EnumFolder

Option Explicit
Public Const MAX_PATH = 260

'GetDriveType return values
Public Const DRIVE_REMOVABLE = 2
Public Const DRIVE_FIXED = 3
Public Const DRIVE_REMOTE = 4
Public Const DRIVE_CDROM = 5
Public Const DRIVE_RAMDISK = 6

Type FILETIME
    dwLowDateTime As Long
    dwHighDateTime As Long
End Type

Type WIN32_FIND_DATA
    dwFileAttributes As Long
    ftCreationTime As FILETIME
    ftLastAccessTime As FILETIME
    ftLastWriteTime As FILETIME
    nFileSizeHigh As Long
    nFileSizeLow As Long
    dwReserved0 As Long
    dwReserved1 As Long
    cFileName As String * MAX_PATH
    cAlternate As String * 14
End Type
Public Declare Function GetLogicalDriveStrings _
    Lib "kernel32" Alias "GetLogicalDriveStringsA" _
    (ByVal nBufferLength As Long, _
    ByVal lpBuffer As String) As Long
Public Declare Function FindFirstFile _
    Lib "kernel32" Alias "FindFirstFileA" _
    (ByVal lpFileName As String, _
    lpFindFileData As WIN32_FIND_DATA) As Long
Public Declare Function FindNextFile _
    Lib "kernel32" Alias "FindNextFileA" _
    (ByVal hFindFile As Long, _
    lpFindFileData As WIN32_FIND_DATA) As Long
Public Declare Function FindClose _
    Lib "kernel32" (ByVal hFindFile As Long) As Long

'flags for the user options
Public displayExpanded As Boolean
Public displaySorted As Boolean
Public NoOfDrives As Integer
Public Function TrimNull(startstr As String) As String
    Dim pos As Integer
    pos = InStr(startstr, Chr$(0))
    
    If pos Then
        TrimNull = Left$(startstr, pos - 1)
        Exit Function
    End If
    
    'if this far, there was no Chr$(0), so return the string
    TrimNull = startstr
    
End Function

Public Sub GetAllDrivesFolders(tvwTree As Control, nodParentNode As Node)
    'this routine uses a pre-dimmed array to speed up
    'processing.  Initially, the array is DIM'med to
    '200 elements; in the While loop it is increased
    'another 200 elements when "found Mod 200 = 0"
    '(or the number found divided by 200 equals 0).
    'At the end of the loop, it is resized down to the
    'total found.  This is significantly faster than
    'using a Redim Preserve statement for each element found.
    Dim nodX As Node
    
    Dim WFD As WIN32_FIND_DATA
    Dim hFile As Long
    
    Dim sFile As String
    Dim sPath As String
    
    Dim i As Integer
    Dim r As Long
    Dim found As Integer
    
    'assign the fullpath property to the path to search,
    'assuring that the path is qualified.
    If Right$(nodParentNode.FullPath, 1)   "\" Then
        sPath = nodParentNode.FullPath & "\"
    Else: sPath = nodParentNode.FullPath
    End If
    
    'find the first file matching the parameter \*.*
    hFile = FindFirstFile(sPath & "*.*" & Chr$(0), WFD)
    
    'reset the counter flag
    found = 0
    ReDim fArray(200)
    
    If hFile  -1 Then
        sFile = TrimNull(WFD.cFileName)
        
        WFD.dwFileAttributes = vbDirectory
        
        While FindNextFile(hFile, WFD)
            
            sFile = TrimNull(WFD.cFileName)
            
            'ignore the 2 standard root entries
            If (sFile   ".") And (sFile   "..") Then
                
                If (WFD.dwFileAttributes And vbDirectory) Then
                    
                    found = found + 1
                    
                    'if found is at 200, then add some more array elements
                    If found Mod 200 = 0 Then ReDim Preserve fArray(found + 100)
                    fArray(found) = sFile
                End If
            End If
        Wend
    End If
    
    r = FindClose(hFile)
    
    'trim down the array to equal the elements found
    ReDim Preserve fArray(found)
    
    'add the folders to the treeview
    For i = 1 To found
        
        Set nodX = tvwTree.Nodes.Add(nodParentNode.Key, _
            tvwChild, _
            sPath & fArray(i) & "Dir", _
            fArray(i))
        
