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 nullNothingnullptra null reference (Nothing in Visual Basic).

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="VB" Class="Util" %>

Imports System
Imports System.Web.Services

Public Class Util
    Inherits WebService

    <WebMethod(Description := "Returns the time as stored on the Server", _
        EnableSession := False)> _
    Public Function Time() As String

        Return Context.Timestamp.TimeOfDay.ToString()
    End Function
End Class

<%@ 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();
   }
 }

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

.NET Framework

Reference