FredixBlog

This function is a call to the ‘Open File’ dialog box.
For instance, if you call the function from a button in a form, your call will look like this:

sFilename = gsWinDlgOpen((Me.Hwnd), \”Title of the window\”, \”MyFile.txt\” & Chr$(0) & \”MyFile.txt\” & Chr$(0), \”C:\\\”)

The declaration should be:

Declare Function GetOpenFileNameA Lib \”COMDLG32.DLL\” (tFilename As CMDLG_FILENAME) As Integer

Public Function GetOpenFileName(tFilename As CMDLG_FILENAME) As Integer
  GetOpenFileName = GetOpenFileNameA(tFilename)
End Function
Type CMDLG_FILENAME
    lStructSize As Long
    hWndOwner As Long
    hInstance As Long
    lpstrsFilter As String
    lpstrCustomsFilter As String
    nMaxCustsFilter As Long
    nsFilterIndex 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

Declare Function GetOpenFileNameA Lib “COMDLG32.DLL” (tFilename As CMDLG_FILENAME) As Integer

Public Function GetOpenFileName(tFilename As CMDLG_FILENAME) As Integer
   GetOpenFileName = GetOpenFileNameA(tFilename)
End Function

Const CMDLG_OFN_READONLY = &H1
Const CMDLG_OFN_OVERWRITEPROMPT = &H2
Const CMDLG_OFN_HIDEREADONLY = &H4
Const CMDLG_OFN_NOCHANGEDIR = &H8
Const CMDLG_OFN_SHOWHELP = &H10
Const CMDLG_OFN_ENABLEHOOK = &H20
Const CMDLG_OFN_ENABLETEMPLATE = &H40
Const CMDLG_OFN_ENABLETEMPLATEHANDLE = &H80
Const CMDLG_OFN_NOVALIDATE = &H100
Const CMDLG_OFN_ALLOWMULTISELECT = &H200
Const CMDLG_OFN_EXTENSIONDIFFERENT = &H400
Const CMDLG_OFN_PATHMUSTEXIST = &H800
Const CMDLG_OFN_FILEMUSTEXIST = &H1000
Const CMDLG_OFN_CREATEPROMPT = &H2000
Const CMDLG_OFN_SHAREAWARE = &H4000
Const CMDLG_OFN_NOREADONLYRETURN = &H8000
Const CMDLG_OFN_NOTESTFILECREATE = &H10000

Const CMDLG_OFN_SHAREFALLTHROUGH = 2
Const CMDLG_OFN_SHARENOWARN = 1
Const CMDLG_OFN_SHAREWARN = 0

Function gsWinDlgOpen(hWnd As Long, sTitel As String, sFilter As String, sCurDir As String) As String

   Dim tFilename As CMDLG_FILENAME
   Dim sFilename As String
   Dim sFiletitel As String
   Dim sDefExt As String

   sTitel = sTitel + Chr$(0)
   sFilter = sFilter & “Alle Dateien (*.*)” & Chr$(0) & “*.*” & Chr$(0) & Chr$(0)
   sFilename = Chr$(0) & Space$(255) & Chr$(0)
   sFiletitel = Chr$(0) & Space$(255) & Chr$(0)
   sDefExt = Chr$(0)
   sCurDir = gvntNull2Arg(sCurDir, CurDir$) & Chr$(0)

   tFilename.lStructSize = Len(tFilename)
   tFilename.hWndOwner = hWnd
   tFilename.lpstrsFilter = sFilter
   tFilename.nsFilterIndex = 1
   tFilename.lpstrFile = sFilename
   tFilename.nMaxFile = Len(sFilename)
   tFilename.lpstrFileTitle = sFiletitel
   tFilename.nMaxFileTitle = Len(sFiletitel)
   tFilename.lpstrTitle = sTitel
   tFilename.Flags = CMDLG_OFN_FILEMUSTEXIST Or CMDLG_OFN_HIDEREADONLY
   tFilename.lpstrInitialDir = sCurDir

   If GetOpenFileName(tFilename) <> 0 Then
       gsWinDlgOpen = gsTrim(tFilename.lpstrFile)
   Else
       gsWinDlgOpen = “”
   End If

End Function
Function gsTrim(s As String) As String

   gsTrim = Trim$(Left$(s, InStr(1, s & Chr$(0), Chr$(0), 0) - 1))

End Function

Function gvntNull2Arg(vntExp As Variant, vntPara As Variant) As Variant

   If gbNull(vntExp) Then
       gvntNull2Arg = vntPara
   Else
       gvntNull2Arg = vntExp
   End If
   
End Function

Function gbNull(vnt As Variant) As Integer

   On Error GoTo gbNullError

   Select Case VarType(vnt)
   Case V_NULL, V_EMPT
       gbNull = True
   Case V_STRING
       gbNull = (Len(gsTrim(CStr(vnt))) = 0)
   Case V_DATE
       gbNull = False
   Case Else
       gbNull = (vnt = 0)
   End Select

gbNullExit:
   Exit Function

gbNullError:
   gbNull = True
   Resume gbNullExit

End Function