Binaryworld - ShowOpenFileDialog - Show a Open File common dialog ... [ VB -> Dialogbox ]

Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias _
  "GetOpenFileNameA" (pOpenfilename As OpenFilename) As Long

Private Type OpenFilename
  lStructSize As Long
  hwndOwner As Long
  hInstance As Long
  lpstrFilter As String
  lpstrCustomFilter As String
  nMaxCustFilter As Long
  iFilterIndex As Long
  lpstrFile As String
  nMaxFile As Long
  lpstrFileTitle As String
  nMaxFileTitle As Long
  lpstrInitialDir As String
  lpstrTitle As String
  flags As Long
  nFileOffset As Integer
  nFileExtension As Integer
  lpstrDefExt As String
  lCustData As Long
  lpfnHook As Long
  lpTemplateName As String
End Type

Private Enum OFNFlagsEnum
  OFN_ALLOWMULTISELECT = &H200
  OFN_CREATEPROMPT = &H2000
  OFN_ENABLEHOOK = &H20
  OFN_ENABLETEMPLATE = &H40
  OFN_ENABLETEMPLATEHANDLE = &H80
  OFN_EXPLORER = &H80000
  OFN_EXTENSIONDIFFERENT = &H400
  OFN_FILEMUSTEXIST = &H1000
  OFN_HIDEREADONLY = &H4
  OFN_LONGNAMES = &H200000
  OFN_NOCHANGEDIR = &H8
  OFN_NODEREFERENCELINKS = &H100000
  OFN_NOLONGNAMES = &H40000
  OFN_NONETWORKBUTTON = &H20000
  OFN_NOREADONLYRETURN = &H8000
  OFN_NOTESTFILECREATE = &H10000
  OFN_NOVALIDATE = &H100
  OFN_OVERWRITEPROMPT = &H2
  OFN_PATHMUSTEXIST = &H800
  OFN_READONLY = &H1
  OFN_SHAREAWARE = &H4000
  OFN_SHAREFALLTHROUGH = 2
  OFN_SHARENOWARN = 1
  OFN_SHAREWARN = 0
  OFN_SHOWHELP = &H10
End Enum

' Show the common dialog to select a file to open. Returns the path of the
' selected file or a null string if the dialog is canceled
' Parameters:
' - sFilter is used to specify what type(s) of files will be shown
' - sDefExt is the default extension associated to a file name if no one is
' specified by the user
' - sInitDir is the directory that will be open when the dialog is shown
' - lFlag is a combination of Flags for the dialog. Look at the Common
' Dialogs' Help for more informations
' - hParent is the handle of the parent form

' Example:
'  Dim sFilter As String
'  'set the filter: show text files and all the files
'  sFilter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"
'  'let the user select a file, ensuring that it exists
'  MsgBox "File selected: " & ShowOpenFileDialog(sFilter, "txt",
' "C:\Documents", OFN_FILEMUSTEXIST)

Function ShowOpenFileDialog(ByVal sFilter As String, Optional ByVal sDefExt As _
  String, Optional ByVal sInitDir As String, Optional ByVal lFlags As Long, _
  Optional ByVal hParent As Long) As String
  Dim OFN As OpenFilename
  On Error Resume Next

  ' set the values for the OpenFileName struct
  With OFN
    .lStructSize = Len(OFN)
    .hwndOwner = hParent
    .lpstrFilter = Replace(sFilter, "|", vbNullChar) & vbNullChar
    .lpstrFile = Space$(255) & vbNullChar & vbNullChar
    .nMaxFile = Len(.lpstrFile)
    .flags = lFlags
    .lpstrInitialDir = sInitDir
    .lpstrDefExt = sDefExt
  End With

  ' show the dialog, non-zero means success
  If GetOpenFileName(OFN) Then
    ' extract the selected file (including the path)
    ShowOpenFileDialog = Left$(OFN.lpstrFile, InStr(OFN.lpstrFile, _
      vbNullChar) - 1)
  End If
End Function

Private Sub Form_Load()
  Dim sFilter
  sFilter = "Text files (*.txt)|*.txt|All files (*.*)|*.*"
  MsgBox "File selected: " & ShowOpenFileDialog(sFilter, "txt", "C:\Documents", OFN_OVERWRITEPROMPT)
End Sub