Visual Basic

NET_API_STATUS NetServerEnum(
  LPCWSTR servername,        // [in] Reserved - must be 0
                             //
  DWORD level,               // [in] Level - 100 or 101
                             //
  LPBYTE* bufptr,            // [out] Pointer to the buffer that receives the data.
                             // This buffer is allocated by the system and must be 
                             // freed using the NetApiBufferFree function. Note 
                             // that you must free the buffer even if the function 
                             // fails with ERROR_MORE_DATA. 
                             //
  DWORD prefmaxlen,          // [in] Prefered max length of returned data (bytes)
                             //
  LPDWORD entriesread,       // [out] Pointer to a value that receives the 
                             // count of elements actually enumerated.
                             //
  LPDWORD totalentries,      // [out] Pointer to a value that receives the total 
                             // number of visible servers and workstations on 
                             // the network. 
                             //
  DWORD servertype,          // [in] Specifies a value that filters the server 
                             // entries to return from the enumeration. 
                             //
  LPCWSTR domain,            // [in] Pointer to a constant string that specifies 
                             // the name of the domain for which a list of 
                             // servers is to be returned.
                             //
  LPDWORD resume_handle      // [out] Reserved - must be 0
);

Public Declare Function NetServerEnum Lib "netapi32" ( _
    ByVal ServerName As IntPtr, _
    ByVal Level As Integer, _
    ByRef Buffer As IntPtr, _
    ByVal PrefMaxLen As Integer, _
    ByRef EntriesRead As Integer, _
    ByRef TotalEntries As Integer, _
    ByVal ServerType As Integer, _
    <MarshalAs(UnmanagedType.LPWStr)> _
    ByVal Domain As String, _
    ByVal ResumeHandle As IntPtr _
) As Integer

...
Dim EntriesRead As Integer = 0
Dim TotalEntries As Integer = 0
Dim Buffer As IntPtr = IntPtr.Zero

Dim nRes As Integer = NetServerEnum( _
    IntPtr.Zero, _
    Level, _
    Buffer, _
    -1, _
    EntriesRead, _
    TotalEntries, _
    ServerType, _
    DomainName, _
    IntPtr.Zero _
)

Try
    'Do some stuff here
    ...
Finally
    'Clean up buffer
    If Not(Buffer.Equals(IntPtr.Zero)) Then
        NetApiBufferFree(Buffer)
    End If
End Try

TempBufPtr = New IntPtr(TempBufPtr.ToInt32() + SI_SIZE_101)

Imports System.Runtime.InteropServices
'
Public Enum PlatformID
    DOS = 300
    OS2 = 400
    NT  = 500
    OSF = 600
    VMS = 700
End Enum
'
<Flags> _
Public Enum ServerType
    None = &H00000000
    Workstation = &H00000001
    Server = &H00000002
    SQLServer = &H00000004
    DomainController = &H00000008
    DomainBackupController = &H00000010
    TimeSource = &H00000020
    AFP = &H00000040
    Novell = &H00000080
    DomainMember = &H00000100
    PrintQueue = &H00000200
    Dialin = &H00000400
    Xenix = &H00000800
    Unix = Xenix
    NT = &H00001000
    WFW = &H00002000
    MFPN = &H00004000
    NTServer = &H00008000
    PotentialBrowser = &H00010000
    BackupBrowser = 0x00020000
    MasterBrowser = &H00040000
    DomainMaster = &H00080000
    OSF = &H00100000
    VMS = &H00200000
    Windows = &H00400000
    DFS = &H00800000
    ClusterNT = &H01000000
    TerminalServer = &H02000000
    DCE = &H10000000
    AlternateXPort = &H20000000
    ListOnly = &H40000000
    DomainEnum = &H80000000
    All = &HFFFFFFFF
End Enum
'
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Public Structure SERVER_INFO_101 
    '
    Public dwPlatformID As PlatformID 
    '
    <MarshalAs(UnmanagedType.LPWStr)> _
    Public lpszServerName As String
    '
    Public dwVersionMajor As Integer
    Public dwVersionMinor As Integer
    '
    Public dwType As ServerType
    '
    <MarshalAs(UnmanagedType.LPWStr)> _
    Public lpszComment As String
End Structure

