C# Signature:
[DllImport("Netapi32.dll", CharSet=CharSet.Unicode)]
private static extern int NetShareEnum(
StringBuilder ServerName,
int level,
ref IntPtr bufPtr,
uint prefmaxlen,
ref int entriesread,
ref int totalentries,
ref int resume_handle
);
VB Signature:
Declare Unicode Function NetShareEnum Lib "netapi32.dll" _
(ByVal ServerName As StringBuilder, _
ByVal level As Integer, _
ByRef BufPtr As IntPtr,
ByVal prefmaxbufferlen As Integer, _
ByRef entriesread As Integer, _
ByRef totalentries As Integer, _
ByRef resume_handle As Integer) As Integer
VB Signature:
<DllImport("Netapi32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Public Shared Function NetShareEnum( _
ByVal ServerName As StringBuilder, _
ByVal level As Integer, _
ByRef BufPtr As IntPtr, _
ByVal prefmaxbufferlen As Integer, _
ByRef entriesread As Integer, _
ByRef totalentries As Integer, _
ByRef resume_handle As Integer) As Integer
End Function
User-Defined Types:
if you use C# Sample code;
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Unicode)]
public struct SHARE_INFO_0
{
public string shi0_netname;
}
const uint MAX_PREFERRED_LENGTH = 0xFFFFFFFF;
const int NERR_Success = 0;
Notes:
[28-06-2007]
VB Enumeration Function Added by JustAl
[2006-07-05]
VB Alternate Signature code added by KRONOS
[2004-06-11]
VB Def and Sample code added by RACKLEY
[2004-08-31]
C# Def and Sample code added by K.MORONO
Tips & Tricks:
I believe that all of these samples are slightly incorrect in that they do not deal with the case where NetShareEnum does not retrieve all of the shares on a server in a single call. The caller is supposed to check for ERROR_MORE_DATA and then do the appropriate thing. This may be an edge case not worrying about, but anyone writing code for big environments should validate the assumption that all shares will be fetched with a single call.
Sample Code:
[VB.NET] - Added by JustAl
''' <summary>
''' Enumerates the shares on Windows NT
''' </summary>
''' <param name="server">The server name</param>
''' <param name="shares">The ShareCollection</param>
Protected Shared Sub EnumerateSharesNT(ByVal server As String, ByVal shares As ShareCollection)
Dim level As Integer = 2
Dim entriesRead As Integer, totalEntries As Integer, nRet As Integer, hResume As Integer = 0
Dim pBuffer As IntPtr = IntPtr.Zero
Try
nRet = NetShareEnum(server, level, pBuffer, -1, entriesRead, totalEntries, _
hResume)
If ERROR_ACCESS_DENIED = nRet Then
'Need admin for level 2, drop to level 1
level = 1
nRet = NetShareEnum(server, level, pBuffer, -1, entriesRead, totalEntries, _
hResume)
End If
If NO_ERROR = nRet AndAlso entriesRead > 0 Then
Dim t As Type = IIf((2 = level), GetType(SHARE_INFO_2), GetType(SHARE_INFO_1))
Dim offset As Integer = Marshal.SizeOf(t)
Dim i As Integer = 0, lpItem As Integer = pBuffer.ToInt32()
While i < entriesRead
Dim pItem As New IntPtr(lpItem)
If 1 = level Then
Dim si As SHARE_INFO_1 = DirectCast(Marshal.PtrToStructure(pItem, t), SHARE_INFO_1)
shares.Add(si.NetName, "Access Denied", si.ShareType, si.Remark)
Else
Dim si As SHARE_INFO_2 = DirectCast(Marshal.PtrToStructure(pItem, t), SHARE_INFO_2)
shares.Add(si.NetName, si.Path, si.ShareType, si.Remark)
End If
i += 1
lpItem += offset
End While
End If
Finally
' Clean up buffer allocated by system
If IntPtr.Zero <> pBuffer Then
NetApiBufferFree(pBuffer)
End If
End Try
End Sub
Sample Code:
Dim currentPtr As IntPtr
Dim BufPtr As IntPtr 'in
Dim dwEntriesread As Integer 'out
Dim dwTotalentries As Integer 'out
Dim dwResumehandle As Integer 'out
Dim nStructSize As Integer
Dim shi2 As SHARE_INFO_2
Dim cnt As Long 'share enumeration counter
Dim SvrNameBldr As New StringBuilder(ServerName)
retval = NetShareEnum(SvrNameBldr, 2, BufPtr, MAX_PREFERRED_LENGTH, dwEntriesread, dwTotalentries, dwResumehandle)
If retval = NERR_Success And retval <> ERROR_MORE_DATA Then
currentPtr = BufPtr
nStructSize = Marshal.SizeOf(GetType(SHARE_INFO_2))
' Enumerate over all shares on the server and find the any/all shares that point
' to c:\deletemeplease and delete those shares.
