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Visual Basic
Common Dialog Routines GetOpenFileName: File Open Common Dialog Basics |
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Posted: | Friday December 27, 1996 | |
Updated: | Monday December 26, 2011 | |
Applies to: | VB4-32, VB5, VB6 | |
Developed with: | VB4-32, Windows 95 | |
Revised with: | VB6, Windows NT4 | |
OS restrictions: | None | |
Author: | VBnet - Randy Birch | |
Related: | GetOpenFileName: File Open/Save Common Dialog API - Overview GetSaveFileName: File Save Common Dialog Basics GetOpenFileName: File Dialog Centering using a Callback GetOpenFileName: Advanced Dialog Centering using a Callback GetOpenFileName: Customize File Open/Save Common Dialog Controls |
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Prerequisites |
None. |
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This
page provides the detailed code and descriptions required for the Common Dialog GetOpenFileName API, as well as showing how to retrieve the
constituent parts of the file string returned.
Code comments are at a minimum here. For detailed descriptions of the OPENFILENAME structure used and the dialog flags, see the overview listed above. Special note on NULLS: these calls require that vbNullChar (or Chr$(0)) be used as null separators or null string terminators. These APIs will not work on NT if vbNullString is used. For a discussion on modifying the OPENFILENAME structure in order to display the new Windows 2000 or Windows XP-style Open and Save dialogs, please see the comments section in the page GetOpenFileName: File Dialog Centering using a Callback (note: a hook is not required to display this new-style dialog - it just so happens that page is the one I chose to explain this on.) |
BAS Module Code |
Place the following code into the general declarations area of a bas module: |
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Option Explicit '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Copyright ©1996-2011 VBnet/Randy Birch, All Rights Reserved. ' Some pages may also contain other copyrights by the author. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ' Distribution: You can freely use this code in your own ' applications, but you may not reproduce ' or publish this code on any web site, ' online service, or distribute as source ' on any media without express permission. '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' Public Const OFN_ALLOWMULTISELECT As Long = &H200 Public Const OFN_CREATEPROMPT As Long = &H2000 Public Const OFN_ENABLEHOOK As Long = &H20 Public Const OFN_ENABLETEMPLATE As Long = &H40 Public Const OFN_ENABLETEMPLATEHANDLE As Long = &H80 Public Const OFN_EXPLORER As Long = &H80000 Public Const OFN_EXTENSIONDIFFERENT As Long = &H400 Public Const OFN_FILEMUSTEXIST As Long = &H1000 Public Const OFN_HIDEREADONLY As Long = &H4 Public Const OFN_LONGNAMES As Long = &H200000 Public Const OFN_NOCHANGEDIR As Long = &H8 Public Const OFN_NODEREFERENCELINKS As Long = &H100000 Public Const OFN_NOLONGNAMES As Long = &H40000 Public Const OFN_NONETWORKBUTTON As Long = &H20000 Public Const OFN_NOREADONLYRETURN As Long = &H8000& 'see comments Public Const OFN_NOTESTFILECREATE As Long = &H10000 Public Const OFN_NOVALIDATE As Long = &H100 Public Const OFN_OVERWRITEPROMPT As Long = &H2 Public Const OFN_PATHMUSTEXIST As Long = &H800 Public Const OFN_READONLY As Long = &H1 Public Const OFN_SHAREAWARE As Long = &H4000 Public Const OFN_SHAREFALLTHROUGH As Long = 2 Public Const OFN_SHAREWARN As Long = 0 Public Const OFN_SHARENOWARN As Long = 1 Public Const OFN_SHOWHELP As Long = &H10 Public Const OFS_MAXPATHNAME As Long = 260 'OFS_FILE_OPEN_FLAGS and OFS_FILE_SAVE_FLAGS below 'are mine to save long statements; they're not 'a standard Win32 type. Public Const OFS_FILE_OPEN_FLAGS = OFN_EXPLORER _ Or OFN_LONGNAMES _ Or OFN_CREATEPROMPT _ Or OFN_NODEREFERENCELINKS Public Const OFS_FILE_SAVE_FLAGS = OFN_EXPLORER _ Or OFN_LONGNAMES _ Or OFN_OVERWRITEPROMPT _ Or OFN_HIDEREADONLY Public Type OPENFILENAME nStructSize As Long hWndOwner As Long hInstance As Long sFilter As String sCustomFilter As String nMaxCustFilter As Long nFilterIndex As Long sFile As String nMaxFile As Long sFileTitle As String nMaxTitle As Long sInitialDir As String sDialogTitle As String flags As Long nFileOffset As Integer nFileExtension As Integer sDefFileExt As String nCustData As Long fnHook As Long sTemplateName As String End Type Public OFN As OPENFILENAME Public Declare Function GetOpenFileName Lib "comdlg32" _ Alias "GetOpenFileNameA" _ (pOpenfilename As OPENFILENAME) As Long Public Declare Function GetSaveFileName Lib "comdlg32" _ Alias "GetSaveFileNameA" _ (pOpenfilename As OPENFILENAME) As Long Public Declare Function GetShortPathName Lib "kernel32" _ Alias "GetShortPathNameA" _ (ByVal lpszLongPath As String, _ ByVal lpszShortPath As String, _ ByVal cchBuffer As Long) As Long |
