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netshareenum (netapi32)
 
.
Summary
Retrieves and enumerates over all shares on a specified machine. Can specify the amount of information gathered with the "level" parameter. The less info you get over a WAN the better because a server with 1000+ shares' information pulled over the network can be quite inefficient if you're getting a bunch of data you don't need.

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:

Please add some!

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 = new IntPtr(currentPtr.ToInt32() + 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 = new IntPtr(currentPtr.ToInt32() + nStructSize);
        }
        NetApiBufferFree(bufPtr);
        return ShareInfos.ToArray();
        }
        else
        {
        ShareInfos.Add(new SHARE_INFO_1("ERROR=" + ret.ToString(),10,string.Empty));
        return ShareInfos.ToArray();
        }
    }

}

Alternative Managed API:

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See also NetApiBufferFree API.

Documentation

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