Preauthenticates a request.
Assembly: System (in System.dll)
static member PreAuthenticate : request:WebRequest * credentials:ICredentials -> Authorization
Return ValueType: System.Net.Authorization
An instance of the Authorization class if the request can be preauthenticated; otherwise, a null reference (Nothing in Visual Basic). If credentials is a null reference (Nothing in Visual Basic), this method returns a null reference (Nothing in Visual Basic).
request is a null reference (Nothing in Visual Basic).
If the authentication module can preauthenticate the request, the method returns an Authentication instance and sends the authorization information to the server preemptively instead of waiting for the resource to issue a challenge. This behavior is outlined in section 3.3 of RFC 2617 (HTTP Authentication: Basic and Digest Access Authentication). Authentication modules that support preauthentication allow clients to improve server efficiency by avoiding extra round trips caused by authentication challenges.
Authorization modules that can preauthenticate requests set the IAuthenticationModule.CanPreAuthenticate property to true.
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.