Microsoft KB Archive/192689

= How To Get UNC Path From a Mapped Network Share's Drive Letter =

Article ID: 192689

Article Last Modified on 7/14/2004

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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 Q192689



SUMMARY
Most network client software allows you to refer to network drives through the use of mapped drive letters or the use of syntax known as UNC notation (Universal Naming Convention). Use of UNC notation requires that you know the name of the server and share, while a mapped drive letter only requires the drive letter once the connection has been established. At times, it may be necessary to determine the UNC path to a server given only it's mapped drive letter. This article demonstrates a method for obtaining this information.



Step-by-Step Example
 Map a drive letter to any available network share and make note of the letter assigned. Create a new Visual Basic project. Form1 is created by default. Add a CommandButton to Form1.  Paste the following code into Form1's code window: Option Explicit

Private Const RESOURCETYPE_ANY = &H0 Private Const RESOURCE_CONNECTED = &H1

Private Type NETRESOURCE dwScope As Long dwType As Long dwDisplayType As Long dwUsage As Long lpLocalName As Long lpRemoteName As Long lpComment As Long lpProvider As Long End Type

Private Declare Function WNetOpenEnum Lib "mpr.dll" Alias _ "WNetOpenEnumA" (ByVal dwScope As Long, ByVal dwType As Long, _        ByVal dwUsage As Long, lpNetResource As Any, lphEnum As Long) _ As Long

Private Declare Function WNetEnumResource Lib "mpr.dll" Alias _ "WNetEnumResourceA" (ByVal hEnum As Long, lpcCount As Long, _        lpBuffer As Any, lpBufferSize As Long) As Long

Private Declare Function WNetCloseEnum Lib "mpr.dll" ( _        ByVal hEnum As Long) As Long

Private Declare Function lstrlen Lib "kernel32" Alias "lstrlenA" _ (ByVal lpString As Any) As Long

Private Declare Function lstrcpy Lib "kernel32" Alias "lstrcpyA" _ (ByVal lpString1 As Any, ByVal lpString2 As Any) As Long

Private Sub Command1_Click MsgBox LetterToUNC("F:") ' <<<<<<<<<<<<<<<<<<<<<<<<<<<<< End Sub

Function LetterToUNC(DriveLetter As String) As String Dim hEnum As Long Dim NetInfo(1023) As NETRESOURCE Dim entries As Long Dim nStatus As Long Dim LocalName As String Dim UNCName As String Dim i As Long Dim r As Long

' Begin the enumeration nStatus = WNetOpenEnum(RESOURCE_CONNECTED, RESOURCETYPE_ANY, _           0&, ByVal 0&, hEnum)

LetterToUNC = "Drive Letter Not Found"

'Check for success from open enum If ((nStatus = 0) And (hEnum <> 0)) Then ' Set number of entries entries = 1024

' Enumerate the resource nStatus = WNetEnumResource(hEnum, entries, NetInfo(0), _              CLng(Len(NetInfo(0))) * 1024)

' Check for success If nStatus = 0 Then For i = 0 To entries - 1 ' Get the local name LocalName = "" If NetInfo(i).lpLocalName <> 0 Then LocalName = Space(lstrlen(NetInfo(i).lpLocalName) + 1) r = lstrcpy(LocalName, NetInfo(i).lpLocalName) End If

' Strip null character from end If Len(LocalName) <> 0 Then LocalName = Left(LocalName, (Len(LocalName) - 1)) End If

If UCase$(LocalName) = UCase$(DriveLetter) Then ' Get the remote name UNCName = "" If NetInfo(i).lpRemoteName <> 0 Then UNCName = Space(lstrlen(NetInfo(i).lpRemoteName) _                          + 1) r = lstrcpy(UNCName, NetInfo(i).lpRemoteName) End If

' Strip null character from end If Len(UNCName) <> 0 Then UNCName = Left(UNCName, (Len(UNCName) _ - 1))                    End If

' Return the UNC path to drive LetterToUNC = UNCName

' Exit the loop Exit For End If              Next i            End If         End If

' End enumeration nStatus = WNetCloseEnum(hEnum) End Function

 Change the code in Command1's Click event to refer to the drive letter created by step 1. Run the sample. Click the CommandButton. The UNC path to the mapped drive is shown in a message box.</li></ol>

Additional query words: kbDSupport kbDSD kbVBp kbVBp400 kbVBp500 kbVBp600 KbVBA kbAPI kbSDKWin32 kbWNet

Keywords: kbhowto KB192689

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