The WebServiceAttribute is not required for an XML Web service to be published and executed. You can use the WebServiceAttribute to specify a name for the XML Web service that is not restricted by the rules for a common language runtime identifier, which is used in the service description and the Service help page for the XML Web service.

An XML Web service should change its default XML namespace before it is made public. Each XML Web service needs a unique XML namespace to identify it so that client applications can distinguish it from other services on the Web. http://tempuri.org/ is available for XML Web services that are under development, but published XML Web services should use a more permanent namespace.

Your XML Web service should be identified by a XML namespace that you control. For example, you could use your company's Internet domain name as part of the XML namespace. Although many XML Web service XML namespaces look like URLs, they need not point to an actual resource on the Web. (XML Web service XML namespaces are URIs.) For XML Web services created using ASP.NET, the default XML namespace can be changed using Namespace property.

For more information about using attributes, see Extending Metadata Using Attributes.

The following example sets the Description property of the WebServiceAttribute to " Common Server Variables " and sets the XML namespace to http://www.microsoft.com/.

<%@ WebService Language="VB" Class= "ServerVariables"%>

Imports System
Imports System.Web.Services

<WebService(Description := "Common Server Variables", _
 Namespace := "http://www.contoso.com/")> _
Public Class ServerVariables
    Inherits WebService 

    <WebMethod(Description := "Obtains the Computer Machine Name", _
        EnableSession := False)> _
    Public Function GetMachineName() As String

        Return Server.MachineName
    End Function
End Class

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

 using System;
 using System.Web.Services;

 [ WebService(Description="Common Server Variables",Namespace="http://www.contoso.com/")]
 public class ServerVariables: WebService {


    [ WebMethod(Description="Obtains the Server Computer Name",EnableSession=false)]
    public string GetMachineName() {
       return Server.MachineName;
    }   
 }

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