System.Web.Security Namespace

Represents the method that will handle the Authenticate event of a FormsAuthenticationModule.

[ VB ]
Public Delegate Sub FormsAuthenticationEventHandler ( _
   sender As Object, _
   e As FormsAuthenticationEventArgs _
)

[ C# ]
Public delegate void FormsAuthenticationEventHandler (
   object sender,
   FormsAuthenticationEventArgs e
);

[ C++ ]
Public __gc __delegate void FormsAuthenticationEventHandler (
   Object* sender,
   FormsAuthenticationEventArgs* e
);

In [ JScript ], you can use the delegates in the .NET Framework, but you cannot define your own.

The declaration of your event handler must have the same parameters as the FormsAuthenticationEventHandler delegate declaration.

sender

The source of the event.

e

A FormsAuthenticationEventArgs that contains the event data.

The FormsAuthenticationEventHandler delegate is defined for the Authenticate event of the FormsAuthenticationModule class.

You can handle the Authenticate event of the FormsAuthenticationModule class by specifying a subroutine named FormsAuthentication_OnAuthenticate in the Global.asax file for your ASP.NET application. The Authenticate event is raised during the AuthenticateRequest event.

The FormsAuthenticationModule constructs a FormsAuthenticationEventArgs object using the current HttpContext and passes it to the FormsAuthentication_OnAuthenticate event.

You can use the User property of the FormsAuthenticationEventArgs object supplied to the FormsAuthentication_OnAuthenticate event to set the User property of the current HttpContext to a custom IPrincipal object.

If you do not specify a value for the User property during the FormsAuthentication_OnAuthenticate event, the identity supplied by the forms authentication ticket in the cookie or URL is used.

The FormsAuthentication_OnAuthenticate event is only raised when the authentication Mode is set to Forms and the FormsAuthenticationModule is an active HTTP module for the application.

The following code example uses the FormsAuthentication_OnAuthenticate event to set the User property of the current HttpContext to a GenericPrincipal object with a custom Identity.

public void FormsAuthentication_OnAuthenticate ( object src, FormsAuthenticationEventArgs args ) {
   if ( FormsAuthentication.CookiesSupported ) {
      if ( Request.Cookies[FormsAuthentication.FormsCookieName] != null ) {
         try {
            FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt (
               Request.Cookies [ FormsAuthentication.FormsCookieName ].Value );
            args.User = new System.Security.Principal.GenericPrincipal (
               new Samples.AspNet.Security.MyFormsIdentity ( ticket ), new string [ 0 ] );
         }
         catch ( Exception e ) {
            // Decrypt method failed.
         }
      }
   } else {
      throw new HttpException ( "Cookieless Forms Authentication is not " +
         "supported for this application." );
   }
}

Public Sub FormsAuthentication_OnAuthenticate ( src As Object, args As FormsAuthenticationEventArgs )
   If FormsAuthentication.CookiesSupported Then
      If Not Request.Cookies ( FormsAuthentication.FormsCookieName ) Is Nothing Then
         Try
            Dim ticket As FormsAuthenticationTicket = FormsAuthentication.Decrypt ( _
               Request.Cookies ( FormsAuthentication.FormsCookieName ) .Value )
            args.User = New System.Security.Principal.GenericPrincipal ( _
               New Samples.AspNet.Security.MyFormsIdentity ( ticket ), New String ( 0 ) { } )

         Catch e As HttpException
            ' Decrypt method failed.
         End Try
      End If
   Else
      Throw New Exception ( "Cookieless Forms Authentication is not " & _
         "supported for this application." )
   End If
End Sub

FormsAuthenticationModule   FormsAuthenticationEventArgs