        'and get some more
        GetAllDrivesFolders tvwTree, nodX
        
    Next i
    
    nodParentNode.Sorted = displaySorted
    nodParentNode.Expanded = displayExpanded
End Sub

Private Sub Form_Load()
    
    'centre the form
    Me.Move (Screen.Width - Me.Width) / 2, (Screen.Height - Me.Height) / 2
    
    'set initial options
    displaySorted = True
    displayExpanded = False
    
    'load the system drives
    GetSystemDrives
    
    'store the initial number of treeview elements for
    'later subtraction when presenting the total number
    'of files loaded (tvwControl_click routine)
    NoOfDrives = tvwControl.Nodes.Count
    
    lblMessage = "Click on any drive letter to load it's folders."
End Sub

Private Sub cmdEnd_Click()
    Unload Me
    Set Form1 = Nothing
    End
    
End Sub

Private Sub GetSystemDrives()
    Dim nodX As Node
    Dim r As Long
    Dim allDrives As String
    Dim currDrive As String
    Dim drvIcon As Integer
    
    'get the list of all available drives
    allDrives = rgbGetAvailableDrives()
    
    Do Until allDrives = Chr$(0)
        
        'strip off one drive item from the allDrives$
        currDrive = StripNulls(allDrives)
        
        'we can't have the trailing slash, so ..
        currDrive = Left$(currDrive, 2)
        
        'add the drive to the treeview
        Set nodX = tvwControl.Nodes.Add(, tvwChild, _
            currDrive & "Dir", _
            currDrive)
        nodX.Expanded = True
        
    Loop
    
    'force sorting of the drive letters
    nodX.Sorted = True
End Sub

Private Function rgbGetAvailableDrives() As String
    'returns a single string of available drive
    'letters, each separated by a chr$(0)
    Dim r As Long
    Dim tmp As String
    
    tmp = Space$(64)
    r& = GetLogicalDriveStrings(Len(tmp), tmp)
    
    rgbGetAvailableDrives = Trim$(tmp)
End Function

Private Function StripNulls(startstr As String) As String
    'Take a string separated by a chr$(0), and split off 1 item, and
    'shorten the string so that the next item is ready for removal.
    
    Dim pos As Integer
    Dim c As Integer
    pos = InStr(startstr$, Chr$(0))
    
    If pos Then
        
        StripNulls = Mid$(startstr, 1, pos - 1)
        startstr = Mid$(startstr, pos + 1, Len(startstr))
        Exit Function
        
    End If
End Function

Private Sub tvwControl_Click()
    Dim nodX As Node
    
    'show a wait message for long searches
    lblMessage = "Searching drive " & tvwControl.SelectedItem & " for folders ... please wait"
    DoEvents
    
    'identify the selected node
    Set nodX = tvwControl.SelectedItem
    
    'verify it's valid
    If (UCase$(Right$(nodX.Key, 3)) = "DIR") And (nodX.Children = 0) Then
        GetAllDrivesFolders tvwControl, nodX
    End If
    
    'subtract NoOfDrives because initial drives loaded
    'should not be counted as a folder
    lblMessage = "Total folders displayed : " & tvwControl.Nodes.Count - NoOfDrives
    
End Sub

'Comment
'When the form loads, the treeview is filled with the available drives via
'the GetSystemDrives routine. Clicking a drive letter invokes the
'tvwControl_Click() routine, which calls the GetAllDrivesFolders Sub.
'The first execution of GetAllDrivesFolders returns the first-level of
'folders (try commenting out the line "GetAllDrivesFolders tvwTree, nodX"
'to demonstrate), and for each folder added to the treeview, the routine
'again calls GetAllDrivesFolders passing the node item to search from.
'Once no more folders are found (that is, there are no more folders within
'a given level), control returns to the calling line, which loads the next
'folder and restarts the process until all the first-level folders have
'been searched for sub-folders
 This code is intended to demonstrate how to recursively search for all
folders on a target drive using the Win95/NT4 APIs FindFirstFile and
FindNextFile, and display the results into a treeview control.
FindFirstFile, on successful finding of a file matching the filespec passed
returns a handle for subsequent calls by FindNextFile, and the data of the
retrieved file in the WIN32_FIND_DATA structure. The structure member
dwFileAttributes, when AND'd with the VB constant vbDirectory can be used
to determine if the returned item is a file or folder. The routine stores
the folder names in an array, and once a pass is completed at each level,
creates the treeview data.
Start a new project, and to the form add a command button (cmdEnd), a
Treeview control (tvwControl) and an autosizing label (lblMessage) as
indicated in the illustration.
Place the following into the general declarations area of a bas module:

