cDialog class

Shows the Windows Open, Save As and Browse For Folder dialogs, builds the file-type list of the first two, takes file paths apart, and opens a file in the program that Windows associates with it.

Properties set the options of a dialog before it is shown. ShowOpen, ShowSave and ShowBrowseForFolder show the dialogs and return the path that the user chose. A cancelled dialog returns an empty string. ShowOpen and ShowSave also store the path in FileName.

Dim dlg As New cDialog
Dim path As String

dlg.DialogTitle = "Open a text file"
dlg.SetCommonFilters
path = dlg.ShowOpen()

If Len(path) > 0 Then
    Debug.Print "Chosen: " & path
    Debug.Print "Name: " & dlg.GetFileName(path)
End If

The options are the members and flags of the Win32 structures that the dialogs take: OPENFILENAME for ShowOpen (GetOpenFileNameW) and ShowSave (GetSaveFileNameW), and BROWSEINFO for ShowBrowseForFolder (SHBrowseForFolder). Each property page names the flag it sets and the dialogs in which it takes effect, and the table below lists them all.

Note

The property names follow VB6’s CommonDialog control, but cDialog is a class with a smaller set of members. It has no Flags property (each option is a Boolean property of its own), no FilterIndex (the first filter is always selected, and the filter that the user chose is not reported), no CancelError (a cancelled dialog returns an empty string), no FileTitle or MaxFileSize, and no owner window. InitialDir is the control’s InitDir. ShowOpen returns the file name, as well as storing it in FileName, and there is no Color, Font or Print dialog. The CommonDialog class of the VBComDlg package has Flags, FilterIndex, CancelError, FileTitle, MaxFileSize and those dialogs.

Warning

ShowBrowseForFolder works in 32-bit programs only. In a 64-bit program it ends the program with an access violation before any dialog appears, because the class declares the handles, pointers and item list of that dialog as Long.

Warning

With MultiSelect True and several files selected, ShowOpen returns only the folder of the files, as a String, and the names of the files are lost. No error is raised.

Defaults

A new cDialog starts with these values, and Reset restores them.

Property	Starting value
DialogTitle, InitialDir, DefaultExt, FileName, Filter	An empty string
MultiSelect, ReadOnly, NoChangeDir, CreatePrompt	False
OverwritePrompt, PathMustExist, FileMustExist, HideReadOnly, NewDialogStyle	True

Dim dlg As New cDialog
Debug.Print dlg.MultiSelect      ' False
Debug.Print dlg.FileMustExist    ' True
Debug.Print dlg.NewDialogStyle   ' True
Debug.Print Len(dlg.Filter)      ' 0

Which dialog uses which property

yes means that the class passes the value to Windows for that dialog. A property marked ignored is stored and returned, and the dialog does not receive it. ShowOpen and ShowSave read and write FileName; ShowBrowseForFolder writes InitialDir when the user chooses a folder, and does not read it.

Property	Win32 member or flag	ShowOpen	ShowSave	ShowBrowseForFolder
DialogTitle	`lpstrTitle`, `lpszTitle`	yes	yes	yes
InitialDir	`lpstrInitialDir`	yes	yes	written, not read
DefaultExt	`lpstrDefExt`	yes	yes	ignored
FileName	`lpstrFile`	read and written	read and written	ignored
Filter	`lpstrFilter`	yes	yes	ignored
MultiSelect	`OFN_ALLOWMULTISELECT`	yes	ignored	ignored
OverwritePrompt	`OFN_OVERWRITEPROMPT`	yes	yes	ignored
PathMustExist	`OFN_PATHMUSTEXIST`	yes	yes	ignored
FileMustExist	`OFN_FILEMUSTEXIST`	yes	ignored	ignored
HideReadOnly	`OFN_HIDEREADONLY`	yes	yes	ignored
ReadOnly	`OFN_READONLY`	yes	ignored	ignored
NoChangeDir	`OFN_NOCHANGEDIR`	yes	yes	ignored
CreatePrompt	`OFN_CREATEPROMPT`	yes	ignored	ignored
NewDialogStyle	`BIF_USENEWUI`	ignored	ignored	yes

Windows documents some of these flags for one kind of dialog only. OFN_OVERWRITEPROMPT is documented for Save As, and OFN_FILEMUSTEXIST for Open. The class passes OverwritePrompt to ShowOpen all the same.

Settings without a property

Some settings cannot be changed.

ShowOpen and ShowSave always set OFN_LONGNAMES, OFN_EXPLORER and OFN_ENABLESIZING. Windows documents the effect of OFN_LONGNAMES and OFN_ENABLESIZING for old-style dialogs, hooks and templates, none of which the class uses. OFN_EXPLORER selects the layout of the buffer that a multiple selection returns (MultiSelect).
ShowOpen and ShowSave always select the first pair of the Filter list (nFilterIndex is 1) and do not report the pair that the user chose.
ShowOpen and ShowSave pass no hook procedure, no custom template and no custom filter. The flags that the dialog returns are not read, so the choice of Open as read-only (see HideReadOnly) is not available after the dialog closes.
ShowBrowseForFolder always sets BIF_RETURNONLYFSDIRS, so only a folder of the file system can be chosen, and passes no root folder and no callback.
No dialog has an owner window: the class passes 0 for hwndOwner in both structures.

Properties

CreatePrompt – asks before the Open dialog accepts a file that does not exist
DefaultExt – the extension that Windows adds to a file name typed without one
DialogTitle – the text that the dialogs show as their title
FileMustExist – lets the Open dialog accept only the name of an existing file
FileName – the file name shown when a dialog opens, and the path that the last Open or Save As dialog returned
Filter – the file-type list of the Open and Save As dialogs
HideReadOnly – hides the read-only choice of the Open dialog
InitialDir – the folder in which the Open and Save As dialogs start
MultiSelect – lets the Open dialog select more than one file
NewDialogStyle – selects the resizable Browse For Folder dialog with an edit box
NoChangeDir – keeps the current folder of the program as it was
OverwritePrompt – asks before the Save As dialog accepts the name of an existing file
PathMustExist – lets the Open and Save As dialogs accept only paths that exist
ReadOnly – sets the read-only flag of the Open dialog, which has no visible effect

Methods

AddFilter – appends a description and a pattern to the filter
ClearFilter – empties the filter
GetFileExtension – returns the part of a path from its last period
GetFileName – returns the part of a path after its last backslash
GetFileNameWithoutExt – returns the file name of a path without its extension
GetFilePath – returns the part of a path before its last backslash
OpenFile – runs a shell verb, by default open, on a file or a program
Reset – restores every property to its starting value
SelectAndOpenFile – shows the Open dialog and opens the chosen file or files
SetCodeFilters – replaces the filter with one for source code files
SetCommonFilters – replaces the filter with Text Files and All Files
SetDocumentFilters – replaces the filter with one for office documents
SetImageFilters – replaces the filter with one for image files
ShowBrowseForFolder – shows the Browse For Folder dialog and returns the chosen folder
ShowOpen – shows the Open dialog and returns the chosen file
ShowSave – shows the Save As dialog and returns the chosen file name