Visual Basic

<code>Imports WindowsHookLib	'http://www.codeproject.com/KB/vb/WindowsHookLib.aspx?

Friend WithEvents KbHook As LLKeyboardHook

Private Declare Function OpenWindowStation Lib "user32.dll" Alias "OpenWindowStationA" (ByVal lpszWinSta As String, ByVal fInherit As Boolean, ByVal dwDesiredAccess As Int32) As Int32

Private Declare Function OpenDesktop Lib "user32.dll" Alias "OpenDesktopA" (ByVal lpszDesktop As String, ByVal dwFlags As Int32, ByVal fInherit As Boolean, ByVal dwDesiredAccess As Int32) As Int32

Private Declare Function SetProcessWindowStation Lib "user32.dll" (ByVal hWinSta As Int32) As Int32

Private Declare Function SetThreadDesktop Lib "user32.dll" (ByVal hDesktop As Int32) As Int32


'Start the service with a login handler
Protected Overrides Sub OnStart(ByVal args() As String)
	Dim objLog As EventLog = New EventLog("Security")
	AddHandler objLog.EntryWritten, AddressOf SecurityLog_OnEntryWritten
	objLog.EnableRaisingEvents = True
End Sub 'OnStart


Private Sub SecurityLog_OnEntryWritten(ByVal [source] As Object, ByVal e As EntryWrittenEventArgs)

	'Only want user login events
        If e.Entry.InstanceId <> 528 OrElse e.Entry.UserName.Contains("SERVICE") Then
            Return
        End If

MakeServiceInteractive()'http://www.codeguru.com/forum/showthread.php?t=238942
'Service then does other stuff on separate threads I'd like to abort when there's no active user
End Sub 'SecurityLog_OnEntryWritten


Private Sub MakeServiceInteractive() 
    Dim lngDefaultDesktop As Int32
    Dim lngWinSta0 As Int32

    lngWinSta0 = OpenWindowStation("WinSta0", False, &H37F)
    If SetProcessWindowStation(lngWinSta0) <> 0 Then 'success
          lngDefaultDesktop = OpenDesktop("Default", 0&, False, &H8L)
          If SetThreadDesktop(lngDefaultDesktop) <> 0 Then 'success
              KbHook = New LLKeyboardHook
              KbHook.InstallHook()
              WriteLog("KbHook state: " & KbHook.GetState.ToString())
		'I can step through to a log entry of "KbHook state: Installed" so all seems well, but handler never gets hit.
          End If
    End If
End Sub 'MakeServiceInteractive


Private Sub KbHook_KeyDown(ByVal sender As Object, ByVal e As WindowsHookLib.KeyEventArgs) Handles KbHook.KeyDown
    WriteLog(e.KeyCode.ToString & " Pressed") 'never gets called :confused:
End Sub 'KbHook_KeyDown</code>