DOCUMENT:Q198974  11-JAN-2001  [vbwin]
TITLE   :HOWTO: Use the Common Dialog Control with Multiple Long File Nam
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0,6.0
OPER/SYS:
KEYWORDS:kbCmnDlg kbCmnDlgFileO kbCtrl kbVBp kbVBp500 kbVBp600 kbGrpDSVB kbDSupport

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The information in this article applies to:

 - Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0 
 - Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0 
 - Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0 
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SUMMARY
=======

The following article provides an example of retrieving more than one file using
the Common Dialog control. There are several Flag properties that can be set for
the ShowOpen method of the Common Dialog control to enable the selection of
multiple files and long file names. For example, cdlOFNAllowMultiselect +
cdlOFNExplorer provides for the selection of multiple files and an Explorer-like
dialog window. Selecting these two flags also enables long file names (LFN) and
causes the Common Dialog control to use different delimiters in the string that
it fills with file and directory information. The programming approach
demonstrated in this article is required when both long file names and multiple
files are enabled as a result of flag selection.

Microsoft Visual Basic Books Online indicates that when these two flags are used,
it is necessary to code differently when using Microsoft Windows 95 and
Microsoft Windows NT. This is incorrect. The same code works in both
environments.

MORE INFORMATION
================

When long file names are not enabled, the Common Dialog control uses a space to
separate the file names when multiple files have been selected. This delimiter
cannot be used with long file names, which may contain spaces. When both long
file names and multiple file selections are enabled, the Common Dialog control
uses a null character to delimit the file names.

Additionally, the Common Dialog control delimits the string differently when only
one file is selected. For example, the string is constructed in the following
way if only one file is selected:

   c:\my files\my file.txt

When more than one file is selected, the string looks like this:

   c:\my files<null>my file.txt<null>my file.rtf

The example below demonstrates how to extract the information from this string
when both Long File Names and Multiple File Selection are enabled through flag
selections.

Step-by-Step Example
--------------------

1. Start a new Standard EXE project in Visual Basic. Form1 is created by
   default.

2. From the Project menu, select Components, check Microsoft Common Dialog
   Control, and click OK.

3. Add a Common Dialog control, two TextBoxes, and a CommandButton to Form1.

4. Make Text2 fairly tall, set the MultiLine property to True, and set the
   Scrollbars property to "2 - vertical."

5. Put the following code in the form's module:

        '*** Start Code ****
       Option Explicit

      Private Sub Command1_Click()
      Dim current As Integer
      Dim I As Integer
      Dim intIndex As Integer
      Dim iStart As Integer
      Dim FileNames$()
      Dim sFname As String
      Dim iEndPath As Integer

      Text2.Text = ""
      With CommonDialog1
         .MaxFileSize = 2048   ' Set as appropriate
         .filename = ""
         .Filter = "All Files|*.*"
         .Flags = cdlOFNAllowMultiselect + cdlOFNExplorer
         .ShowOpen
         sFname = .filename & vbNullChar
      End With

      iEndPath = 1
      ' determine if multiple files were selected
      ' null delimiter is not inserted if only 1 file is selected
      If countDelimiters(sFname, vbNullChar) = 1 Then
         Do Until (iEndPath = 0)
            iStart = iEndPath + 1
            iEndPath = InStr(iEndPath + 1, sFname, "\")
         Loop
         ReDim Preserve FileNames(0)
         ' determine if root directory was selected - preserve the "\"
         If countDelimiters(sFname, "\") = 1 Then
            FileNames(0) = Mid(sFname, 1, iStart - 1)
         Else
            FileNames(0) = Mid(sFname, 1, iStart - 2)
         End If
      Else
         iStart = InStr(1, sFname, vbNullChar) + 1
         ReDim Preserve FileNames(0)
         FileNames(0) = Left(sFname, iStart - 2)
      End If

      intIndex = 1
      For I = iStart To Len(sFname)
         If Mid(sFname, I, 1) = vbNullChar Then
           ReDim Preserve FileNames(intIndex)
           FileNames(intIndex) = Mid(sFname, iStart, I - iStart)
           iStart = I + 1
           intIndex = intIndex + 1
         End If
      Next I

      ' display information in proper text box
      For I = 0 To UBound(FileNames)
         If I Then
            Text2.Text = Text2.Text & FileNames(I) & vbCrLf
         Else
            Text1.Text = FileNames(I)
         End If
      Next I

      End Sub

      Function countDelimiters(ByVal sFiles As String, _
         ByVal vSearchChar As Variant) As Integer

       Dim iCtr As Integer
       Dim iResult As Integer

       For iCtr = 1 To Len(sFiles)
           If Mid(sFiles, iCtr, 1) = vSearchChar Then iResult = iResult + 1
       Next iCtr

       countDelimiters = iResult

      End Function
      '*** End Code ***

6. Run the sample. The folder is listed in Text1 and the files are listed in
   Text2.

NOTE: This coding example contains no error handling. Microsoft recommends that
you provide a means of dealing with potential errors before using this example
in a production system.

Additional query words: cdlOFNLongNames

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Keywords          : kbCmnDlg kbCmnDlgFileO kbCtrl kbVBp kbVBp500 kbVBp600 kbGrpDSVB kbDSupport 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600
Version           : WINDOWS:5.0,6.0
Issue type        : kbhowto

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