Use the WebMethodAttribute to mark all the methods
that should be made available to web service clients. All methods
marked with this attribute will be accessible automatically and will
be included in the WSDL document (and the proxy class) that .NET
generates. Methods that are not marked with this attribute will not
visible or usable, even if they are public.
You can set various properties when you use this attribute. For
example, the Description property contains a
string of information about a web method and is used for
automatically generated description documents and the Internet
Explorer test page. CacheDuration specifies (in
seconds) how long a response will be cached and reused for web method
requests with identical parameter values.
EnableSession allows you to configure whether
session support is enabled for your web method. By default, a web
service method will not be cached at all, and session support will
not be enabled. The BufferResponse property is
rarely used, as it only applies to HTTP requests. By default,
BufferResponse is True, as
responses are serialized to memory and transferred only when
complete. This ensures best performance for small amounts of data.
Note that if you disable response buffering, you will not be able to
use the method in conjunction with a custom SOAP extension.
The MessageName property is used to add an alias
to a method. This property is most commonly used with polymorphic
(overloaded) methods, which must be given unique names, or
"disambiguated," before you can use
them as web methods. When adding overloaded methods, the original
method should retain its name for compatibility with existing
clients.
The TransactionOption property allows a web method
to take part in a COM+ transaction. Due to the stateless nature of
the HTTP protocol, web service methods can only participate as the
root object in a transaction. This means that both
System.EnterpriseServices.TransactionOption.RequiresNew
and
System.EnterpriseServices.TransactionOption.Required
will have the same effect, causing the web method to start a new
transaction when it is invoked. Other COM objects that require
transactions can then be created and used by the web method. A
transaction started in this way is committed automatically when the
method ends, unless the method explicitly calls
System.EnterpriseServices.ContextUtil.SetAbort( )
or an unhandled exception occurs.
To set a property of the WebMethodAttribute,
specify it by name in the attribute declaration (as in
[WebMethod(EnableSession = True)])
public sealed class WebMethodAttribute : Attribute {
// Public Constructors
public
WebMethodAttribute ( );
public
WebMethodAttribute (bool
enableSession );
public
WebMethodAttribute (bool
enableSession , System.EnterpriseServices.TransactionOption
transactionOption );
public
WebMethodAttribute (bool
enableSession , System.EnterpriseServices.TransactionOption
transactionOption ,
int
cacheDuration );
public
WebMethodAttribute (bool
enableSession , System.EnterpriseServices.TransactionOption
transactionOption ,
int
cacheDuration , bool
bufferResponse );
// Public Instance Properties
public bool
BufferResponse {set; get; }
public int
CacheDuration {set; get; }
public string
Description {set; get; }
public bool
EnableSession {set; get; }
public string
MessageName {set; get; }
public TransactionOption
TransactionOption {set; get; }
}