C# Window Service Don't change the variables value

Question

I'm trying to make a small service which check whether windows on Remote desktop session or not and open a program if yes

public partial class Service1 : ServiceBase
{
    [DllImport("user32.dll")]
    static extern int GetSystemMetrics(SystemMetric smIndex);
    public enum SystemMetric
    {
        SM_CXSCREEN = 0,  // 0x00
        SM_CYSCREEN = 1,  // 0x01
        SM_CXVSCROLL = 2,  // 0x02
        SM_CYHSCROLL = 3,  // 0x03
        SM_CYCAPTION = 4,  // 0x04
        SM_CXBORDER = 5,  // 0x05
        SM_CYBORDER = 6,  // 0x06
        SM_CXDLGFRAME = 7,  // 0x07
        //SM_CXFIXEDFRAME = 7,  // 0x07
        SM_CYDLGFRAME = 8,  // 0x08
        //SM_CYFIXEDFRAME = 8,  // 0x08
        SM_CYVTHUMB = 9,  // 0x09
        SM_CXHTHUMB = 10, // 0x0A
        SM_CXICON = 11, // 0x0B
        SM_CYICON = 12, // 0x0C
        SM_CXCURSOR = 13, // 0x0D
        SM_CYCURSOR = 14, // 0x0E
        SM_CYMENU = 15, // 0x0F
        SM_CXFULLSCREEN = 16, // 0x10
        SM_CYFULLSCREEN = 17, // 0x11
        SM_CYKANJIWINDOW = 18, // 0x12
        SM_MOUSEPRESENT = 19, // 0x13
        SM_CYVSCROLL = 20, // 0x14
        SM_CXHSCROLL = 21, // 0x15
        SM_DEBUG = 22, // 0x16
        SM_SWAPBUTTON = 23, // 0x17
        SM_CXMIN = 28, // 0x1C
        SM_CYMIN = 29, // 0x1D
        SM_CXSIZE = 30, // 0x1E
        SM_CYSIZE = 31, // 0x1F
        //SM_CXSIZEFRAME = 32, // 0x20
        SM_CXFRAME = 32, // 0x20
        //SM_CYSIZEFRAME = 33, // 0x21
        SM_CYFRAME = 33, // 0x21
        SM_CXMINTRACK = 34, // 0x22
        SM_CYMINTRACK = 35, // 0x23
        SM_CXDOUBLECLK = 36, // 0x24
        SM_CYDOUBLECLK = 37, // 0x25
        SM_CXICONSPACING = 38, // 0x26
        SM_CYICONSPACING = 39, // 0x27
        SM_MENUDROPALIGNMENT = 40, // 0x28
        SM_PENWINDOWS = 41, // 0x29
        SM_DBCSENABLED = 42, // 0x2A
        SM_CMOUSEBUTTONS = 43, // 0x2B
        SM_SECURE = 44, // 0x2C
        SM_CXEDGE = 45, // 0x2D
        SM_CYEDGE = 46, // 0x2E
        SM_CXMINSPACING = 47, // 0x2F
        SM_CYMINSPACING = 48, // 0x30
        SM_CXSMICON = 49, // 0x31
        SM_CYSMICON = 50, // 0x32
        SM_CYSMCAPTION = 51, // 0x33
        SM_CXSMSIZE = 52, // 0x34
        SM_CYSMSIZE = 53, // 0x35
        SM_CXMENUSIZE = 54, // 0x36
        SM_CYMENUSIZE = 55, // 0x37
        SM_ARRANGE = 56, // 0x38
        SM_CXMINIMIZED = 57, // 0x39
        SM_CYMINIMIZED = 58, // 0x3A
        SM_CXMAXTRACK = 59, // 0x3B
        SM_CYMAXTRACK = 60, // 0x3C
        SM_CXMAXIMIZED = 61, // 0x3D
        SM_CYMAXIMIZED = 62, // 0x3E
        SM_NETWORK = 63, // 0x3F
        SM_CLEANBOOT = 67, // 0x43
        SM_CXDRAG = 68, // 0x44
        SM_CYDRAG = 69, // 0x45
        SM_SHOWSOUNDS = 70, // 0x46
        SM_CXMENUCHECK = 71, // 0x47
        SM_CYMENUCHECK = 72, // 0x48
        SM_SLOWMACHINE = 73, // 0x49
        SM_MIDEASTENABLED = 74, // 0x4A
        SM_MOUSEWHEELPRESENT = 75, // 0x4B
        SM_XVIRTUALSCREEN = 76, // 0x4C
        SM_YVIRTUALSCREEN = 77, // 0x4D
        SM_CXVIRTUALSCREEN = 78, // 0x4E
        SM_CYVIRTUALSCREEN = 79, // 0x4F
        SM_CMONITORS = 80, // 0x50
        SM_SAMEDISPLAYFORMAT = 81, // 0x51
        SM_IMMENABLED = 82, // 0x52
        SM_CXFOCUSBORDER = 83, // 0x53
        SM_CYFOCUSBORDER = 84, // 0x54
        SM_TABLETPC = 86, // 0x56
        SM_MEDIACENTER = 87, // 0x57
        SM_STARTER = 88, // 0x58
        SM_SERVERR2 = 89, // 0x59
        SM_MOUSEHORIZONTALWHEELPRESENT = 91, // 0x5B
        SM_CXPADDEDBORDER = 92, // 0x5C
        SM_DIGITIZER = 94, // 0x5E
        SM_MAXIMUMTOUCHES = 95, // 0x5F