Imports System.Runtime.InteropServices
...
Dim tS As Type = GetType(SERVER_INFO_101)
Dim currentItem As SERVER_INFO_101
currentItem = DirectCast(Marshal.PtrToStructure(TempBufPtr, tS), tS)
Dim ServerName As String = currentItem.lpszServerName

Const ERROR_NO_MORE_ITEMS = 259&
Const HKEY_CURRENT_CONFIG = &H80000005
Const HKEY_LOCAL_MACHINE = &H80000002
Private Declare Function RegCloseKey Lib "advapi32.dll" (ByVal hKey As Long) As Long
Private Declare Function RegOpenKey Lib "advapi32.dll" Alias "RegOpenKeyA" (ByVal hKey As Long, ByVal lpSubKey As String, phkResult As Long) As Long
Private Declare Function RegEnumKeyEx Lib "advapi32.dll" Alias "RegEnumKeyExA" (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpName As String, lpcbName As Long, ByVal lpReserved As Long, ByVal lpClass As String, lpcbClass As Long, lpftLastWriteTime As Any) As Long
Private Declare Function RegEnumValue Lib "advapi32.dll" Alias "RegEnumValueA" (ByVal hKey As Long, ByVal dwIndex As Long, ByVal lpValueName As String, lpcbValueName As Long, ByVal lpReserved As Long, lpType As Long, lpData As Any, lpcbData As Long) As Long
Private Sub Form_Load()
    Dim hKey As Long, Cnt As Long, sName As String, sData As String, Ret As Long, RetData As Long
    Const BUFFER_SIZE As Long = 255
    'Set the forms graphics mode to persistent
    Me.AutoRedraw = True
    Me.Print "RegEnumKeyEx"
    Ret = BUFFER_SIZE
    'Open the registry key
    If RegOpenKey(HKEY_LOCAL_MACHINE, "Hardware", hKey) = 0 Then
        'Create a buffer
        sName = Space(BUFFER_SIZE)
        'Enumerate the keys
<font color="red">
        While RegEnumKeyEx(hKey, Cnt, sName, Ret, ByVal 0&, vbNullString, ByVal 0&, ByVal 0&) <> ERROR_NO_MORE_ITEMS
            'Show the enumerated key
            Me.Print "  " + Left$(sName, Ret)
            'prepare for the next key
            Cnt = Cnt + 1
            sName = Space(BUFFER_SIZE)
            Ret = BUFFER_SIZE
        Wend
</font>
        'close the registry key
        RegCloseKey hKey
    Else
        Me.Print "  Error while calling RegOpenKey"
    End If
    Me.Print vbCrLf + "RegEnumValue"
    Cnt = 0
    'Open a registry key
    If RegOpenKey(HKEY_LOCAL_MACHINE, "Software\Microsoft\Windows\CurrentVersion", hKey) = 0 Then
        'initialize
        sName = Space(BUFFER_SIZE)
        sData = Space(BUFFER_SIZE)
        Ret = BUFFER_SIZE
        RetData = BUFFER_SIZE
        'enumerate the values
        While RegEnumValue(hKey, Cnt, sName, Ret, 0, ByVal 0&, ByVal sData, RetData) <> ERROR_NO_MORE_ITEMS
            'show data
            If RetData > 0 Then Me.Print "  " + Left$(sName, Ret) + "=" + Left$(sData, RetData - 1)
            'prepare for next value
            Cnt = Cnt + 1
            sName = Space(BUFFER_SIZE)
            sData = Space(BUFFER_SIZE)
            Ret = BUFFER_SIZE
            RetData = BUFFER_SIZE
        Wend
        'Close the registry key
        RegCloseKey hKey
    Else
        Me.Print "  Error while calling RegOpenKey"
    End If
End Sub