Class to wrap Netapi32.dll functions

I have made a class for some Netapi32.dll functions in C#. I would like to know if there are any big problems with it or if there is some other function needed in general.

Functions:

• NetFileEnum

• NetShareEnum

• NetFileClose

• NetSessionEnum

• NetApiBufferFree

Here is the class:

```
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;

namespace ph03n1x
{
public class NetAPI32
{

#region Constants
protected const int MAX_PREFERRED_LENGTH = -1;
#endregion

#region StructLayout
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
public struct FILE_INFO_3
{
public int fi3_id;
public int fi3_permission;
public int fi3_num_locks;
[MarshalAs(UnmanagedType.LPWStr)]
public string fi3_pathname;
[MarshalAs(UnmanagedType.LPWStr)]
public string fi3_username;
}

[StructLayout(LayoutKind.Sequential)]
public struct SESSION_INFO_502
{
///
/// Unicode string specifying the name of the computer that established the session.
///
[MarshalAs(UnmanagedType.LPWStr)]
public string si502_cname;

///
/// Unicode string specifying the name of the user who established the session.
///
[MarshalAs(UnmanagedType.LPWStr)]
public string si502_username;

///
/// Specifies the number of files, devices, and pipes opened during the session.
///
public uint si502_num_opens;

///
/// Specifies the number of seconds the session has been active.
///
public uint si502_time;

///
/// Specifies the number of seconds the session has been idle.
///
public uint si502_idle_time;

BuildNetSessionEnumList()

• Declaring multiple variables on the same line reduces readability.

• You don't really use the SESSION_INFO_502[] results array and you can safely remove it.

Naming

• You have SHARE_INFO_2 si and FILE_INFO_3 pCurrent.

• Local variables should be named using camelCase casing. See the .NET style guide.

• You should avoid shortening variable names; that reduces readability.

• Using list for the name of each requested List also reduces readability.

• Other places that have a .NET implementation of NetSessionEnum, e.g. the PInvoke signature, have well-named parameters. Why doesn't your code use those names when calling this method? You name them res, er, tr = 0, and resume which doesn't communicate anything about them.

You should declare variables as near as possible to their usage. In the BuildNetFileEnumList() method you are declaring FILE_INFO_3 pCurrent = new FILE_INFO_3(); at the top but need it only inside of the loop.

Additionally, there's no need to use new at that point, since later in the loop you are assigning a new value to it.

You should be consistent in the style you use.

In the BuildNetSessionEnumList() method you are incrementing the pointer like

Int32 p = BufPtr.ToInt32();
    for (int i = 0; i < er; i++)
    {

        SESSION_INFO_502 si = (SESSION_INFO_502)Marshal.PtrToStructure(new IntPtr(p), typeof(SESSION_INFO_502));
        p += Marshal.SizeOf(typeof(SESSION_INFO_502));

        list.Add(si);
    }

and in the BuildNetFileEnumList() method like

for (int dwIndex = 0; dwIndex < dwReadEntries; dwIndex++)
    {

        IntPtr iPtr = new IntPtr(pBuffer.ToInt32() + (dwIndex * Marshal.SizeOf(pCurrent)));
        pCurrent = (FILE_INFO_3)Marshal.PtrToStructure(iPtr, typeof(FILE_INFO_3));

        list.Add(pCurrent);
    }

and in the BuildNetShareEnumList() method you are using a third way

Type t = typeof(SHARE_INFO_2);
    int offset = Marshal.SizeOf(t);

    for (int i = 0, lpItem = pBuffer.ToInt32(); i < entriesRead; i++, lpItem += offset)
    {
        IntPtr pItem = new IntPtr(lpItem);

        SHARE_INFO_2 si = (SHARE_INFO_2)Marshal.PtrToStructure(pItem, t);
        list.Add(si);
    }

You have declared a protected const int MAX_PREFERRED_LENGTH = -1; at class level and then again inside the BuildNetFileEnumList() method const int MAX_PREFERRED_LENGTH = -1;.

StackExchange Code Review Q#88640, answer score: 3