Library code snippets
Display the Open Dialog
By James Crowley, published on 14 Jul 2001
James first started this website when learning Visual Basic back in 1999 whilst studying his GCSEs. The site grew steadily over the years while being run as a hobby - to a regular monthly audience ...
James first started this website when learning Visual Basic back in 1999 whilst studying his GCSEs. The site grew steadily over the years while being run as a hobby - to a regular monthly audience ...
The Common Dialog control is one of those things that never should have been a control, just like the Timer. Well, now you don't have to use it at all. You can just call the CmDlg.dll instead (which you do not need to distribute - it is a standard windows dll). Despite the length of the code, it is still much smaller than the Common Dialog control, and you get more flexibility.
'Module Code
Option Explicit
'// type that passes/returns value through ShowOpenDialog function
Public Type stcFileStruct
strFileName As String
strFileTitle As String
strFilter As String
strDialogtitle As String
lngFilterIndex As Long
blnReadOnly As Boolean
End Type
'// Max filename and path constants
Const cMaxPath = 260
Const cMaxFile = 260
'// Open File name type
Private Type OPENFILENAME
lStructSize As Long
' Filled with UDT size
hwndOwner As Long
' Tied to Owner
hInstance As Long
' Ignored (used only by templates)
lpstrFilter As String
' Tied to Filter
lpstrCustomFilter As String ' Ignored
nMaxCustFilter As Long
' Ignored
nFilterIndex As Long
' Tied to FilterIndex
lpstrFile As String
' Tied to FileName
nMaxFile As Long
' Handled internally
lpstrFileTitle As String ' Tied to
FileTitle
nMaxFileTitle As Long
' Handled internally
lpstrInitialDir As String ' Tied to InitDir
lpstrTitle As String
' Tied to DlgTitle
Flags As Long
' Tied to Flags
nFileOffset As Integer
' Ignored
nFileExtension As Integer ' Ignored
lpstrDefExt As String
' Tied to DefaultExt
lCustData As Long
' Ignored (needed for hooks)
lpfnHook As Long
' Ignored (good luck with hooks)
lpTemplateName As Long
' Ignored (good luck with templates)
End Type
Private Declare Function GetOpenFileName Lib "COMDLG32" _
Alias "GetOpenFileNameA" (file As OPENFILENAME)
As Long
'// flags
Public Enum EOpenFile
OFN_READONLY = &H1
OFN_OVERWRITEPROMPT = &H2
OFN_HIDEREADONLY = &H4
OFN_NOCHANGEDIR = &H8
OFN_SHOWHELP = &H10
OFN_ENABLEHOOK = &H20
OFN_ENABLETEMPLATE = &H40
OFN_ENABLETEMPLATEHANDLE = &H80
OFN_NOVALIDATE = &H100
OFN_ALLOWMULTISELECT = &H200
OFN_EXTENSIONDIFFERENT = &H400
OFN_PATHMUSTEXIST = &H800
OFN_FILEMUSTEXIST = &H1000
OFN_CREATEPROMPT = &H2000
OFN_SHAREAWARE = &H4000
OFN_NOREADONLYRETURN = &H8000
OFN_NOTESTFILECREATE = &H10000
OFN_NONETWORKBUTTON = &H20000
OFN_NOLONGNAMES = &H40000
OFN_EXPLORER = &H80000
OFN_NODEREFERENCELINKS = &H100000
OFN_LONGNAMES = &H200000
End Enum
'// Main function
Function VBGetOpenFileName(FileName As String, _
Optional FileTitle As String, _
Optional FileMustExist As Boolean = True, _
Optional MultiSelect As Boolean = False, _
Optional ReadOnly As Boolean = False, _
Optional HideReadOnly As Boolean = False, _
Optional filter As String = "All (*.*)| *.*", _
Optional FilterIndex As Long = 1, _
Optional InitDir As String, _
Optional DlgTitle As String, _
Optional DefaultExt As String, _
Optional Owner As Long = -1, _
Optional Flags As Long = 0) As Boolean
Dim opfile As OPENFILENAME, s As String, afFlags As Long
With opfile
.lStructSize = Len(opfile)
' Add in specific flags and strip out non-VB flags
.Flags = (-FileMustExist * OFN_FILEMUSTEXIST) Or _
(-MultiSelect
* OFN_ALLOWMULTISELECT) Or _
(-ReadOnly
* OFN_READONLY) Or _
(-HideReadOnly
* OFN_HIDEREADONLY) Or _
(Flags
And CLng(Not (OFN_ENABLEHOOK Or _
OFN_ENABLETEMPLATE)))
' Owner can take handle of owning window
If Owner <> -1 Then .hwndOwner = Owner
' InitDir can take initial directory string
.lpstrInitialDir = InitDir