For cnt = 0 To dwEntriesread - 1
shi2 = Marshal.PtrToStructure(currentPtr, GetType(SHARE_INFO_2))
If System.String.Compare(shi2.shi2_path, "c:\deletemeplease" True) = 0 Then
DelRetVal = NetShareDel(ServerName, shi2.shi2_netname, 0)
End If
currentPtr = New IntPtr(currentPtr.ToInt32 + Marshal.SizeOf(GetType(SHARE_INFO_2)))
Next
End If
Call NetApiBufferFree(BufPtr)
[C#]
PUT TextBox control,ListBox control and Button control on your Form.
private void button1_Click(object sender, System.EventArgs e)
{
listBox1.Items.Clear();
int entriesread = 0;
int totalentries = 0;
int resume_handle = 0;
int nStructSize = Marshal.SizeOf(typeof(SHARE_INFO_0));
IntPtr bufPtr = IntPtr.Zero;
StringBuilder server = new StringBuilder(textBox1.Text);
int ret = NetShareEnum(server,0,ref bufPtr,MAX_PREFERRED_LENGTH,ref entriesread,ref totalentries,ref resume_handle);
if (ret == NERR_Success)
{
IntPtr currentPtr = bufPtr;
for (int i = 0;i<entriesread;i++)
{
SHARE_INFO_0 shi0 = (SHARE_INFO_0)Marshal.PtrToStructure(currentPtr,typeof(SHARE_INFO_0));
listBox1.Items.Add(shi0.shi0_netname);
currentPtr += nStructSize;
}
NetApiBufferFree(bufPtr);
}
else
{
listBox1.Items.Add("失敗 = " + ret.ToString());
}
}
[C#]
Sample Class for SHARE_INFO_1 (sharename, sharetype, remark)
public class GetNetShares
{
#region External Calls
[DllImport("Netapi32.dll", SetLastError = true)]
static extern int NetApiBufferFree(IntPtr Buffer);
[DllImport("Netapi32.dll", CharSet = CharSet.Unicode)]
private static extern int NetShareEnum(
StringBuilder ServerName,
int level,
ref IntPtr bufPtr,
uint prefmaxlen,
ref int entriesread,
ref int totalentries,
ref int resume_handle
);
#endregion
#region External Structures
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct SHARE_INFO_1
{
public string shi1_netname;
public uint shi1_type;
public string shi1_remark;
public SHARE_INFO_1(string sharename, uint sharetype, string remark)
{
this.shi1_netname = sharename;
this.shi1_type = sharetype;
this.shi1_remark = remark;
}
public override string ToString()
{
return shi1_netname;
}
}
#endregion
const uint MAX_PREFERRED_LENGTH = 0xFFFFFFFF;
const int NERR_Success = 0;
private enum NetError : uint
{
NERR_Success = 0,
NERR_BASE = 2100,
NERR_UnknownDevDir = (NERR_BASE + 16),
NERR_DuplicateShare = (NERR_BASE + 18),
NERR_BufTooSmall = (NERR_BASE + 23),
}
private enum SHARE_TYPE : uint
{
STYPE_DISKTREE = 0,
STYPE_PRINTQ = 1,
STYPE_DEVICE = 2,
STYPE_IPC = 3,
STYPE_SPECIAL = 0x80000000,
}
public SHARE_INFO_1[] EnumNetShares(string Server)
{
List<SHARE_INFO_1> ShareInfos = new List<SHARE_INFO_1>();
int entriesread = 0;
int totalentries = 0;
int resume_handle = 0;
int nStructSize = Marshal.SizeOf(typeof(SHARE_INFO_1));
IntPtr bufPtr = IntPtr.Zero;
StringBuilder server = new StringBuilder(Server);
int ret = NetShareEnum(server, 1, ref bufPtr, MAX_PREFERRED_LENGTH, ref entriesread, ref totalentries, ref resume_handle);
