API得到Windows版本

/**
 * Windows Version
 *   https://msdn.microsoft.com/en-us/library/windows/desktop/dn481241(v=vs.85).aspx

 * In Windows 8.1 and Windows 10, the GetVersion and GetVersionEx functions have been deprecated.
 * In Windows 10, the VerifyVersionInfo function has also been deprecated.

 * Operating system Version number (Major.Minor)
 *
 *     Windows 10             6.4, 7.x, 10.0
 *     Windows 8.1            6.3
 *     Windows 8              6.2
 *     Windows 7              6.1
 *     Windows Server 2008 R2 6.1
 *     Windows Server 2008    6.0
 *     Windows Vista          6.0
 *     Windows Server 2003 R2 5.2
 *     Windows Server 2003    5.2
 *     Windows XP             5.1
 *     Windows 2000           5.0
 *     Windows NT40           4.0
 *     Windows NT35           3.0
 */
typedef enum OSWindowsVersion {
    OS_UNKNOWN  = 0,
    OS_WINNT35  = 35,
    OS_WINNT40  = 40,
    OS_WIN2000  = 50,
    OS_WINXP    = 51,
    OS_WIN2003	= 52,
    OS_WINXP64	= 52,
    OS_Vista    = 60,
    OS_WIN7     = 61,
    OS_WIN8     = 62,
    OS_WIN2012  = 62,
    OS_WIN8_1   = 63,
    OS_WIN10   = 100
} OSWindowsVersion;

OSWindowsVersion GetWindowsVersion();

// Author: cheungmine
// 20161205

BOOL GetNtdllVersion(DWORD *dwMajorVer, DWORD *dwMinorVer, DWORD *dwBuildNum)
{
    typedef void (WINAPI *PFN_RTLGETNTVERSIONNUMBERS)(DWORD*, DWORD*, DWORD*);

    HMODULE hNtdll = LoadLibrary("ntdll.dll");

    if (hNtdll) {
        PFN_RTLGETNTVERSIONNUMBERS pfnGetWinVer = (PFN_RTLGETNTVERSIONNUMBERS)
            GetProcAddress(hNtdll, "RtlGetNtVersionNumbers");

        if (pfnGetWinVer) {
            pfnGetWinVer(dwMajorVer, dwMinorVer, dwBuildNum);
            FreeLibrary(hNtdll);
            return TRUE;
        }

        FreeLibrary(hNtdll);
    }

    return FALSE;
}

OSWindowsVersion GetWindowsVersion()
{
    DWORD majorVer = 0;
    DWORD minorVer = 0;
    DWORD buildNum = 0;
    BOOL isNtVer = 0;

    OSVERSIONINFO info;
    OSWindowsVersion osVer = OS_UNKNOWN;

    SeZero(&info, sizeof(info));
    info.dwOSVersionInfoSize = sizeof(info);

    if (GetVersionEx(&info) && info.dwPlatformId == VER_PLATFORM_WIN32_NT) {
        switch (info.dwMajorVersion) {
        case 3:
            osVer = OS_WINNT35;
            break;

        case 4:
            osVer = OS_WINNT40;
            break;

        case 5:
            if (info.dwMinorVersion == 0) {
                osVer = OS_WIN2000;
            } else if (info.dwMinorVersion == 1) {
                osVer = OS_WINXP;
            } else if (info.dwMinorVersion >= 2) {
                osVer = OS_WIN2003;
            }
            break;

        case 6:
            if (info.dwMinorVersion == 0) {
                osVer = OS_Vista;
            } else if (info.dwMinorVersion == 1) {
                osVer = OS_WIN7;
            } else if (info.dwMinorVersion == 2) {
                // 8 or 8.1 or 10
                osVer = OS_WIN8;

                if (GetNtdllVersion(&majorVer, &minorVer, &buildNum)) {
                    if (majorVer == 6) {
                        if (minorVer == 3) {
                            osVer = OS_WIN8_1;
                        } else if (minorVer >= 4) {
                            osVer = OS_WIN10;
                        }
                    } else if (majorVer >= 7) {
                        osVer = OS_WIN10;
                    }
                }
            } else if (info.dwMinorVersion == 3) {
                osVer = OS_WIN8_1;
            } else if (info.dwMinorVersion >= 4) {
                osVer = OS_WIN10;
            }
            break;

        default:
            if (info.dwMajorVersion >= 7) {
                osVer = OS_WIN10;
            }
            break;
        }
    } else if (GetNtdllVersion(&majorVer, &minorVer, &buildNum)) {
        // should not run to this!!
        switch (majorVer) {
        case 3:
            osVer = OS_WINNT35;
            break;

        case 4:
            osVer = OS_WINNT40;
            break;

        case 5:
            if (minorVer == 0) {
                osVer = OS_WIN2000;
            } else if (minorVer == 1) {
                osVer = OS_WINXP;
            } else if (minorVer >= 2) {
                osVer = OS_WIN2003;
            }
            break;

        case 6:
            if (minorVer == 0) {
                osVer = OS_Vista;
            } else if (minorVer == 1) {
                osVer = OS_WIN7;
            } else if (minorVer == 2) {
                osVer = OS_WIN8;
            } else if (minorVer == 3) {
                osVer = OS_WIN8_1;
            } else if (minorVer >= 4) {
                osVer = OS_WIN10;
            }
            break;

        default:
            if (majorVer >= 7) {
                osVer = OS_WIN10;
            }
            break;
        }
    }

    return osVer;
}