Option Explicit
Public Const MAX_PATH = 260

'GetDriveType return values

Public Const DRIVE_REMOVABLE = 2
Public Const DRIVE_FIXED = 3
Public Const DRIVE_REMOTE = 4
Public Const DRIVE_CDROM = 5
Public Const DRIVE_RAMDISK = 6

Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type

Type WIN32_FIND_DATA
dwFileAttributes As Long
ftCreationTime As FILETIME
ftLastAccessTime As FILETIME
ftLastWriteTime As FILETIME
nFileSizeHigh As Long
nFileSizeLow As Long
dwReserved0 As Long
dwReserved1 As Long
cFileName As String * MAX_PATH
cAlternate As String * 14
End Type
Public Declare Function GetLogicalDriveStrings _
Lib "kernel32" Alias "GetLogicalDriveStringsA" _
(ByVal nBufferLength As Long, _
ByVal lpBuffer As String) As Long
Public Declare Function FindFirstFile _
Lib "kernel32" Alias "FindFirstFileA" _
(ByVal lpFileName As String, _
lpFindFileData As WIN32_FIND_DATA) As Long
Public Declare Function FindNextFile _
Lib "kernel32" Alias "FindNextFileA" _
(ByVal hFindFile As Long, _
lpFindFileData As WIN32_FIND_DATA) As Long
Public Declare Function FindClose _
Lib "kernel32" (ByVal hFindFile As Long) As Long

'flags for the user options

Public displayExpanded As Boolean
Public displaySorted As Boolean
Public NoOfDrives As Integer
Public Function TrimNull(startstr As String) As String
Dim pos As Integer
pos = InStr(startstr, Chr$(0))

If pos Then
TrimNull = Left$(startstr, pos - 1)
Exit Function
End If

'if this far, there was no Chr$(0), so return the string

TrimNull = startstr

End Function

Public Sub GetAllDrivesFolders(tvwTree As Control, nodParentNode As Node)
'this routine uses a pre-dimmed array to speed up

'processing. Initially, the array is DIM'med to

'200 elements; in the While loop it is increased

'another 200 elements when "found Mod 200 = 0"

'(or the number found divided by 200 equals 0).

'At the end of the loop, it is resized down to the

'total found. This is significantly faster than

'using a Redim Preserve statement for each element found.

Dim nodX As Node

Dim WFD As WIN32_FIND_DATA
Dim hFile As Long

Dim sFile As String
Dim sPath As String

Dim i As Integer
Dim r As Long
Dim found As Integer

'assign the fullpath property to the path to search,

'assuring that the path is qualified.

If Right$(nodParentNode.FullPath, 1) "\" Then
sPath = nodParentNode.FullPath & "\"
Else: sPath = nodParentNode.FullPath
End If

'find the first file matching the parameter \*.*

hFile = FindFirstFile(sPath & "*.*" & Chr$(0), WFD)

'reset the counter flag

found = 0
ReDim fArray(200)

If hFile -1 Then
sFile = TrimNull(WFD.cFileName)

WFD.dwFileAttributes = vbDirectory

While FindNextFile(hFile, WFD)

sFile = TrimNull(WFD.cFileName)

'ignore the 2 standard root entries

If (sFile ".") And (sFile "..") Then

If (WFD.dwFileAttributes And vbDirectory) Then

found = found + 1

'if found is at 200, then add some more array elements

If found Mod 200 = 0 Then ReDim Preserve fArray(found + 100)
fArray(found) = sFile
End If
End If
Wend
End If

r = FindClose(hFile)

'trim down the array to equal the elements found

ReDim Preserve fArray(found)

'add the folders to the treeview

For i = 1 To found

Set nodX = tvwTree.Nodes.Add(nodParentNode.Key, _
tvwChild, _
sPath & fArray(i) & "Dir", _
fArray(i))