Form Code |
To a new project form add a command button (Command1), seven Text boxes (Text1-Text7), a List (List1) and a Checkbox (Check1). The text boxes are oriented beginning with the first label/textbox as Text/Label #1, the next #2 and so on. Add the following code to the form: |
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Option Explicit Private Sub Command1_Click() 'used in call setup Dim sFilters As String 'used after call Dim pos As Long Dim buff As String Dim sLongname As String Dim sShortname As String 'create a string of filters for the dialog sFilters = "Visual Basic Forms" & vbNullChar & "*.frm" & vbNullChar & _ "Visual Basic Modules" & vbNullChar & "*.bas" & vbNullChar & _ "Visual Basic Projects" & vbNullChar & "*.vbp" & vbNullChar & _ "Text Files" & vbNullChar & "*.txt" & vbNullChar & _ "All Files" & vbNullChar & "*.*" & vbNullChar & vbNullChar With OFN 'size of the OFN structure .nStructSize = Len(OFN) 'window owning the dialog .hWndOwner = Form1.hWnd 'filters (patterns) for the dropdown combo .sFilter = sFilters 'index to the initial filter .nFilterIndex = 2 'default filename, plus additional padding 'for the user's final selection(s). Must be 'double-null terminated .sFile = "Untitled.bas" & Space$(1024) & vbNullChar & vbNullChar 'the size of the buffer .nMaxFile = Len(.sFile) 'default extension applied to 'file if it has no extention .sDefFileExt = "bas" & vbNullChar & vbNullChar 'space for the file title if a single selection 'made, double-null terminated, and its size .sFileTitle = vbNullChar & Space$(512) & vbNullChar & vbNullChar .nMaxTitle = Len(OFN.sFileTitle) 'starting folder, double-null terminated .sInitialDir = "d:\vb5" & vbNullChar & vbNullChar 'the dialog title .sDialogTitle = "VBnet GetOpenFileName Demo" 'default open flags and multiselect .flags = OFS_FILE_OPEN_FLAGS Or _ OFN_ALLOWMULTISELECT End With 'call the API If GetOpenFileName(OFN) Then 'remove trailing pair of terminating nulls 'and trim returned file string buff = Trim$(Left$(OFN.sFile, Len(OFN.sFile) - 2)) 'show the members of the returned sFile 'string in the listbox. If multiselect, 'the first member is the path, and the 'remaining members are the files under 'that path selected. Do While Len(buff) > 3 List1.AddItem StripDelimitedItem(buff, vbNullChar) Loop 'see illustration for descriptions Text1.Text = OFN.sFile Text2.Text = Left$(OFN.sFile, OFN.nFileOffset) Text3.Text = Mid$(OFN.sFile, OFN.nFileOffset + 1, _ Len(OFN.sFile) - OFN.nFileOffset - 1) 'note the extention and filetitle are not 'returned in when in multiselect mode Text4.Text = Mid$(OFN.sFile, OFN.nFileExtension + 1, _ Len(OFN.sFile) - OFN.nFileExtension) Text5.Text = OFN.sFileTitle sLongname = OFN.sFileTitle sShortname = Space$(128) pos = GetShortPathName(sLongname, sShortname, Len(sShortname)) Text6.Text = LCase$(Left$(sShortname, pos)) sLongname = OFN.sFile sShortname = Space$(128) pos = GetShortPathName(sLongname, sShortname, Len(sShortname)) Text7.Text = LCase$(Left$(sShortname, pos)) Check1.Value = Abs((OFN.flags And OFN_READONLY)) End If End Sub Private Function StripDelimitedItem(startStrg As String, _ delimiter As String) As String 'take a string separated by nulls, 'split off 1 item, and shorten the string 'so the next item is ready for removal. Dim pos As Long Dim item As String pos = InStr(1, startStrg, delimiter) If pos Then StripDelimitedItem = Mid$(startStrg, 1, pos) startStrg = Mid$(startStrg, pos + 1, Len(startStrg)) End If End Function Private Function TrimNull(item As String) As String Dim pos As Integer pos = InStr(item, Chr$(0)) If pos Then TrimNull = Left$(item, pos - 1) Else TrimNull = item End If End Function |
Comments |
Once the displayed dialog has closed, the file details for
the selected or new file(s) will be returned on the form.
For a discussion on modifying the OPENFILENAME structure in order to display the new Windows 2000 or Windows XP-style Open and Save dialogs, please see the comments section in the page GetOpenFileName: File Dialog Centering using a Callback (note: a hook is not required to display this new-style dialog - it just so happens that page is the one I chose to explain this on.) Note: re OFN_NOREADONLYRETURN: This value is define in the header files as &H8000, which unfortunately is -32768 in VB. The correct value required 32768, so an ampersand (&) must be appended to this value to force VB to cast this to a Long. This is even true if the constant is defined As Long in the declare. If you use this constant in your apps and the file dialog either does not appear or the app crashes without an error, check this value. |
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Copyright ©1996-2011 VBnet and Randy Birch. All Rights Reserved. |