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WebMethodAttribute Constructor (Boolean, TransactionOption, Int32)

Initializes a new instance of the WebMethodAttribute class.

Namespace:  System.Web.Services
Assembly:  System.Web.Services (in System.Web.Services.dll)

public WebMethodAttribute(
	bool enableSession,
	TransactionOption transactionOption,
	int cacheDuration


Type: System.Boolean
Initializes whether session state is enabled for the XML Web service method.
Type: System.EnterpriseServices.TransactionOption
Initializes the transaction support of an XML Web service method.
Type: System.Int32
Initializes the number of seconds the response is cached.

A web service call can only be the root of a transaction, due to the stateless nature of the HTTP protocol. This means that the following two settings are equivalent, with each call creating a new transaction:

[WebMethod(TransactionOption = TransactionOption.Required)]
[WebMethod(TransactionOption = TransactionOption.RequiresNew)]

It also means that all the following settings are equivalent; meaning no transaction support:

[WebMethod] // TransactionOption.Disabled is the default
[WebMethod(TransactionOption = TransactionOption.Disabled)]
[WebMethod(TransactionOption = Transaction.NotSupported)]
[WebMethod(TransactionOption = Transaction.Supported)]

<%@ WebService Language="C#" Class="Counter" %>
<%@ assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %>

using System.Web.Services;
using System;
using System.Web;
using System.EnterpriseServices;

public class Counter : WebService {

     [ WebMethod(true,TransactionOption.NotSupported,60) ]
     public int ServiceUsage() {
          // If the XML Web service has not been accessed, initialize it to 1.
          if (Application["MyServiceUsage"] == null) {
              Application["MyServiceUsage"] = 1;
          else {
              // Increment the usage count.
              Application["MyServiceUsage"] = ((int) Application["MyServiceUsage"]) + 1;

          // Return the usage count.     
          return  (int) Application["MyServiceUsage"];

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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