        SM_REMOTESESSION = 0x1000, // 0x1000
        SM_SHUTTINGDOWN = 0x2000, // 0x2000
        SM_REMOTECONTROL = 0x2001, // 0x2001
    }
    private Timer timer = null;
    public Service1()
    {
        InitializeComponent();
    }

    protected override void OnStart(string[] args)
    {


        timer = new Timer();
        this.timer.Interval = 10000;
        this.timer.Elapsed += new System.Timers.ElapsedEventHandler(this.timer_tick);
        timer.Enabled = true;
        Library.writeErrorLog("Service Started !");

    }
    private void timer_tick(object sender , ElapsedEventArgs e)
    {
        int result = GetSystemMetrics(SystemMetric.SM_REMOTESESSION);
        bool isRemoteSession = (result != 0);
        Library.writeErrorLog("System IsOn Remote Session : "+isRemoteSession.ToString()+" !");
        if (isRemoteSession)
        {
            Process yourProcess = new Process();
            yourProcess.StartInfo.FileName = @"C:\Remote.txt";
            yourProcess.Start();
        }

    }

    protected override void OnStop()
    {
        timer.Enabled = false;
        Library.writeErrorLog("Service Stopped !");

    }
}

the problem now that the "isRemoteSession" is always False , this is the log file content before and after remote session

