FILE: OfnKing Demonstrates CFileDialog Customization

ID: Q195034

The information in this article applies to:

SUMMARY

OfnKing demonstrates how to use and customize the Explorer-style CFileDialog. This is the new type of Open File common dialog box supported on Windows 95 and Windows NT 4.0.

OfnKing provides a custom template with controls added to the standard set. It also shows how to hide and move the standard controls. In addition, OfnKing demonstrates DDX/DDV and context-sensitive help support with controls on the custom template.

Programmers often like to use the common file dialog box to obtain a folder name or to include folder names with the list of retrieved selected files. OfnKing demonstrates a quick use of the new SHBrowseForFolder function, which is the recommended method for the former. As for the latter, as an advanced technique of customization, OfnKing shows how to access the listview control on the common dialog box and obtain a list of Display names of files as well as folders.


MORE INFORMATION

The following file is available for download from the Microsoft Software Library:

~ OfnKing.EXE
Release Date: Oct-30-1998

For more information about downloading files from the Microsoft Software Library, please see the following article in the Microsoft Knowledge Base:
Q119591 How to Obtain Microsoft Support Files from Online Services
The primary functionality of this sample rests in the CCustomFileDialog class, defined in CustomFileDialog.cpp and CustomFileDialog.h. The custom file dialog box is executed by either clicking CfileDialog, then clicking Go, or by clicking Open on the File menu. Three options are available for choosing what customized file dialog box will be shown: whether it has the Explorer style, whether it has a Custom Template, and whether it allows the user to select multiple files.

The Custom Template version provides a few controls that allow the user to store a list of file names and directories from several different directories. This list comes directly from the listview control on the dialog box, and therefore it is composed only of Display Names. Directory names should be accurate, but file names could potentially be stripped of their extensions (this is based on whether the user has chosen this option in the standard Explorer.)

Below is a listing of the techniques that OfnKing demonstrates:

Obtaining a List of Selected Files When Using Multi-Select

At the end of CMainFrame::OnDoDialog is a for loop that uses the GetStartPosition() and GetNextPathName() functions to iterate through the multiple file selections and add the names to one of the list controls. Unfortunately, in versions of MFC prior to 4.2, the GetNextPathName() function made some incorrect assumptions. OfnKing provides a fixed version.

Adding to the Recent File List

The loop mentioned above also adds the filenames to the recent file list. This is as easy as calling the CWinApp::AddToRecentFileList() function.

Selecting a directory

The CMainFrame::OnDirectorySelect() function demonstrates selecting a directory. It uses SHBrowseForFolder() to read in an initial directory for CFileDialog. This directory is added to one of the panes in the status bar.

Providing a custom template for CFileDialog

With the old-style common file dialog box (that is, non-Explorer), the template used was the WHOLE file dialog box, with all of the standard controls. Now, with Explorer dialog boxes, you provide only the controls you would like to add to the dialog box. Your template is repositioned and resized to fit the standard controls when the CFileDialog window is first created. Or, if you want precise positioning of the standard controls, you can place a static control with an ID of stc32 on your template to indicate where you want the standard controls to be placed. This is the technique OfnKing uses.

Using DDX/DDV with Your Own Controls on CFileDialog

Unfortunately, the Class Wizard code is not complete when matching a custom template to a CFileDialog object. By adding the missing Class Wizard comments, Class Wizard lets you map control and value variables to your own controls and read values into them.

See CCustomFileDialog::DoDataExchange().

Context-Sensitive Help Support

CCustomFileDialog::OnHelp() is called when the user clicks the standard Help button on the common file dialog box.

CCustomFileDialog::OnContextMenu() is called when the user right-clicks one of the custom controls, such as the select items button. This brings up a menu with the "What's This?" item.

CCustomFileDialog::OnHelpInfo() is called when the WM_HELP message is generated by clicking the ? on the caption bar.

All three of these options make quick use of the WinHelp command.

MakeHelp.bat was modified to map IDC_ to help context IDs, and the standard MFC help support .rtf file was pared down to just a few entries.

Reading Directory Names from listview

The common file dialog box does not support selection of folders. That is, It is not possible to retrieve the name of a selected folder nor will the common file dialog box return folder names in the OPENFILENAME structure on closing. However, in some cases, it might be handy to get selected folder names as well. One example: a file archival and compression utility might want to allow a user to package up all of the files in one directory by just selecting that directory.

