Piecewise conversion of an MFC app to Unicode/MBCS

Question

I have a large MFC application that I am extending to allow for multi-lingual input. At the moment I need to allow the user to enter Unicode data in edit boxes on a single dialog.

Is there a way to do this without turning UNICODE or MBCS on for the entire application? I only need a small part of the application converted at the moment. Is it possible to do this piecewise, and if so, how?

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Clarification: I could use ::GetWindowTextW() to get Unicode information out of the window. I am trying to figure out how to allow the user to enter Unicode text in the window. Currently, characters the user types outside of the windows-1252 codepage show up as '?'. Is there a way to fix this?

Answer 1

To allow CEdit to show Unicode characters you should create it with CreateWindowW function. I've just tested it in ANSI MFC program.

// allows Unicode characters
CreateWindowW( L"EDIT", L"", WS_CHILD|WS_VISIBLE, 10, 10, 50, 20, GetSafeHwnd(), 0, 0, 0 );

// shows Unicode characters as ?
CreateWindow( "EDIT", "", WS_CHILD|WS_VISIBLE, 10, 10, 50, 20, GetSafeHwnd(), 0, 0, 0 );

You could create all edit boxes manually in OnInitDialog function of dialog box. And later subclass them to custom CMyEdit class with Unicode support.

Answer 2

Can you replace these edit boxes with rich edit controls? Then you could enter international characters even in a non-Unicode build; internally, they would be rtf-encoded, but then when you stream the text out from the control, you can use the SF_UNICODE format to get the Unicode representation.

Answer 3

This PowerPoint slideshow may be of interest to you -- it's a bit old (2000) but it talks about converting a program to mixed ANSI/Unicode.

Case Study: Porting an MFC Application to Unicode