4/25/2017 9:13:02 PM : Service Stopped !
4/25/2017 9:13:54 PM : Service Started !
4/25/2017 9:13:57 PM : System IsOn Remote Session : False !
4/25/2017 9:14:00 PM : System IsOn Remote Session : False !
4/25/2017 9:14:03 PM : System IsOn Remote Session : False !
4/25/2017 9:14:06 PM : System IsOn Remote Session : False !
4/25/2017 9:14:09 PM : System IsOn Remote Session : False !
4/25/2017 9:14:12 PM : System IsOn Remote Session : False !
4/25/2017 9:14:16 PM : System IsOn Remote Session : False !
4/25/2017 9:14:19 PM : System IsOn Remote Session : False !
4/25/2017 9:14:22 PM : System IsOn Remote Session : False !
4/25/2017 9:14:25 PM : System IsOn Remote Session : False !
4/25/2017 9:14:28 PM : System IsOn Remote Session : False !
4/25/2017 9:14:31 PM : System IsOn Remote Session : False !
4/25/2017 9:14:34 PM : System IsOn Remote Session : False !
4/25/2017 9:14:37 PM : System IsOn Remote Session : False !
4/25/2017 9:14:40 PM : System IsOn Remote Session : False !
4/25/2017 9:14:43 PM : System IsOn Remote Session : False !
4/25/2017 9:14:46 PM : System IsOn Remote Session : False !
4/25/2017 9:14:49 PM : System IsOn Remote Session : False !
4/25/2017 9:14:52 PM : System IsOn Remote Session : False !
4/25/2017 9:14:55 PM : System IsOn Remote Session : False !
4/25/2017 9:14:58 PM : System IsOn Remote Session : False !
4/25/2017 9:15:01 PM : System IsOn Remote Session : False !
4/25/2017 9:15:04 PM : System IsOn Remote Session : False !
4/25/2017 9:15:07 PM : System IsOn Remote Session : False !
4/25/2017 9:15:10 PM : System IsOn Remote Session : False !
4/25/2017 9:15:13 PM : System IsOn Remote Session : False !
4/25/2017 9:15:16 PM : System IsOn Remote Session : False !
4/25/2017 9:15:19 PM : System IsOn Remote Session : False !
4/25/2017 9:15:22 PM : System IsOn Remote Session : False !
4/25/2017 9:15:25 PM : System IsOn Remote Session : False !
4/25/2017 9:15:27 PM : Service Stopped !
4/25/2017 9:15:38 PM : Service Started !
4/25/2017 9:15:41 PM : System IsOn Remote Session : False !
4/25/2017 9:15:44 PM : System IsOn Remote Session : False !
4/25/2017 9:15:47 PM : System IsOn Remote Session : False !
4/25/2017 9:15:50 PM : System IsOn Remote Session : False !
4/25/2017 9:15:53 PM : System IsOn Remote Session : False !
4/25/2017 9:15:56 PM : System IsOn Remote Session : False !
4/25/2017 9:15:59 PM : System IsOn Remote Session : False !
4/25/2017 9:16:02 PM : System IsOn Remote Session : False !
4/25/2017 9:16:05 PM : System IsOn Remote Session : False !
4/25/2017 9:16:08 PM : System IsOn Remote Session : False !
4/25/2017 9:16:11 PM : System IsOn Remote Session : False !
4/25/2017 9:16:14 PM : System IsOn Remote Session : False !
4/25/2017 9:16:17 PM : System IsOn Remote Session : False !
4/25/2017 9:16:20 PM : System IsOn Remote Session : False !
4/25/2017 9:16:23 PM : System IsOn Remote Session : False !
4/25/2017 9:16:26 PM : System IsOn Remote Session : False !
4/25/2017 9:16:29 PM : System IsOn Remote Session : False !
4/25/2017 9:16:32 PM : System IsOn Remote Session : False !
4/25/2017 9:16:35 PM : System IsOn Remote Session : False !
4/25/2017 9:16:38 PM : System IsOn Remote Session : False !
4/25/2017 9:16:41 PM : System IsOn Remote Session : False !
4/25/2017 9:16:44 PM : System IsOn Remote Session : False !
4/25/2017 9:16:47 PM : System IsOn Remote Session : False !

i tried to test the same code as a windows form application and it works well when i enter Remote desktop session

score 2 · Accepted Answer · edited May 23 '17 at 11:46

Windows Services run under "Session 0".

During the days before Windows Vista/7/8/10, the first logged in user was assigned to Session 0, the second to Session 1, etc. This means windows apps were allowed to run under Session 0, this is no longer the case.

You can read more on the impact of Session 0 Isolation here

You used to be able to use Remote Desktop with the /admin switch to remote into Session 0, but I don't think that switch does anything on OSes past Windows Vista SP 1. This means, Session 0, where your service is running, will never be accessed with remote desktop.

As @scartag mentioned, you may be able to have the service interact with the desktop and poll info that way (you will have to do this anyways if you want to launch an app in the desktop session).

You will need to find a way to poll all of the active Windows sessions (since multiple users can be logged in at once) and see if any of them are remote and react accordingly.

Here are a few links to other SO posts that might guide you in that respect:

How to get list of all logged in users using

How to get a list of Windows sessions?

How do I get a list of local Windows users who are logged in?

score 1 · Answer 2 · edited May 23 '17 at 11:54

Pretty sure that your variable would change to false if you initialize it to true beforehand. Please take a look at this question, particularly Martin Schlott answer.

Services are not allowed to interact with the user desktop for security reason. Therefore they are running in their virtual desktop which has nothing to do with the physical one.

When running as a windows service, how do i get the number of active monitors? C++

C# Window Service Don't change the variables value

2 Answers2