Question

I am trying to use the function WTSQuerySessionInformation in a Visual C# project, including the following lines in the class definition:

[DllImport("Wtsapi32.dll")]
        static extern bool WTSQuerySessionInformation(
            System.IntPtr hServer, int sessionId, WTS_INFO_CLASS wtsInfoClass, out System.IntPtr ppBuffer, out uint pBytesReturned); private Boolean remote_connected = false;

I get an error saying:

Error: he type or namespace name 'WTS_INFO_CLASS' could not be found (are you missing a using directive or an assembly reference?)

Can anyone please let me know what needs to be done in the project to fix this error?

Answer 1

You are nearly there:

enum WTS_INFO_CLASS
{
     WTSInitialProgram,
     WTSApplicationName,
     WTSWorkingDirectory,
     WTSOEMId,
     WTSSessionId,
     WTSUserName,
     WTSWinStationName,
     WTSDomainName,
     WTSConnectState,
     WTSClientBuildNumber,
     WTSClientName,
     WTSClientDirectory,
     WTSClientProductId,
     WTSClientHardwareId,
     WTSClientAddress,
     WTSClientDisplay,
     WTSClientProtocolType,
     WTSIdleTime,
     WTSLogonTime,
     WTSIncomingBytes,
     WTSOutgoingBytes,
     WTSIncomingFrames,
     WTSOutgoingFrames,
     WTSClientInfo,
     WTSSessionInfo
};

[DllImport("Wtsapi32.dll", SetLastError=true)]
static extern bool WTSQuerySessionInformation(
    IntPtr hServer, 
    uint sessionId, 
    WTS_INFO_CLASS wtsInfoClass, 
    out IntPtr ppBuffer, 
    out uint pBytesReturned
);

Note that sessionId is a DWORD which is an untyped 32 bit integer.