if (ret == NERR_Success)
{
IntPtr currentPtr = bufPtr;
for (int i = 0; i < entriesread; i++)
{
SHARE_INFO_1 shi1 = (SHARE_INFO_1)Marshal.PtrToStructure(currentPtr, typeof(SHARE_INFO_1));
ShareInfos.Add(shi1);
currentPtr += nStructSize;
}
NetApiBufferFree(bufPtr);
return ShareInfos.ToArray();
}
else
{
ShareInfos.Add(new SHARE_INFO_1("ERROR=" + ret.ToString(),10,string.Empty));
return ShareInfos.ToArray();
}
}
}
'[VB.Net]
' What is mission. This one works well. Share type 0 is a normal shared folder. I don't know the other types
' but hey, the mission here is to list shares.
' Added by: Pieter E Jordaan - South Africa
'
' Usage : ServerShareCollection = GetSharesFromHost("Server")
' For Each s As ShareType In ServerShareCollection.Shares
' msgbox (s.name)
' next
'
Imports System
Imports System.Runtime.InteropServices
Imports System.text
Module ShareModule
Public ServerShareCollection As ShareCollection
Public Structure ShareType
Dim Name As String
Dim Path As String
Dim Type As Integer
Dim Remark As String
End Structure
Public Structure ShareCollection
Dim Shares() As ShareType
Dim ShareCount As Integer
Sub Clear()
Shares = Nothing
End Sub
Sub Add(ByVal Name As String, ByVal Path As String, ByVal Type As Integer, ByVal Remark As String)
If Shares Is Nothing Then
ReDim Shares(0)
Shares(0).Name = Name
Shares(0).Path = Path
Shares(0).Type = Type
Shares(0).Remark = Remark
Else
ReDim Preserve Shares(Shares.Length)
Shares(Shares.Length - 1).Name = Name
Shares(Shares.Length - 1).Path = Path
Shares(Shares.Length - 1).Type = Type
Shares(Shares.Length - 1).Remark = Remark
End If
If Type = 0 Then ShareCount = ShareCount + 1
End Sub
End Structure
Declare Unicode Function NetShareEnum Lib "netapi32.dll" _
(ByVal ServerName As StringBuilder, _
ByVal level As Integer, _
ByRef BufPtr As IntPtr, _
ByVal prefmaxbufferlen As Integer, _
ByRef entriesread As Integer, _
ByRef totalentries As Integer, _
ByRef resume_handle As Integer) As Integer
Declare Unicode Function NetShareGetInfo Lib "netapi32.dll" _
(ByVal ServerName As String, _
ByVal ShareName As String, _
ByVal Level As Integer, _
ByRef BufPtr As IntPtr) As Integer
Declare Unicode Function NetApiBufferFree Lib "netapi32.dll" _
(ByRef buffer As IntPtr) As Long
#Region "Constants"
Const MAX_PREFERRED_LENGTH As Integer = -1 ' originally 0
Const ERROR_SUCCESS As Long = 0& ' No errors encountered.
Const NERR_Success As Long = 0&
Const ERROR_ACCESS_DENIED As Long = 5& ' The user has insufficient privilege for this operation.
Const ERROR_NOT_ENOUGH_MEMORY As Long = 8& ' Not enough memory
Const ERROR_NETWORK_ACCESS_DENIED As Long = 65& ' Network access is denied.
Const ERROR_INVALID_PARAMETER As Long = 87& ' Invalid parameter specified.
Const ERROR_BAD_NETPATH As Long = 53& ' The network path was not found.
