Knowledge Base

BUG: Drag From FileListBox Includes Extra Backslash

Article ID: 183906

Article Last Modified on 5/12/2003

Microsoft Visual Basic 5.0 Learning Edition
Microsoft Visual Basic 6.0 Learning Edition
Microsoft Visual Basic 5.0 Professional Edition
Microsoft Visual Basic 6.0 Professional Edition
Microsoft Visual Basic 5.0 Enterprise Edition
Microsoft Visual Basic 6.0 Enterprise Edition

This article was previously published under Q183906

SYMPTOMS

If a file is dragged from the FileListBox control, and that file is located in the root directory, Visual Basic includes an extra backslash (\) in the file path. This may cause one of the following errors on Windows 95, Windows 98, or Windows Me:

Cannot copy file. File System Error (1026)

-or-

Cannot copy <filename>. Cannot find the specified file. Make sure you specify the correct path and filename.

While no error occurs under Windows NT or Windows 2000, the erroneous backslash is still present.

RESOLUTION

As a workaround, add the following code to your form. The code will intercept the Drag operation and remove the extra backslash character. This code assumes that the name of the FileListBox is File1:

      Private Sub File1_OLEStartDrag(Data As DataObject, _
                                         AllowedEffects As Long)
      Dim FileNames As New Collection
      Dim vFn As Variant

      'Retrieve current set of files from the file control
      For Each vFn In Data.Files
         FileNames.Add vFn
      Next vFn

      'Clear the list in the data object, and add the corrected files back
      Data.Files.Clear
      For Each vFn In FileNames
         Data.Files.Add RemoveExtraBackslash(vFn)
      Next vFn
   End Sub

   Private Function RemoveExtraBackslash(ByVal str$) As String
      While True
         Dim i%
         i = InStr(str, "\\")
         If i > 0 Then
            str = Left$(str, i - 1) & Mid$(str, i + 1)
         Else
            RemoveExtraBackslash = str
            Exit Function
        End If
      Wend
   End Function

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this bug and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Behavior

Start a new Standard EXE project in Visual Basic. Form1 is created by default.
Add a FileListBox and a DirListBox to Form1.

Add the following code to Form1:

      Private Sub Dir1_Change()
         File1.Path = Dir1.Path
      End Sub

Change OLEDragMode property of the FileListBox to 1-Automatic.
Start the program and change the path of the DirListBox to C:\.
Start Windows Explorer.
If you are running Windows 95, Windows 98, or Windows Me, drag one of the files from the FileListBox to any directory in Windows Explorer. You should see an error dialog as described earlier.
Drag one of the files from the FileListBox to the Start...Run dialog window. You should see the incorrect path with the extra backslash.
Copy the workaround code from the RESOLUTION section into your project and run it again. Drag one of the files from the FileListBox to the Start...Run dialog window. You should see the correct path displayed.

Additional query words: back slash listbox file list box

Keywords: kbbug kbctrl kbpending kbcontrol KB183906