As a demonstration of customization techniques, OfnKing shows how to access the listview control on CfileDialog, and read through the list of Display names to obtain a "complete" list of all selected files and directories. The main functionality for this is in ReadListViewNames().

Because the list obtained consists of display names, the file names obtained may not be complete. Currently, extensions are stripped for certain known file types based on system preferences. However, folder names will probably not be altered. The application of this information is left to the observer.

NOTE: This technique may break with future versions of the common dialog boxes. However, because it just stops working, rather than crashing the program, if the dialog box implementation changes, this method is relatively safe.

Additional Notes on the OfnKing Sample

The OfnKing sample was originally created using AppWizard, which generated a skeleton application with a set of basic files. Most of the code in this sample that represents a change to the original AppWizard code is marked with the comments "// CHANGE":

The rest of the OfnKing sample contains a summary of what you will find in each of the files that make up your OfnKing application:

CustomFileDialog.cpp
CustomFileDialog.h
The implementation and header file for the CCustomFileDialog class, discussed above.
OfnKing.h
This is the main header file for the application. It includes other Project-specific headers (including Resource.h) and declares the COfnKingApp application class.
OfnKing.cpp
This is the main application source file that contains the application class COfnKingApp.
OfnKing.rc
This is a listing of all of the Microsoft Windows resources that the program uses; it includes the icons, bitmaps, and cursors that are stored in the RES subdirectory. This file can be directly edited in Microsoft Developer Studio.
res\OfnKing.ico
This is an icon file, which is used as the application's icon. This icon is included by the main resource file OfnKing.rc.
res\OfnKing.rc2
This file contains resources that are not edited by Microsoft Developer Studio. You should place all resources not editable by the resource editor in this file.
OfnKing.clw
This file contains information used by ClassWizard to edit existing classes or add new classes. ClassWizard also uses this file to store information needed to create and edit message maps and dialog data maps and to create prototype member functions.

For the Main Frame Window

MainFrm.h, MainFrm.cpp
These files contain the frame class CMainFrame, which is derived from CMDIFrameWnd and controls all MDI frame features.
res\Toolbar.bmp
This bitmap file is used to create tiled images for the toolbar. The initial toolbar and status bar are constructed in the CMainFrame class. Edit this toolbar bitmap along with the array in MainFrm.cpp to add more toolbar buttons.

AppWizard Creates One Document Type and One View

OfnKingDoc.h, OfnKingDoc.cpp - the document
These files contain your COfnKingDoc class. Edit these files to add your special document data and to implement file saving and loading (via COfnKingDoc::Serialize).
OfnKingView.h, OfnKingView.cpp - the view of the document
These files contain your COfnKingView class. COfnKingView objects are used to view COfnKingDoc objects.
res\OfnKingDoc.ico
This is an icon file, which is used as the icon for MDI child windows for the COfnKingDoc class. This icon is included by the main resource file OfnKing.rc.

Help Support

MakeHelp.bat
Use this batch file to create your application's Help file, OfnKing.hLP.
OfnKing.hpj
This file is the Help Project file used by the Help compiler to create your application's Help file.
hlp\OfnKing.rtf
This file contains the context-sensitive help topics for the dialog box.

Other Standard Files

StdAfx.h, StdAfx.cpp
These files are used to build a precompiled header (PCH) file named OfnKing.pch and a precompiled types file named StdAfx.obj.
Resource.h
This is the standard header file, which defines new resource IDs. Microsoft Developer Studio reads and updates this file.

Other Notes

If your application uses MFC in a shared DLL, and your application is in a language other than the operating system's current language, you need to copy the corresponding localized resources Mfc40xxx.dll from the Microsoft Visual C++ CD-ROM onto the system or system32 directory, and rename it to be Mfcloc.dll ("XXX" stands for the language abbreviation; for example, Mfc40deu.dll contains resources translated to German). If you don't do this, some of the UI elements of your application remain in the language of the operating system. 


Keywords          : kbfile kbMFC kbVC400 kbVC410 kbVC420 kbVC500 kbVC600 
Version           : WINNT:4.0,4.1,4.2,5.0,6.0
Platform          : winnt 
Issue type        :

Last Reviewed: July 16, 1999