'and get some more

GetAllDrivesFolders tvwTree, nodX

Next i

nodParentNode.Sorted = displaySorted
nodParentNode.Expanded = displayExpanded
End Sub

Private Sub Form_Load()

'centre the form

Me.Move (Screen.Width - Me.Width) / 2, (Screen.Height - Me.Height) / 2

'set initial options

displaySorted = True
displayExpanded = False

'load the system drives

GetSystemDrives

'store the initial number of treeview elements for

'later subtraction when presenting the total number

'of files loaded (tvwControl_click routine)

NoOfDrives = tvwControl.Nodes.Count

lblMessage = "Click on any drive letter to load it's folders."
End Sub

Private Sub cmdEnd_Click()
Unload Me
Set Form1 = Nothing
End

End Sub

Private Sub GetSystemDrives()
Dim nodX As Node
Dim r As Long
Dim allDrives As String
Dim currDrive As String
Dim drvIcon As Integer

'get the list of all available drives

allDrives = rgbGetAvailableDrives()

Do Until allDrives = Chr$(0)

'strip off one drive item from the allDrives$

currDrive = StripNulls(allDrives)

'we can't have the trailing slash, so ..

currDrive = Left$(currDrive, 2)

'add the drive to the treeview

Set nodX = tvwControl.Nodes.Add(, tvwChild, _
currDrive & "Dir", _
currDrive)
nodX.Expanded = True

Loop

'force sorting of the drive letters

nodX.Sorted = True
End Sub

Private Function rgbGetAvailableDrives() As String
'returns a single string of available drive

'letters, each separated by a chr$(0)

Dim r As Long
Dim tmp As String

tmp = Space$(64)
r& = GetLogicalDriveStrings(Len(tmp), tmp)

rgbGetAvailableDrives = Trim$(tmp)
End Function

Private Function StripNulls(startstr As String) As String
'Take a string separated by a chr$(0), and split off 1 item, and

'shorten the string so that the next item is ready for removal.

Dim pos As Integer
Dim c As Integer
pos = InStr(startstr$, Chr$(0))

If pos Then

StripNulls = Mid$(startstr, 1, pos - 1)
startstr = Mid$(startstr, pos + 1, Len(startstr))
Exit Function

End If
End Function

Private Sub tvwControl_Click()
Dim nodX As Node

'show a wait message for long searches

lblMessage = "Searching drive " & tvwControl.SelectedItem & " for folders ... please wait"
DoEvents

'identify the selected node

Set nodX = tvwControl.SelectedItem

'verify it's valid

If (UCase$(Right$(nodX.Key, 3)) = "DIR") And (nodX.Children = 0) Then
GetAllDrivesFolders tvwControl, nodX
End If

'subtract NoOfDrives because initial drives loaded

'should not be counted as a folder

lblMessage = "Total folders displayed : " & tvwControl.Nodes.Count - NoOfDrives

End Sub

'Comment

'When the form loads, the treeview is filled with the available drives via

'the GetSystemDrives routine. Clicking a drive letter invokes the

'tvwControl_Click() routine, which calls the GetAllDrivesFolders Sub.

'The first execution of GetAllDrivesFolders returns the first-level of

'folders (try commenting out the line "GetAllDrivesFolders tvwTree, nodX"

'to demonstrate), and for each folder added to the treeview, the routine

'again calls GetAllDrivesFolders passing the node item to search from.

'Once no more folders are found (that is, there are no more folders within

'a given level), control returns to the calling line, which loads the next

'folder and restarts the process until all the first-level folders have

'been searched for sub-folders

This code is intended to demonstrate how to recursively search for all
folders on a target drive using the Win95/NT4 APIs FindFirstFile and
FindNextFile, and display the results into a treeview control.
FindFirstFile, on successful finding of a file matching the filespec passed
returns a handle for subsequent calls by FindNextFile, and the data of the
retrieved file in the WIN32_FIND_DATA structure. The structure member
dwFileAttributes, when AND'd with the VB constant vbDirectory can be used
to determine if the returned item is a file or folder. The routine stores
the folder names in an array, and once a pass is completed at each level,
creates the treeview data.
Start a new project, and to the form add a command button (cmdEnd), a
Treeview control (tvwControl) and an autosizing label (lblMessage) as
indicated in the illustration.
Place the following into the general declarations area of a bas module: