Drives Collection (VB6)

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I’m working on this incomplete Function using the FSO to get a drive UNC. (Probably reinventing the wheel; the unwritten part of the function wil replace the drive letter with the UNC if applicable.) What I don’t understand is why I first have to set the Drives Collection, how come I can’t go straight to the Drive Item?

Function FileUNC(strPath as String) as String
Dim fso As FileSystemObject
Dim collDrives As Drives
Dim objDrive As Drive

Set fso = CreateObject(“Scripting.FileSystemObject”)

If fso.FileExists(strPath) Then
strFilePath = Left(fso.GetAbsolutePathName(strPath), 1)
Set collDrives = fso.Drives ‘ if I set the collection here the code works, but …
‘ How come neither of the next lines is valid as an alternative?
‘ Set objDrive = fso.Drives(strPath)
‘ Set objDrive = fso.Drives.Item(strPath)
‘ which would simplify this part to “With objDrive” …
With collDrives(strPath)
If .DriveType = 3 Then FileUNC = .ShareName
End With
Debug.Print FileUNC
End If
Set objDrive = Nothing
Set collDrives = Nothing
Set fso = Nothing
End Sub

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Strictly a guess. DRIVES is not a collection but a method of the fso object that returns a collection of drives.

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Strictly a guess. DRIVES is not a collection but a method of the fso object that returns a collection of drives.

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According to one reliable source (VB and VBA In A Nutshell – Language Reference by Paul Lomax (O’Reilly)), the FSO Drives collection Item property returns a Drive object (as expected), but the Item property Key parameter must be the drive letter, not a numerical index: “This is an unusual collection, since the drive’s index value (its ordinal position in the collection) can’t be used; attempting to do so generates runtime error 5, ‘Invalid procedure call or argument.'” Further explanation for this flaky behavior not provided. Sample code using Item property to return a Drive object:

Public Sub TestGetDrive(ByRef sDriveSpec As String)

Dim fso As New FileSystemObject
Dim d As Drive

Set d = fso.Drives("C")
' Set d = fso.GetDrive(sDriveSpec)
Debug.Print d.DriveLetter, d.Path, d.DriveType

Set fso = Nothing
Set d = Nothing

End Sub

Due to this unorthodox behavior, it is simpler to just loop thru the Drives collection using For Each… Next, or, for a single drive whose path is known, use GetDrive method. The attached text file shows some other examples of using FSO or API functions to get drive info, including UNC paths, etc.

HTH

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PS: You may be getting error if using full path instead of just drive letter, or drive letter with colon and/or colon & backslash. All of these should work:

Set d = fso.Drives(“C”)
Set d = fso.Drives(“C:”)
Set d = fso.Drives(“C:”)

For some reason thought you were trying to use numerical index, which definitely will not work….

HTH

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PS: You may be getting error if using full path instead of just drive letter, or drive letter with colon and/or colon & backslash. All of these should work:

Set d = fso.Drives(“C”)
Set d = fso.Drives(“C:”)
Set d = fso.Drives(“C:”)

For some reason thought you were trying to use numerical index, which definitely will not work….

HTH

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VBA in a NutShell by Lomax was my reference for trying to figure it out, but I don’t know the FSO well. As you can see by the code, I’m trying to get the UNC from the first letter, the drive letter, from a string containing a full path and filename. I’ll try it from code you posted. Thanks for your help, Mark.

Edit. FWIW, here’s what I ended up with.

Public Function GetFileUNC(ByRef strFilePath As String) As String
Dim fso As FileSystemObject
Dim strDriveName As String

Set fso = CreateObject(“Scripting.FileSystemObject”)
With fso
If .FolderExists(strFilePath) Or .FileExists(strFilePath) Then
strDriveName = Left(.GetAbsolutePathName(strFilePath), 1)
With .GetDrive(strDriveName)
If .DriveType = 3 Then
GetFileUNC = Replace(strFilePath, strDriveName & “:”, .ShareName, , , vbTextCompare)
Else
GetFileUNC = strFilePath
End If
End With
End If
End With
Set fso = Nothing
End Function

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John,

Here is another possibility using WSH :

Function ConvertToUNC(strPath As String)
Dim WshNetwork, strDrive As String
Set WshNetwork = CreateObject(“WScript.Network”)
strDrive = Left(strPath, 2)
Set oDrives = WshNetwork.EnumNetworkDrives
For i = 0 To oDrives.Count – 1 Step 2
If oDrives.Item(i) = strDrive Then
ConvertToUNC = Replace(strPath, strDrive, oDrives.Item(i + 1))
Exit Function
End If
Next
End Function

If you are just looking for the UNC of a drive letter, you need to include a semicolon , e.g ConvertToUNC(“F:”)

Andrew

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Thanks, Andrew.

