pinvoke.net: Edit: advapi32.ImpersonateLoggedOnUser

@msdn=http://search.microsoft.com/search/results.aspx?qu=$$$
@pinvoke=http://pinvoke.net/$$$.htm
@impersonatemethoddoc=http://msdn2.microsoft.com/en-us/library/system.security.principal.windowsidentity.impersonate.aspx

Summary: Lets the calling thread impersonate the security context of a logged-on user. The user is represented by a token handle.

!!!!C# Signature:
 [DllImport("advapi32.dll", SetLastError=true)]
 static extern bool ImpersonateLoggedOnUser(IntPtr hToken);
!!!!VB Signature:
 Declare Function ImpersonateLoggedOnUser Lib "advapi32.dll" (ByVal hToken As Integer) As Integer
!!!!User-Defined Types:
None.

!!!!Notes:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/secauthz/security/impersonateloggedonuser.asp

!!!!Tips & Tricks:
Don't forget to call RevertToSelf when done.
The last param in LogonUser (phToken) can be declared as Integer to work with the following VB.Net sample. The key is making sure it is ByRef vs ByVal.

!!!!Sample Code:
 Public Sub Logon(ByVal strUser As String, ByVal strPassword As String, ByVal strDomain As String)
        Dim lngLogonType, lngLogonProvider, lngTokenHandle As Integer
        Dim blnResult As Boolean

lngLogonType = LOGON32_LOGON_INTERACTIVE
        lngLogonProvider = LOGON32_PROVIDER_DEFAULT

blnResult = RevertToSelf()

blnResult = LogonUser(strUser, strDomain, strPassword, _
                                             lngLogonType, lngLogonProvider, _
                                             lngTokenHandle)
        If blnResult Then
            blnResult = ImpersonateLoggedOnUser(lngTokenHandle)
            CloseHandle(lngTokenHandle)
        Else
            MsgBox("Error logging on")
        End If
 End Sub

!!!!Alternative Managed API:
WindowsIdentity.Impersonate@impersonatemethoddoc

Documentation: ImpersonateLoggedOnUser@msdn on MSDN