Microsoft KB Archive/113688

= How to Use WNetGetUser in Windows for Workgroups from VB 3.0 =

Article ID: 113688

Article Last Modified on 12/9/2003

-

APPLIES TO


 * Microsoft Visual Basic 2.0 Standard Edition
 * Microsoft Visual Basic 3.0 Professional Edition
 * Microsoft Visual Basic 2.0 Professional Edition
 * Microsoft Visual Basic 3.0 Professional Edition

-



This article was previously published under Q113688



SUMMARY
The information from this article is taken from the following Microsoft Knowledge Base article:

96772 : INF: How to Use WNetGetUser in Windows for Workgroups

The information is duplicated here to include sample code that is converted for use in Visual Basic.

WNetGetUser is documented on page 194 in the Microsoft Windows Device Driver Kit (DDK) "Device Driver Adaptation Guide" for version 3.1. This function can be used to retrieve the current user name of the user logged on to the network underlying Windows. However, when using this function in Microsoft Windows for Workgroups, WNetGetUser returns WN_SUCCESS but the user name string is empty. Because WFWNET.DRV is a multinet driver, the network that supports WNetGetUser must be activated before using this function.



MORE INFORMATION
Until the release of the Windows for Workgroups Software Development Kit (SDK), the WNetGetUser function was used internally by Windows. It is documented in the Windows version 3.1 "Device Driver Adaptation Guide" for network device driver developers.

Now the Windows for Workgroups SDK allows you to call WNetGetUser from an application. However, when using this function on a system with a multinet driver, you must activate the supporting network by first using MNetSetNextTarget. If the target network has not been set, the function returns WN_SUCCESS but the returned string for the user name is empty. This is documented in the description of MNetSetNextTarget in the Windows for Workgroups SDK.

It is not sufficient to just call MNetSetNextTarget before WNetGetUser. The current target network may not support WNetGetUser. To set the target network to use WNetGetUser correctly, you must number the networks and call WNetGetUser for each network. If WNetGetUser does not return WN_SUCCESS, then increment the network number for the next target network and iterate the loop. If the loop iterates through all of the networks but WNetGetUser never returns WN_SUCCESS, then none of the target networks support WNetGetUser. The following sample code demonstrates how to do this.

Step-by-Step Example
 Start a new project in Visual Basic. Form1 is created by default.  Add the following code to the General Declarations section of Form1: ' Enter each of the following Declare statements on one, single line: Declare Function WNetGetUser Lib "wfwnet.drv" (ByVal szUser As String,     nBufferSize As Integer) As Integer Declare Function MNetNetworkEnum Lib "wfwnet.drv" (lphNetwork As Integer) As Integer Declare Function MNetSetNextTarget Lib "wfwnet.drv" (ByVal hNetwork As Integer) As Integer

' The following function determines the logged-in user in Windows for ' Workgroups: Function MultiNetGetUser (UserName$) As Integer

Dim hNetDrv As Integer Dim wRetEnum As Integer, ret As Integer Dim wRetGetUser As Integer Dim cb As Integer Dim Found As Integer

Found = False ' Grab the 1st network: hNetDrv = 0 wRetEnum = MNetNetworkEnum(hNetDrv)

' Loop while there are installed networks: While (wRetEnum = 0) And Not Found user$ = Space$(255) cb = Len(user$)

' Make sure correct network is accessed in next WNetGetUser call: ret = MNetSetNextTarget(hNetDrv)

' Get the user: wRetGetUser = WNetGetUser(user$, cb)

' Check for success: If wRetGetUser = 0 Then ' Just grab the relevant characters: UserName$ = Left$(user$, cb - 1) MsgBox UserName$,, "WNetGetUser" Found = True End If

' Get the next network: wRetEnum = MNetNetworkEnum(hNetDrv) Wend If Not Found Then MsgBox "WNetGetUser not supported on any of the Multinet subnets" End If

MultiNetGetUser = Found

End Function

 Put a command button (Command1) on the form.  Add the following code to the Command1 Click event: Sub Command1_Click r = MultiNetGetUser(UserName$) End Sub

 Save the project. Run the program. A message box should pop up displaying the user name.</ol>

NOTE: To determine whether a system supports multinet operations, MNetGetCaps can be used with WNNC_NET_TYPE. The return value has the WNNC_NET_MultiNet (0x8000) set if the system supports multinet operations.

Additional query words: 2.00 3.00 3.10 3.11 username multi-net

Keywords: KB113688

-

[mailto:TECHNET@MICROSOFT.COM Send feedback to Microsoft]

© Microsoft Corporation. All rights reserved.