static Current property. To access the HttpContext, derive the class implementing the XML Web service method from WebService and access the Context property.

The example below creates an XML Web service, deriving from WebService, in order to use the Context property to obtain the time of the request on the server.

<%@ WebService Language="C#" Class="Util" %>

 using System;
 using System.Web.Services;

 public class Util: WebService {
   [ WebMethod(Description="Returns the time as stored on the Server",
   EnableSession=false)]
   public string Time() {
      return Context.Timestamp.TimeOfDay.ToString();
   }
 }
 

.NET Framework

.NET Framework Client Profile

Windows 8 Consumer Preview, Windows Server 8 Beta, Windows 7, Windows Server 2008 SP2, Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Reference