ACC: How to Retrieve Workgroup Information Under Win32

• Microsoft Access versions 7.0, 97

SUMMARY

Advanced: Requires expert coding, interoperability, and multiuser skills.

Using the Win32 application programming interface (API), you can retrieve network information, such as the user name, workgroup, domain, and computer name, about the currently running computer when you are running Microsoft Windows NT or Microsoft Windows 95.

This article assumes that you are familiar with Visual Basic for Applications and with creating Microsoft Access applications using the programming tools provided with Microsoft Access. For more information about Visual Basic for Applications, please refer to your version of the "Building Applications with Microsoft Access" manual.

MORE INFORMATION

NetWkstaGetInfo(), a Windows API, takes advantage of the Windows NT security model and returns the computer, workgroup, and domain. Windows 95, however, can get the current user name with the network independent function call WNetGetUser and can get the current computer name with the function GetComputerName(). The code samples demonstrate the use of all three.

The following example shows how to use Visual Basic and the Win32 API to retrieve network information:

1. Create a module and type the following lines in the Declarations section:

   NOTE: You may have some Microsoft Windows API functions defined in an existing Microsoft Access library; therefore, your declarations may be duplicates. If you receive a duplicate procedure name error message, remove or comment out the declarations statement in your code.

   NOTE: All Declare statements must be typed exactly as shown, including capitalization, because Win32 names are case-sensitive. To help eliminate errors by you or others who use your Declare statements, create Alias clauses for Declare statements that do not have an existing Alias. As long as the Alias is correctly spelled and capitalized, it does not matter how the function name is capitalized.

   NOTE: Make sure to click the Compile All command on the Run menu to verify that you do not receive any compilation errors.

         Option Explicit
         Type WKSTA_INFO_101
            wki101_platform_id As Long
            wki101_computername As Long
            wki101_langroup As Long
            wki101_ver_major As Long
            wki101_ver_minor As Long
            wki101_lanroot As Long
         End Type
   
         Type WKSTA_USER_INFO_1
            wkui1_username As Long
            wkui1_logon_domain As Long
            wkui1_logon_server As Long
            wkui1_oth_domains As Long
         End Type
   
         Declare Function WNetGetUser& Lib "Mpr" Alias "WNetGetUserA" _
            (lpName As Any, ByVal lpUserName$, lpnLength&)
         Declare Function NetWkstaGetInfo& Lib "Netapi32" _
            (strServer As Any, ByVal lLevel&, pbBuffer As Any)
         Declare Function NetWkstaUserGetInfo& Lib "Netapi32" _
            (reserved As Any, ByVal lLevel&, pbBuffer As Any)
         Declare Sub lstrcpyW Lib "Kernel32" (dest As Any, ByVal src As Any)
         Declare Sub lstrcpy Lib "Kernel32" (dest As Any, ByVal src As Any)
         Declare Sub RtlMoveMemory Lib "Kernel32" _
            (dest As Any, src As Any, ByVal size&)
         Declare Function NetApiBufferFree& Lib "Netapi32" (ByVal buffer&)
   
   

2. Type the following procedure:

         Function GetWorkstationInfo()
            Dim ret As Long, buffer(512) As Byte, i As Integer
            Dim wk101 As WKSTA_INFO_101, pwk101 As Long
            Dim wk1 As WKSTA_USER_INFO_1, pwk1 As Long
            Dim cbusername As Long, username As String
            Dim computername As String, langroup As String, logondomain As _
               String
   
            ' Clear all of the display values.
            computername = "": langroup = "": username = "": logondomain = ""
   
            ' Windows 95 or NT - call WNetGetUser to get the name of the user.
            username = Space(256)
            cbusername = Len(username)
            ret = WNetGetUser(ByVal 0&, username, cbusername)
            If ret = 0 Then
               ' Success - strip off the null.
               username = Left(username, InStr(username, Chr(0)) - 1)
            Else
               username = ""
            End If
   
         '================================================================
         ' The following section works only under Windows NT
         '================================================================
   
            'NT only - call NetWkstaGetInfo to get computer name and lan group
            ret = NetWkstaGetInfo(ByVal 0&, 101, pwk101)
            RtlMoveMemory wk101, ByVal pwk101, Len(wk101)
            lstrcpyW buffer(0), wk101.wki101_computername
            ' Get every other byte from Unicode string.
            i = 0
            Do While buffer(i) <> 0
               computername = computername & Chr(buffer(i))
               i = i + 2
            Loop
            lstrcpyW buffer(0), wk101.wki101_langroup
            i = 0
            Do While buffer(i) <> 0
               langroup = langroup & Chr(buffer(i))
               i = i + 2
            Loop
            ret = NetApiBufferFree(pwk101)
   
            ' NT only - call NetWkstaUserGetInfo.
            ret = NetWkstaUserGetInfo(ByVal 0&, 1, pwk1)
            RtlMoveMemory wk1, ByVal pwk1, Len(wk1)
            lstrcpyW buffer(0), wk1.wkui1_logon_domain
            i = 0
            Do While buffer(i) <> 0
               logondomain = logondomain & Chr(buffer(i))
               i = i + 2
            Loop
            ret = NetApiBufferFree(pwk1)
   
         '================================================================
         'End NT-specific section
         '================================================================
   
            debug.print computername, langroup, username, logondomain
         End Function
   
   

3. To test this function, type the following line in the Debug window, and then press ENTER:

         GetWorkstationInfo
   

   Note that your data is printed in the Debug Window.

1. Create a module and type the following lines in the Declarations section:

          Option Explicit
          Private Declare Function GetComputerName _
          Lib "kernel32" Alias "GetComputerNameA" ( _
          ByVal lpBuffer As String, nSize As Long) As Long
   

          Private Const MAX_COMPUTERNAME_LENGTH As Long = 15&
   

2. Type the following procedure:

          Public Function CurrentMachineName() As String
          Dim lSize As Long
          Dim sBuffer As String
          sBuffer = Space$(MAX_COMPUTERNAME_LENGTH + 1)
          lSize = Len(sBuffer)
   

             If GetComputerName(sBuffer, lSize) Then
                 CurrentMachineName = Left$(sBuffer, lSize)
             End If
   
          End Function
   
   

3. To test this function, type the following line in the Debug window, and then press ENTER:

          ?CurrentMachineName()
   

   Note that your data is printed to the Debug Window.

REFERENCES

For an example of this article in Microsoft Access version 2.0, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q101676
   TITLE:      ACC: How to Retrieve Windows for Workgroups User
               Information

Keywords          : kbprg PgmApi
Version           : 7.0 97
Platform          : WINDOWS
Hardware          : x86
Issue type        : kbhowto