WebMethodAttribute Class (System.Web.Services)

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.NET Framework Class Library

WebMethodAttribute Class

Adding this attribute to a method within an XML Web service created using ASP.NET makes the method callable from remote Web clients. This class cannot be inherited.

Inheritance Hierarchy

System.Object
System.Attribute
System.Web.Services.WebMethodAttribute

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

Syntax

Visual Basic

<AttributeUsageAttribute(AttributeTargets.Method)> _
Public NotInheritable Class WebMethodAttribute _
	Inherits Attribute

[AttributeUsageAttribute(AttributeTargets.Method)]
public sealed class WebMethodAttribute : Attribute

Visual C++

[AttributeUsageAttribute(AttributeTargets::Method)]
public ref class WebMethodAttribute sealed : public Attribute

[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Method)>]
type WebMethodAttribute =  
    class
        inherit Attribute
    end

The WebMethodAttribute type exposes the following members.

Constructors

	Name	Description
	WebMethodAttribute	Initializes a new instance of the WebMethodAttribute class.
	WebMethodAttribute(Boolean)	Initializes a new instance of the WebMethodAttribute class.
	WebMethodAttribute(Boolean, TransactionOption)	Initializes a new instance of the WebMethodAttribute class.
	WebMethodAttribute(Boolean, TransactionOption, Int32)	Initializes a new instance of the WebMethodAttribute class.
	WebMethodAttribute(Boolean, TransactionOption, Int32, Boolean)	Initializes a new instance of the WebMethodAttribute class.

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Properties

	Name	Description
	BufferResponse	Gets or sets whether the response for this request is buffered.
	CacheDuration	Gets or sets the number of seconds the response should be held in the cache.
	Description	A descriptive message describing the XML Web service method.
	EnableSession	Indicates whether session state is enabled for an XML Web service method.
	MessageName	The name used for the XML Web service method in the data passed to and returned from an XML Web service method.
	TransactionOption	Indicates the transaction support of an XML Web service method.
	TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)

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Methods

	Name	Description
	Equals	Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Returns the hash code for this instance. (Inherited from Attribute.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IsDefaultAttribute	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
	Match	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Explicit Interface Implementations

	Name	Description
	_Attribute.GetIDsOfNames	Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
	_Attribute.GetTypeInfo	Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
	_Attribute.GetTypeInfoCount	Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
	_Attribute.Invoke	Provides access to properties and methods exposed by an object. (Inherited from Attribute.)

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Remarks

Methods within a class that have this attribute set are called XML Web service methods. The method and class must be public and running inside an ASP.NET Web application.

Topic	Location
Walkthrough: Creating and Using an ASP.NET Web Service in Visual Web Developer	Building ASP .NET Web Applications in Visual Studio

Examples

In the example below the method GetMachineName can be remotely called across the Web, because it has a WebMethodAttribute. GetUserName cannot be called remotely, because it does not have a WebMethodAttribute, even though it is public.

Visual Basic


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

Imports System
Imports System.Web.Services

Public Class Util
    Inherits WebService

    Public Function GetUserName() As String
        Return User.Identity.Name
    End Function    

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

        Return Server.MachineName
    End Function
End Class


<%@ WebService Language="C#" Class="Util"%>
    using System;
    using System.Web.Services;
    public class Util: WebService {
       public string GetUserName() {
          return User.Identity.Name;
       }

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

Version Information

.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

Platforms

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.

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Reference

System.Web.Services Namespace

TransactionOption

WebService