' DefaultExt can take default extension
.lpstrDefExt = DefaultExt
' DlgTitle can take dialog box title
.lpstrTitle = DlgTitle
' To make Windows-style filter, replace | and : with nulls
Dim ch As String, i As Integer
For i = 1 To Len(filter)
ch = Mid$(filter, i, 1)
If ch = "|" Or ch = ":"
Then
s = s &
vbNullChar
Else
s = s &
ch
End If
Next
' Put double null at end
s = s & vbNullChar & vbNullChar
.lpstrFilter = s
.nFilterIndex = FilterIndex
' Pad file and file title buffers to maximum path
s = FileName & String$(cMaxPath - Len(FileName), 0)
.lpstrFile = s
.nMaxFile = cMaxPath
s = FileTitle & String$(cMaxFile - Len(FileTitle), 0)
.lpstrFileTitle = s
.nMaxFileTitle = cMaxFile
' All other fields set to zero
If GetOpenFileName(opfile) Then
VBGetOpenFileName = True
FileName = StrZToStr(.lpstrFile)
FileTitle = StrZToStr(.lpstrFileTitle)
Flags = .Flags
' Return the filter index
FilterIndex = .nFilterIndex
' Look up the filter the user selected
and return that
filter = FilterLookup(.lpstrFilter,
FilterIndex)
If (.Flags And OFN_READONLY) Then
ReadOnly = True
Else
VBGetOpenFileName = False
FileName = Empty
FileTitle = Empty
Flags = 0
FilterIndex = -1
filter = Empty
End If
End With
End Function
'// convert the filter to standard required by windows api
Private Function FilterLookup(ByVal sFilters As String, ByVal iCur As Long)
As String
Dim iStart As Long, iEnd As Long, s As String
iStart = 1
If sFilters = Empty Then Exit Function
Do
' Cut out both parts marked by null
character
iEnd = InStr(iStart, sFilters, vbNullChar)
If iEnd = 0 Then Exit Function
iEnd = InStr(iEnd + 1, sFilters,
vbNullChar)
If iEnd Then
s = Mid$(sFilters,
iStart, iEnd - iStart)
Else
s = Mid$(sFilters,
iStart)
End If
iStart = iEnd + 1
If iCur = 1 Then
FilterLookup
= s
Exit Function
End If
iCur = iCur - 1
Loop While iCur
End Function
'// show open dialog function (pass/return filestruct)
Public Function ShowOpenDialog(filestruct As stcFileStruct) As Boolean
With filestruct
If .strFilter = Empty Then .strFilter
= "All Files|*.*"
ShowOpenDialog = VBGetOpenFileName(.strFileName,
.strFileTitle,
True, , .blnReadOnly, , .strFilter, .lngFilterIndex, , .strDialogtitle)
End With
StripFileStruct filestruct '// Return FileStruct
End Function
'// Removes nulls from the two strings in stcFileStruct
Private Sub StripFileStruct(filestruct As stcFileStruct)
With filestruct
.strFileName = StripTerminator(.strFileName)
.strFileTitle = StripTerminator(.strFileTitle)
End With
End Sub
'// Removes trailing nulls from a string
Function StripTerminator(ByVal strString As String) As String
Dim intZeroPos As Integer
intZeroPos = InStr(strString, Chr$(0))
If intZeroPos > 0 Then
StripTerminator = Left$(strString,
intZeroPos - 1)
Else
StripTerminator = strString
End If
End Function
Function StrZToStr(s As String) As String
StrZToStr = Left$(s, Len(s))
End Function
'Form Code
Private Sub cmdOpen_Click()
Dim File As stcFileStruct
'// fill values (not required)
File.strDialogtitle = "Select file to open"
File.strFilter = "Text Files *.txt|*.txt" '// use
same format as
commondialog control
'// pass stcFileStruct
ShowOpenDialog File
'// get return values (passed back through type)
With File
Msgbox "FileName: " &
.strFileName
Msgbox "ReadOnly: " &
.blnReadOnly
Msgbox "FileTitle: " &
.strFileTitle
Msgbox "Filter Index: "
& .lngFilterIndex
End With
End Sub
Related articles
Related discussion
-
Visual Studio: MDI Parent Form designer
by cutiegigshorty (0 replies)
-
Working on Who Wants To Be A Millionaire Project in VB6 [NEED HELP]
by candienne092 (2 replies)
-
Needs help with MSFlexGrid and MSAccess in VB6
by ClarkKentNeedsHelp (0 replies)
-
Make me or point me to an installer with comctl32 vb6
by tgkprog2 (0 replies)
-
How to use VB6 to make cumulative frequency polygons
by heibaidoufu (0 replies)
How do we show the Save dialog? It's not much use without that...
This thread is for discussions of Display the Open Dialog.