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FormsAuthenticationEventHandler Delegate

Represents the method that handles the FormsAuthentication_OnAuthenticate event of a FormsAuthenticationModule.

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

'Declaration
Public Delegate Sub FormsAuthenticationEventHandler ( _
	sender As Object, _
	e As FormsAuthenticationEventArgs _
)
'Usage
Dim instance As New FormsAuthenticationEventHandler(AddressOf HandlerMethod)

Parameters

sender
Type: System.Object

The source of the event.

e
Type: System.Web.Security.FormsAuthenticationEventArgs

A FormsAuthenticationEventArgs that contains the event data.

The FormsAuthenticationEventHandler delegate is defined for the Authenticate event of the FormsAuthenticationModule class. You can access 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 Sub FormsAuthentication_OnAuthenticate(sender 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

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

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

.NET Framework

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