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