Microsoft KB Archive/151774

= How To Call NetUserGetInfo from Visual Basic =

Article ID: 151774

Article Last Modified on 6/29/2004

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APPLIES TO


 * Microsoft Visual Basic 6.0 Learning Edition
 * Microsoft Visual Basic 5.0 Learning Edition
 * Microsoft Visual Basic 6.0 Professional Edition
 * Microsoft Visual Basic 5.0 Professional Edition
 * Microsoft Visual Basic 6.0 Enterprise Edition
 * Microsoft Visual Basic 5.0 Enterprise Edition
 * Microsoft Visual Basic 5.0 Control Creation Edition
 * Microsoft Visual Basic 4.0 Standard Edition
 * Microsoft Visual Basic 4.0 Professional Edition
 * Microsoft Visual Basic 4.0 32-Bit Enterprise Edition

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This article was previously published under Q151774



SUMMARY
The NetUserGetInfo function is a Unicode-only Windows NT API. The last parameter of this function is a pointer to a pointer to a structure whose members contain DWORD data and pointers to Unicode strings. In order to call this function correctly from a Visual Basic application, you need to de-reference the pointer returned by the function and then you need to convert the Visual Basic string to a Unicode string and vice versa. This article illustrates these techniques in an example that calls NetUserGetInfo to retrieve a USER_INFO_3 structure from a Visual Basic application.



MORE INFORMATION
The example below uses the Win32 RtlMoveMemory function to de-reference the pointer returned by the NetUserGetInfo call. For more information on how to declare and use RtlMoveMemory function in Visual Basic, please see the following article in the Microsoft Knowledge Base:

129947 INFO: Win32 Replacement for the hmemecpy Function

For more information on how to convert Visual Basic string to Unicode string and vice versa, please see the following article in the Microsoft Knowledge Base:

145727 How To Call the Unicode Version of an API Function with VB

Step-by-Step Example
 Start Visual Basic. If Visual Basic is already running, from the File menu, choose New Project. Form1 is created by default. Add a Command button, Command1, to Form1.  Add the following code to the General Declarations section of Form1: ' definitions not specifically declared in the article:

' the servername and username params can also be declared as Longs, ' and passed Unicode memory addresses with the StrPtr function. Private Declare Function NetUserGetInfo Lib "netapi32" _ (ByVal servername As String, _                                ByVal username As String, _                                 ByVal level As Long, _                                 bufptr As Long) As Long

Const NERR_Success = 0

Private Declare Sub MoveMemory Lib "kernel32" Alias _ "RtlMoveMemory" (pDest As Any, pSource As Any, ByVal dwLength As Long)

Private Declare Function lstrlenW Lib "kernel32" (lpString As Any) As Long

' Converts a Unicode string to an ANSI string ' Specify -1 for cchWideChar and 0 for cchMultiByte to return string length. Private Declare Function WideCharToMultiByte Lib "kernel32" _ (ByVal codepage As Long, _                              ByVal dwFlags As Long, _                               lpWideCharStr As Any, _                               ByVal cchWideChar As Long, _                               lpMultiByteStr As Any, _                               ByVal cchMultiByte As Long, _                               ByVal lpDefaultChar As String, _                               ByVal lpUsedDefaultChar As Long) As Long Private Declare Function NetApiBufferFree Lib "netapi32" _ (ByVal Buffer As Long) As Long ' CodePage Const CP_ACP = 0       ' ANSI code page Private Type USER_INFO_3 usri3_name As Long             'LPWSTR in SDK usri3_password As Long         'LPWSTR in SDK usri3_password_age As Long     'DWORD in SDK usri3_priv As Long             'DWORD in SDK usri3_home_dir As Long         'LPWSTR in SDK usri3_comment As Long          'LPWSTR in SDK usri3_flags As Long            'DWORD in SDK usri3_script_path As Long      'LPWSTR in SDK usri3_auth_flags As Long       'DWORD in SDK usri3_full_name As Long        'LPWSTR in SDK usri3_usr_comment As Long      'LPWSTR in SDK usri3_parms As Long            'LPWSTR in SDK usri3_workstations As Long     'LPWSTR in SDK usri3_last_logon As Long       'DWORD in SDK usri3_last_logoff As Long      'DWORD in SDK usri3_acct_expires As Long     'DWORD in SDK usri3_max_storage As Long      'DWORD in SDK usri3_units_per_week As Long   'DWORD in SDK usri3_logon_hours As Long      'PBYTE in SDK usri3_bad_pw_count As Long     'DWORD in SDK usri3_num_logons As Long       'DWORD in SDK usri3_logon_server As Long     'LPWSTR in SDK usri3_country_code As Long     'DWORD in SDK usri3_code_page As Long        'DWORD in SDK usri3_user_id As Long          'DWORD in SDK usri3_primary_group_id As Long 'DWORD in SDK usri3_profile As Long          'LPWSTR in SDK usri3_home_dir_drive As Long   'LPWSTR in SDK usri3_password_expired As Long 'DWORD in SDK End Type

Private Sub Command1_Click Dim lpBuf As Long Dim ui3 As USER_INFO_3

' Replace "Administrator" with a valid Windows NT user name. If (NetUserGetInfo("", StrConv("Administrator", vbUnicode), 3, _ lpBuf) = NERR_Success) Then Call MoveMemory(ui3, ByVal lpBuf, Len(ui3))

MsgBox GetStrFromPtrW(ui3.usri3_name)

Call NetApiBufferFree(ByVal lpBuf) End If

End Sub

' Returns an ANSI string from a pointer to a Unicode string.

Public Function GetStrFromPtrW(lpszW As Long) As String Dim sRtn As String

sRtn = String$(lstrlenW(ByVal lpszW) * 2, 0)  ' 2 bytes/char

' WideCharToMultiByte also returns Unicode string length ' sRtn = String$(WideCharToMultiByte(CP_ACP, 0, ByVal lpszW, -1, 0, 0, 0, 0), 0)

Call WideCharToMultiByte(CP_ACP, 0, ByVal lpszW, -1, ByVal sRtn, Len(sRtn), 0, 0) GetStrFromPtrW = GetStrFromBufferA(sRtn)

End Function

' Returns the string before first null char encountered (if any) from an ANSI string.

Public Function GetStrFromBufferA(sz As String) As String If InStr(sz, vbNullChar) Then GetStrFromBufferA = Left$(sz, InStr(sz, vbNullChar) - 1) Else ' If sz had no null char, the Left$ function ' above would return a zero length string (""). GetStrFromBufferA = sz    End If   End Function 