Const ERROR_INVALID_NAME As Long = 123& ' Invalid name
Const ERROR_INVALID_LEVEL As Long = 124& ' Invalid level parameter.
Const ERROR_MORE_DATA As Long = 234& ' More data available, buffer too small.
Const NERR_BASE As Long = 2100&
Const NERR_NetNotStarted As Long = 2102& ' Device driver not installed.
Const NERR_RemoteOnly As Long = 2106& ' This operation can be performed only on a server.
Const NERR_ServerNotStarted As Long = 2114& ' Server service not installed.
Const NERR_BufTooSmall As Long = 2123& ' Buffer too small for fixed-length data.
Const NERR_RemoteErr As Long = 2127& ' Error encountered while remotely. executing function
Const NERR_WkstaNotStarted As Long = 2138& ' The Workstation service is not started.
Const NERR_BadTransactConfig As Long = 2141& ' The server is not configured for this transaction; IPC$ is not shared.
Const NERR_NetNameNotFound As Long = (NERR_BASE + 210) ' Sharename not found.
Const NERR_InvalidComputer As Long = 2351& ' Invalid computername specified.
#End Region ' "Constants"
#Region "API Calls With Structures"
<StructLayout(LayoutKind.Sequential)> _
Structure SHARE_INFO_1
<MarshalAs(UnmanagedType.LPWStr)> Dim netname As String
Public ShareType As Integer
<MarshalAs(UnmanagedType.LPWStr)> Dim Remark As String
End Structure
<StructLayout(LayoutKind.Sequential)> _
Structure SHARE_INFO_2
<MarshalAs(UnmanagedType.LPWStr)> Dim shi2_netname As String
Dim shi2_type As Integer
<MarshalAs(UnmanagedType.LPWStr)> Dim shi2_remark As String
Dim shi2_permissions As Integer
Dim shi2_max_uses As Integer
Dim shi2_current_uses As Integer
<MarshalAs(UnmanagedType.LPWStr)> Dim shi2_path As String
<MarshalAs(UnmanagedType.LPWStr)> Dim shi2_passwd As String
End Structure
#End Region ' "API Calls With Structures"
Public Function GetSharesFromHost(ByVal server As String) As ShareCollection
Dim Shares As New ShareCollection
Shares.Clear()
Dim level As Integer = 2
Dim svr As New StringBuilder(server)
Dim entriesRead As Integer, totalEntries As Integer, nRet As Integer, hResume As Integer = 0
Dim pBuffer As IntPtr = IntPtr.Zero
Try
nRet = NetShareEnum(svr, level, pBuffer, -1, entriesRead, totalEntries, _
hResume)
If ERROR_ACCESS_DENIED = nRet Then
'Need admin for level 2, drop to level 1
level = 1
nRet = NetShareEnum(svr, level, pBuffer, -1, entriesRead, totalEntries, _
hResume)
End If
If 0 = nRet AndAlso entriesRead > 0 Then
Dim t As Type = IIf((2 = level), GetType(SHARE_INFO_2), GetType(SHARE_INFO_1))
Dim offset As Integer = Marshal.SizeOf(t)
Dim i As Integer = 0, lpItem As Integer = pBuffer.ToInt32()
While i < entriesRead
Dim pItem As New IntPtr(lpItem)
If 1 = level Then
Dim si As SHARE_INFO_1 = DirectCast(Marshal.PtrToStructure(pItem, t), SHARE_INFO_1)
Shares.Add(si.netname, "Access Denied", si.ShareType, si.Remark)
Else
Dim si As SHARE_INFO_2 = DirectCast(Marshal.PtrToStructure(pItem, t), SHARE_INFO_2)
Shares.Add(si.shi2_netname, si.shi2_path, si.shi2_type, si.shi2_remark)
End If
i += 1
lpItem += offset
End While
End If
Return Shares
Finally
' Clean up buffer allocated by system
If IntPtr.Zero <> pBuffer Then
NetApiBufferFree(pBuffer)
End If
End Try
Return Shares
End Function
End Module
' Enjoy!
Alternative Managed API:
Do you know one? Please contribute it!
See also NetApiBufferFree API.
