How To Enumerate 16-bit Tasks on Window NT Using Visual Basic

Steps to Create the Example

1. Start a new Standard EXE project in Visual Basic. Form1 is created by default.
2. Add one CommandButton to the form.
3. Set the forms AutoReDraw property to True.
4. Select Project from the Menu and add a new module to the project. Module1 is created by default.
5. Copy the following code into the Code window of Module1:

   Option Explicit
   
   Declare Function VDMEnumProcessWOW Lib "VDMDBG.dll" _ 
   (ByVal fp As Long, lparam As Long) As Integer 
   
   Declare Function VDMEnumTaskWOWEx Lib "VDMDBG.dll " _ 
   (dwProcessId As Long, ByVal fp As Long, lparam As Long) As Integer 
   
   Declare Function lstrcpy Lib "kernel32" _ 
   (ByVal lpString1 As Any, ByVal lpString2 As Any) As Long 
   
   Public Function PROCESSENUMPROC _
   (ByVal dwProcessId As Long, ByVal dwAttributes As Long, _
   lpUserDefined As Long) As Boolean
     
       Form1.Cls
       Form1.Print "dwProcessId: " & dwProcessId
       Form1.Print "dwAttributes: " & dwAttributes & vbCrLf 
   ' Pass the Process ID to this next function to enumerate that Process.
       Call VDMEnumTaskWOWEx(ByVal dwProcessId, AddressOf TASKENUMPROCEX, 0)
   
   End Function
   
   Public Function TASKENUMPROCEX _ 
   (ByVal dwThreadId As Long, ByVal hMod16 As Long, _ 
   ByVal hTask16 As Long, ByVal pszModName As Long, _ 
   ByVal pszFileName As Long, lpUserDefined As Long) As Boolean 
   
   ' Print Enumerated task of the 16bit process
       Form1.Print "dwThreadId: " & dwThreadId & vbCrLf & _
       "hMod16: " & hMod16 & vbCrLf & "hTask16: " & hTask16 & vbCrLf & _
       "pszModName: " & PointerToString(pszModName) & vbCrLf & _
       "pszFileName: " & PointerToString(pszFileName) & vbCrLf & _
       "lpUserDefined: " & lpUserDefined & vbCrLf
   ' Return value is false until there are no more tasks to enumerate.  
   End Function
   
   Private Function PointerToString(lPtr As Long) As String
   Dim sTemp As String * 255, Retval As Long
   ' Parse String Values returned from function call. 
   
       Retval = lstrcpy(sTemp, lPtr)
       If (InStr(1, sTemp, Chr(0)) = 0) Then
            PointerToString = ""
       Else
            PointerToString = Left(sTemp, InStr(1, sTemp, Chr(0)) - 1)
       End If
       
   End Function
   					

6. Copy the following code into the Code window of Form1:

   Private Sub Command1_Click() 
   
   Dim Retval As Long 
   ' Call VDMEnumProcessWOW to beging the enumeration
      Retval = VDMEnumProcessWOW(AddressOf PROCESSENUMPROC, 0)
   
   End Sub 
   					

7. Save the Project and then press F5 to run the project. The enumerated processes will list on the form.

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