DefaultAuthenticationEventArgs Constructor (HttpContext)

 

Initializes a new instance of the DefaultAuthenticationEventArgs class.

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

public DefaultAuthenticationEventArgs(
	HttpContext context
)

Parameters

context
Type: System.Web.HttpContext

The context for the event.

The DefaultAuthenticationModule object constructs a DefaultAuthenticationEventArgs object using the current HttpContext and passes it to the DefaultAuthentication_OnAuthenticate event.

You can use the Context property of the DefaultAuthenticationEventArgs object supplied to the DefaultAuthentication_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 of the HttpContext referenced by the Context property, the DefaultAuthenticationModule sets the User property of the HttpContext to a GenericPrincipal object that contains no user information.

The DefaultAuthentication_OnAuthenticate event is raised after the AuthenticateRequest event and before the AuthorizeRequest event. If you have an section that depends on the user name to deny or allow access to your application, modifying the User property of the current HttpContext can affect the behavior of your application. Be sure that the user name you set during the DefaultAuthentication_OnAuthenticate event is considered when you specify the section in your configuration.

The following code example uses the DefaultAuthentication_OnAuthenticate event to test whether the User property of the current HttpContext is null. If the property is null, the example sets the User property of the current HttpContext to a GenericPrincipal object where the Identity property of the GenericPrincipal object is a GenericIdentity object with a Name property value of "default".

System_CAPS_noteNote

The DefaultAuthentication_OnAuthenticate event is raised before the AuthorizeRequest event. As a result, if you set the User property of the current HttpContext to a custom identity, it can affect the behavior of your application. For example, if you are using the FormsAuthentication class and you are ensuring that only authenticated users have access to your site, by using the section and specifying <deny users="?" />, you will cause the element in this example to be ignored, as the user will have a name, which is "default". Instead you would specify <deny users="default" /> to ensure that only authenticated users can access your site.

public void DefaultAuthentication_OnAuthenticate(object sender,
                                                 DefaultAuthenticationEventArgs args)
{
  if (args.Context.User == null)
    args.Context.User = 
      new System.Security.Principal.GenericPrincipal(
        new System.Security.Principal.GenericIdentity("default"),
        new String[0]);
}

.NET Framework
Available since 1.1
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