Q198538: DocMgrEx.exe Assoc Multiple File Extensions w/1 Doc Type

Article: Q198538
Product(s): Microsoft C Compiler
Version(s): 5.0,6.0
Operating System(s): 
Keyword(s): kbfile kbSample kbDocView kbMFC kbVC500 kbVC600 kbDSupport kbGrpDSMFCATL
Last Modified: 13-MAY-2002

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The information in this article applies to:

- The Microsoft Foundation Classes (MFC), used with:
   - Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Professional Edition, versions 5.0, 6.0 
   - Microsoft Visual C++, 32-bit Learning Edition, version 6.0 
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SUMMARY
=======

DocMgrEx.exe is a sample that shows how to support multiple extensions
associated with one document type (or template) in MFC's Doc/View architecture.

This sample implements the code required to allow registration, unregistration,
file open, and file save operations in an otherwise regular MFC application. The
classes touched include the following:

- The CWinApp-derived class.

- The undocumented CDocManager class.

- A custom CFileDialog-derived class that allows transparent file operations
  with the newly defined CDocManagerEx.

MORE INFORMATION
================

The following files are available for download from the Microsoft Download
Center:

DocMgrEx.exe

NOTE: To Build this project with VS .NET, change the path in the #include of
AfxImpl.h on line 472 of DocManagerEx.cpp:

  Change from:
  #include <..\src\afximpl.h>

  To:
  #include <..\src\mfc\afximpl.h>

For additional information about how to download Microsoft Support files, click
the article number below to view the article in the Microsoft Knowledge Base:

  Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of
posting to scan this file for viruses. After it is posted, the file is housed on
secure servers that prevent any unauthorized changes to the file.


To change the extensions supported by different document types, or to add new
document types, edit the application's string table. In the string resource
associated with the document type resource ID, the fourth "\n" delimited
substring should read as follows:

  DocType files (.ex1;.ex2;ex3)

The 5th substring should read as follows:

  .ex1;.ex2;.ex3

NOTE: DocType is the external name of the document type; and ex1, ex2, ex3 are
the extensions you want to associate with your document type.

When testing the application, you will notice its behavior is similar to
DevStudio with regard to file open/save operations. For example, when trying to
open a file, the user specifies only a file name (without an extension), the
application will successively append the extensions from the currently active
filter, trying to build the file name of an existing file. If this yields no
result, the application will either tell the user that the file does not exist
(if the OFN_FILEMUSTEXIST flag was specified) or it will create a new file with
no extension. Saving operations are very similar.

Implementation Details
----------------------

To implement correct registration code we needed to override
CDocManager::RegisterShellFileTypes().

Unregistration is a bit more complicated, because the corresponding functions in
CWinApp and CDocManager were not declared virtual. Therefore, we needed to
implement the correct code in an override of
CDocManager::UnregisterShellFileTypes(), and copy and paste the code from
CWinApp::UnregisterShellFileTypes() and CWinApp::ProcessShellCommand() in our
own CWinApp-derived class.

To implement file operations transparently, we overrode
CDocManager::DoPromptFileName() and CDocManager::OpenDocumentFile(). To minimize
the number of changes, the global function MatchDocType() has been defined to
replace the use of CDocTemplate::MatchDocType() member function. The new
function behaves as expected when multiple extensions are provided for one
document template.

REFERENCES
==========

For additional information, please see the following article in the Microsoft
Knowledge Base:

  Q141921 HOWTO: How to Support Two File Extensions per MFC Document Type

Additional query words: DocMgrEx

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Keywords          : kbfile kbSample kbDocView kbMFC kbVC500 kbVC600 kbDSupport kbGrpDSMFCATL 
Technology        : kbAudDeveloper kbMFC
Version           : :5.0,6.0

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