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Thanks, Andrew.

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John,

Here is another possibility using WSH :

Function ConvertToUNC(strPath As String)
Dim WshNetwork, strDrive As String
Set WshNetwork = CreateObject(“WScript.Network”)
strDrive = Left(strPath, 2)
Set oDrives = WshNetwork.EnumNetworkDrives
For i = 0 To oDrives.Count – 1 Step 2
If oDrives.Item(i) = strDrive Then
ConvertToUNC = Replace(strPath, strDrive, oDrives.Item(i + 1))
Exit Function
End If
Next
End Function

If you are just looking for the UNC of a drive letter, you need to include a semicolon , e.g ConvertToUNC(“F:”)

Andrew

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VBA in a NutShell by Lomax was my reference for trying to figure it out, but I don’t know the FSO well. As you can see by the code, I’m trying to get the UNC from the first letter, the drive letter, from a string containing a full path and filename. I’ll try it from code you posted. Thanks for your help, Mark.

Edit. FWIW, here’s what I ended up with.

Public Function GetFileUNC(ByRef strFilePath As String) As String
Dim fso As FileSystemObject
Dim strDriveName As String

Set fso = CreateObject(“Scripting.FileSystemObject”)
With fso
If .FolderExists(strFilePath) Or .FileExists(strFilePath) Then
strDriveName = Left(.GetAbsolutePathName(strFilePath), 1)
With .GetDrive(strDriveName)
If .DriveType = 3 Then
GetFileUNC = Replace(strFilePath, strDriveName & “:”, .ShareName, , , vbTextCompare)
Else
GetFileUNC = strFilePath
End If
End With
End If
End With
Set fso = Nothing
End Function

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According to one reliable source (VB and VBA In A Nutshell – Language Reference by Paul Lomax (O’Reilly)), the FSO Drives collection Item property returns a Drive object (as expected), but the Item property Key parameter must be the drive letter, not a numerical index: “This is an unusual collection, since the drive’s index value (its ordinal position in the collection) can’t be used; attempting to do so generates runtime error 5, ‘Invalid procedure call or argument.'” Further explanation for this flaky behavior not provided. Sample code using Item property to return a Drive object:

Public Sub TestGetDrive(ByRef sDriveSpec As String)

Dim fso As New FileSystemObject
Dim d As Drive

Set d = fso.Drives("C")
' Set d = fso.GetDrive(sDriveSpec)
Debug.Print d.DriveLetter, d.Path, d.DriveType

Set fso = Nothing
Set d = Nothing

End Sub

Due to this unorthodox behavior, it is simpler to just loop thru the Drives collection using For Each… Next, or, for a single drive whose path is known, use GetDrive method. The attached text file shows some other examples of using FSO or API functions to get drive info, including UNC paths, etc.

HTH

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You could always just use the API method:

Private Declare Function WNetGetConnection Lib “mpr.dll” Alias “WNetGetConnectionA” (ByVal lpszLocalName As String, ByVal lpszRemoteName As String, cbRemoteName As Long) As Long
Function GetUNCPath(strDrivePath As String) As String
Dim strTemp As String
Dim dwReturn As Long
strTemp = Space(255)
dwReturn = WNetGetConnection(strDrivePath, strTemp, 255)
If dwReturn = 0 Then
strTemp = Trim(strTemp)
GetUNCPath = Left(strTemp, Len(strTemp) – 1)
Else
GetUNCPath = “Error”
End If
End Function

So on my machine, GetUNCPath(“T:”) returns NasData which is the share path of our T: drive. I have it just returning ‘Error’ if something is wrong, but there is a bunch of specifics you can get from the error message, like ‘network is not present’, etc.

Hope this helps….

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You could always just use the API method:

Private Declare Function WNetGetConnection Lib “mpr.dll” Alias “WNetGetConnectionA” (ByVal lpszLocalName As String, ByVal lpszRemoteName As String, cbRemoteName As Long) As Long
Function GetUNCPath(strDrivePath As String) As String
Dim strTemp As String
Dim dwReturn As Long
strTemp = Space(255)
dwReturn = WNetGetConnection(strDrivePath, strTemp, 255)
If dwReturn = 0 Then
strTemp = Trim(strTemp)
GetUNCPath = Left(strTemp, Len(strTemp) – 1)
Else
GetUNCPath = “Error”
End If
End Function

So on my machine, GetUNCPath(“T:”) returns NasData which is the share path of our T: drive. I have it just returning ‘Error’ if something is wrong, but there is a bunch of specifics you can get from the error message, like ‘network is not present’, etc.

Hope this helps….

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