C# Signature:
[DllImport("wtsapi32.dll", SetLastError=true)]
static extern TODO WTSEnumerateSessions(TODO);
VB Signature:
<DllImport("wtsapi32.dll", _
bestfitmapping:=True, _
CallingConvention:=CallingConvention.StdCall, _
CharSet:=CharSet.Auto, _
EntryPoint:="WTSEnumerateSessions", _
setlasterror:=True, _
ThrowOnUnmappableChar:=True)> _
Private Shared Function WTSEnumerateSessions( _
ByVal hServer As IntPtr, _
<MarshalAs(UnmanagedType.U4)> _
ByVal Reserved As Int32, _
<MarshalAs(UnmanagedType.U4)> _
ByVal Vesrion As Int32, _
ByRef ppSessionInfo As IntPtr, _
<MarshalAs(UnmanagedType.U4)> _
ByRef pCount As Int32) As Int32
End Function
User-Defined Types:
Private Enum WTS_CONNECTSTATE_CLASS
WTSActive
WTSConnected
WTSConnectQuery
WTSShadow
WTSDisconnected
WTSIdle
WTSListen
WTSReset
WTSDown
WTSInit
End Enum
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Private Structure WTS_SESSION_INFO
Dim SessionID As Int32 'DWORD integer
Dim pWinStationName As String ' integer LPTSTR - Pointer to a null-terminated string containing the name of the WinStation for this session
Dim State As WTS_CONNECTSTATE_CLASS
End Structure
Notes:
None.
Tips & Tricks:
Please add some!
Sample Code:
Option Explicit On
Option Strict On
Imports System.Runtime.InteropServices
Public Class ManagedWTSAPI
Private Enum WTS_CONNECTSTATE_CLASS
WTSActive
WTSConnected
WTSConnectQuery
WTSShadow
WTSDisconnected
WTSIdle
WTSListen
WTSReset
WTSDown
WTSInit
End Enum
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Private Structure WTS_SESSION_INFO
Dim SessionID As Int32 'DWORD integer
Dim pWinStationName As String ' integer LPTSTR - Pointer to a null-terminated string containing the name of the WinStation for this session
Dim State As WTS_CONNECTSTATE_CLASS
End Structure
Friend Structure strSessionsInfo
Dim SessionID As Integer
Dim StationName As String
Dim ConnectionState As String
End Structure
<DllImport("wtsapi32.dll", _
bestfitmapping:=True, _
CallingConvention:=CallingConvention.StdCall, _
CharSet:=CharSet.Auto, _
EntryPoint:="WTSEnumerateSessions", _
setlasterror:=True, _
ThrowOnUnmappableChar:=True)> _
Private Shared Function WTSEnumerateSessions( _
ByVal hServer As IntPtr, _
<MarshalAs(UnmanagedType.U4)> _
ByVal Reserved As Int32, _
<MarshalAs(UnmanagedType.U4)> _
ByVal Vesrion As Int32, _
ByRef ppSessionInfo As IntPtr, _
<MarshalAs(UnmanagedType.U4)> _
ByRef pCount As Int32) As Int32
End Function
<DllImport("wtsapi32.dll")> _
Private Shared Sub WTSFreeMemory(ByVal pMemory As IntPtr)
End Sub
<DllImport("wtsapi32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Function WTSOpenServer(ByVal pServerName As String) As IntPtr
End Function
<DllImport("wtsapi32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Private Shared Sub WTSCloseServer(ByVal hServer As IntPtr)
End Sub
Friend Function GetSessions(ByVal ServerName As String) As strSessionsInfo()
Dim ptrOpenedServer As IntPtr
Dim RetVal As strSessionsInfo()
Try
ptrOpenedServer = WTSOpenServer(ServerName)
Dim FRetVal As Int32
Dim ppSessionInfo As IntPtr = IntPtr.Zero
Dim Count As Int32 = 0
Try
FRetVal = WTSEnumerateSessions(ptrOpenedServer, 0, 1, ppSessionInfo, Count)
If FRetVal <> 0 Then
Dim sessionInfo() As WTS_SESSION_INFO = New WTS_SESSION_INFO(Count) {}
Dim i As Integer
For i = 0 To Count - 1 ' Step i + 1
sessionInfo(i) = CType(Marshal.PtrToStructure(ppSessionInfo, GetType(WTS_SESSION_INFO)), WTS_SESSION_INFO)
Next
WTSFreeMemory(ppSessionInfo)
Dim tmpArr(sessionInfo.GetUpperBound(0)) As strSessionsInfo
For i = 0 To tmpArr.GetUpperBound(0)
tmpArr(i).SessionID = sessionInfo(i).SessionID
tmpArr(i).StationName = sessionInfo(i).pWinStationName
tmpArr(i).ConnectionState = GetConnectionState(sessionInfo(i).State)
Next
ReDim sessionInfo(-1)
RetVal = tmpArr
Else
Throw New ApplicationException("No data retruned")
End If
Catch ex As Exception
Throw New Exception(ex.Message & vbCrLf & System.Runtime.InteropServices.Marshal.GetLastWin32Error)
End Try
Catch ex As Exception
Throw New Exception(ex.Message)
Exit Function
Finally
Try
WTSCloseServer(ptrOpenedServer)
Catch ex As Exception
End Try
End Try
Return RetVal
End Function
Private Function GetConnectionState(ByVal State As WTS_CONNECTSTATE_CLASS) As String
Dim RetVal As String
Select Case State
Case WTS_CONNECTSTATE_CLASS.WTSActive
RetVal = "Active"
Case WTS_CONNECTSTATE_CLASS.WTSConnected
RetVal = "Connected"
Case WTS_CONNECTSTATE_CLASS.WTSConnectQuery
RetVal = "Query"
Case WTS_CONNECTSTATE_CLASS.WTSDisconnected
RetVal = "Disconnected"
Case WTS_CONNECTSTATE_CLASS.WTSDown
RetVal = "Down"
Case WTS_CONNECTSTATE_CLASS.WTSIdle
RetVal = "Idle"
Case WTS_CONNECTSTATE_CLASS.WTSInit
RetVal = "Initializing."
Case WTS_CONNECTSTATE_CLASS.WTSListen
RetVal = "Listen"
Case WTS_CONNECTSTATE_CLASS.WTSReset
RetVal = "reset"
Case WTS_CONNECTSTATE_CLASS.WTSShadow
RetVal = "Shadowing"
Case Else
RetVal = "Unknown connect state"
End Select
Return RetVal
End Function
End Class
Alternative Managed API:
Do you know one? Please contribute it!
