Archive for February, 2010

Using Process related API calls in VB.NET

0
1 year ago
by Jason Shuler in
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I’m working on an app that will monitor the number of GDI Objects of another process (in this case, the spooler)

To do this in VB.NET requires an API call to GetGuiResources. While testing, I was using Process.GetProcesses to get a list of all the available processes, passed the handle of each process to the API function, and writing the result to a textbox.

Problem was, all process that I did not own throw security errors, even when I set the app to run with elevated privs. The internet once again failed me, and I stumbled across the solution while browsing the system.diagnostics.process documentation on MSDN.

The solution is to call Process.EnterDebugMode() before getting your process list and calling the API, then calling Process.LeaveDebugMode() when you are done.

MSDN EnterDebugMode Documentation

Here is an example. remember to run with elevate privs, and create a multiline textbox called txtOut.

Public Class Form1
  Declare Function GetGuiResources Lib "user32" (ByVal hProcess As Long, ByVal uiFlags As Long) As Long
  ' uiFlags: 0 - Count of GDI objects
  ' uiFlags: 1 - Count of USER objects

  Private Sub btnGo_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnGo.Click
    Dim procList As Process()

    Dim TYPE_GDI As UInteger = 0

    Process.EnterDebugMode()
    procList = Process.GetProcesses

    For Each proc As Process In procList
      Dim objCnt As Long
      Try
        objCnt = GetGuiResources(proc.Handle, TYPE_GDI)
      Catch ex As Exception
        objCnt = -1
      End Try

      txOut.AppendText(proc.ProcessName & vbTab & "GDI: " & objCnt.ToString & vbNewLine)
    Next proc

    Process.LeaveDebugMode()

  End Sub
End Class

Getting Active Directory info for the current user in VB.net in 2 lines

6
2 years ago
by Jason Shuler in
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Don’t listen to the internet – getting account information from active directory for the current user is simple and easy in Visual Basic .NET – particularly if you are using Framework 3.5.

You don’t need to do any stinking LDAP queries, or lookups, or credential passings – it’s all made simple using System.DirectoryServices.AccountManagement. Observe.

First, go to the references tab in project properties, click add reference, and find “System.DirectoryServices.AccountManagement” – no need to add “System.DirectoryServices”.

Now, in your application, add the following lines:

Dim currentADUser As System.DirectoryServices.AccountManagement.UserPrincipal
currentADUser = System.DirectoryServices.AccountManagement.UserPrincipal.Current

(It’s even simpler if you import the namespace)

Poof. That’s it! You are done.

currentADUser is a strongly typed object containing attributes for most of the active directory properties you need = such as display name, email address, primary group membership, exchange mailbox info, etc, etc.

Say you want to get the current user’s email address. You could do it like so (after the previous code):

Dim userEmail as string = currentADUser.EmailAddress

That’s it. 1 additional line.

How about a concrete example – here is the problem I wanted to solve. Send an email message from the current user for error reporting – Make sure to change the To: email address, and the smtp server name, and this should be a drop-in solution:

  Private Sub report_error(ByVal errorMessage As String)
    Dim currentADUser As System.DirectoryServices.AccountManagement.UserPrincipal
    currentADUser = System.DirectoryServices.AccountManagement.UserPrincipal.Current
    Dim mailClient As New System.Net.Mail.SmtpClient("smtpserver.company.local")
    mailClient.Send(currentADUser.DisplayName & " <" & currentADUser.EmailAddress & ">", _
                    "notifications@company.com", _
                    "ERROR REPORT: Application error for " & currentADUser.DisplayName, _
                    errorMessage)
  End Sub

Hope this helps!

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