service: WTS_SESSION_LOGOFF event in SESSION CHANGED

hello

i am trying to capture the user information form the service through the HandlerEx Functions while registering.

i am able to get username and domain name by using WTSQueryInformation () API at WTS_SESSION_LOGON. but when i query at "WTS_SESSION_LOGOFF" nothing comes.

Code:

---

UINT GetUserInfoFromSessionID ( DWORD SessionId, CString & sUserName, CString & sDomainName )
{
        UINT nResult = ERROR_SUCCESS;

        LPTSTR  ppBuffer  = NULL;
        DWORD  pBytesReturned = 0;
        //query domain
        if( WTSQuerySessionInformation( WTS_CURRENT_SERVER_HANDLE,
                                                                        SessionId,
                                                                        WTSDomainName,
                                                                        &ppBuffer,
                                                                        &pBytesReturned ) )
        {
                sDomainName = CString( ppBuffer );
        }
        else
        {
                nResult = GetLastError();
                MLOGERR(_T("Failed to Get DomainName From SessionID Error:%d"),nResult);
        }
        WTSFreeMemory( ppBuffer );
       
        //query UserName

        if( WTSQuerySessionInformation( WTS_CURRENT_SERVER_HANDLE,
                SessionId,
                WTSUserName,
                &ppBuffer,
                &pBytesReturned) )
        {
                sUserName = CString( ppBuffer );
        }
        else
        {
                nResult = GetLastError();
                MLOGERR(_T("Failed to Get UserName From SessionID Error:%d"),nResult);       
        }

        WTSFreeMemory( ppBuffer );

        return nResult;
}

---

the error i got is Error:2 = The system cannot find the file specified.


has any one encountered this before?

regards
deepak

Hm.. perhaps on logoff, the tokeis invalid and domain name and user name doesn't make sense anymore.