WTSEnumerateProcesses

1 Jun 2006 3:40 PM

Joe Green

Hi guys,

I'm trying to get a list of processes for the current Terminal Server
session in VB.NET. It's all fine apart from I can't get the
ProcessName out of the structure WTS_PROCESS_INFO. I basically get the
first character in the WTS_PROCESSINFO.ProcessName. I know it's
something to do with the fact that it's a pointer to a string, but I
can't work out what to do about it!

The relevant code is as follows:

===============================================================

    Private Declare Auto Function WTSEnumerateProcesses Lib
"wtsapi32.dll" ( _
        ByVal hServer As Int32, ByVal Reserved As Int32, _
        ByVal Version As Int32, ByRef ppProcessInfo As IntPtr, _
        ByRef pCount As Int32) As Int32

    Private Declare Auto Sub WTSFreeMemory Lib "wtsapi32.dll" (ByVal
pMemory As IntPtr)

    Private Structure WTS_PROCESS_INFO
        Dim SessionID As Integer
        Dim ProcessID As Integer
        Dim ProcessName As String
        Dim UserSid As Integer
    End Structure

        Dim ptrProcessInfo As IntPtr
        Dim lngPtrPos As Long
        Dim intReturn As Integer
        Dim intCount As Integer
        Dim intProcessCount As Integer
        Dim strucProcessInfo As WTS_PROCESS_INFO

                intReturn =
WTSEnumerateProcesses(WTS_CURRENT_SERVER_HANDLE, 0, 1, ptrProcessInfo,
intProcessCount)

                'Get the length in bytes of each structure...
                lngPtrPos = ptrProcessInfo.ToInt32()

                For intCount = 0 To intProcessCount - 1
                    strucProcessInfo = Marshal.PtrToStructure(New
IntPtr(lngPtrPos), strucProcessInfo.GetType)

                    Console.WriteLine("Process Name: " &
strucProcessInfo.ProcessName.ToString)
                    Console.WriteLine("Process ID: " &
strucProcessInfo.ProcessID.ToString)
                    Console.WriteLine("Session ID: " &
strucProcessInfo.SessionID.ToString)

                    lngPtrPos = lngPtrPos + Len(strucProcessInfo)
                Next

                Call WTSFreeMemory(ptrProcessInfo)

===============================================================

Any suggestion son this one...?!

1 Jun 2006 9:44 PM

Mattias Sjögren

>    Private Declare Auto Function WTSEnumerateProcesses Lib
>"wtsapi32.dll" ( _
>        ByVal hServer As Int32, ByVal Reserved As Int32, _
>        ByVal Version As Int32, ByRef ppProcessInfo As IntPtr, _
>        ByRef pCount As Int32) As Int32

Since you use Auto on the function ...

>    Private Structure WTS_PROCESS_INFO
>        Dim SessionID As Integer
>        Dim ProcessID As Integer
>        Dim ProcessName As String
>        Dim UserSid As Integer
>    End Structure

.... you should use it on the structure as well. Add the
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)>
attribute.

Mattias

--
Mattias Sjögren [C# MVP] mattias @ mvps.org
http://www.msjogren.net/dotnet/ | http://www.dotnetinterop.com
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