C++: check if computer is locked

Question

I\'m trying to figure out whether the computer is locked.

I\'ve looked at LockWorkStation function, but the function that I\'m hoping to find is IsWorkStation

Answer 1

Alex Vershynin's version works well, with a few code changes that I had to make.

I had to: change DW_WTSSessionInfoEx to WTSSessionInfoEx (Answering user586399), define "g_dwSessionID" to WTSGetActiveConsoleSessionId(), include Wtsapi32.h. I think that's it ...

Since I can't comment, I'll paste the whole code here.

#include "Wtsapi32.h"
bool IsSessionLocked()
{
    typedef BOOL( PASCAL * WTSQuerySessionInformation )( HANDLE hServer, DWORD SessionId, WTS_INFO_CLASS WTSInfoClass, LPTSTR* ppBuffer, DWORD* pBytesReturned );
    typedef void ( PASCAL * WTSFreeMemory )( PVOID pMemory );

    WTSINFOEXW * pInfo = NULL;
    WTS_INFO_CLASS wtsic = WTSSessionInfoEx;
    bool bRet = false;
    LPTSTR ppBuffer = NULL;
    DWORD dwBytesReturned = 0;
    LONG dwFlags = 0;
    WTSQuerySessionInformation pWTSQuerySessionInformation = NULL;
    WTSFreeMemory pWTSFreeMemory = NULL;

    HMODULE hLib = LoadLibrary( "wtsapi32.dll" );
    if( !hLib )
    {
        return false;
    }
    pWTSQuerySessionInformation = (WTSQuerySessionInformation) GetProcAddress( hLib, "WTSQuerySessionInformationW" );
    if( pWTSQuerySessionInformation )
    {
        pWTSFreeMemory = (WTSFreeMemory) GetProcAddress( hLib, "WTSFreeMemory" );
        if( pWTSFreeMemory != NULL )
        {
            DWORD dwSessionID = WTSGetActiveConsoleSessionId();
            if( pWTSQuerySessionInformation( WTS_CURRENT_SERVER_HANDLE, dwSessionID, wtsic, &ppBuffer, &dwBytesReturned ) )
            {
                if( dwBytesReturned > 0 )
                {
                    pInfo = (WTSINFOEXW*) ppBuffer;
                    if( pInfo->Level == 1 )
                    {
                        dwFlags = pInfo->Data.WTSInfoExLevel1.SessionFlags;
                    }
                    if( dwFlags == WTS_SESSIONSTATE_LOCK )
                    {
                        bRet = true;
                    }
                }
                pWTSFreeMemory( ppBuffer );
                ppBuffer = NULL;
            }
        }
    }
    if( hLib != NULL )
    {
        FreeLibrary( hLib );
    }
    return bRet;
}