Q192689: HOWTO: Get UNC Path From a Mapped Network Share’s Drive Letter
Article: Q192689
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s):
Keyword(s): kbGrpDSVB
Last Modified: 01-MAR-2002
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The information in this article applies to:
- Microsoft Visual Basic Learning Edition for Windows, versions 6.0, 5.0
- Microsoft Visual Basic Professional Edition for Windows, versions 6.0, 5.0
- Microsoft Visual Basic Enterprise Edition for Windows, versions 6.0, 5.0
- Microsoft Visual Basic Control Creation Edition for Windows, version 5.0
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0
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SUMMARY
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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.
MORE INFORMATION
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Step-by-Step Example
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1. Map a drive letter to any available network share and make note of the letter
assigned.
2. Create a new Visual Basic project. Form1 is created by default.
3. Add a CommandButton to Form1.
4. 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
5. Change the code in Command1's Click event to refer to the drive letter
created by step 1.
6. Run the sample.
7. Click the CommandButton. The UNC path to the mapped drive is shown in a
message box.
Additional query words: kbDSupport kbDSD kbVBp kbVBp400 kbVBp500 kbVBp600 KbVBA kbAPI kbSDKWin32 kbWNet
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Keywords : kbGrpDSVB
Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500Search kbVB500 kbVB600 kbVB400Search kbVB400 kbZNotKeyword3
Version : :4.0,5.0,6.0
Issue type : kbhowto
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