KnowledgeBase Archive

An Archive of Early Microsoft KnowledgeBase Articles

View on GitHub

Q66926: INFO: Dialog Box Creation Fails If Text Starts w/ Character 255

Article: Q66926
Product(s): Microsoft Windows Software Development Kit
Version(s): WINDOWS:3.1
Operating System(s): 
Keyword(s): kb16bitonly kbDlg kbSDKPlatform
Last Modified: 10-JUN-1999

3.00 3.10
WINDOWS
kbprg

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Windows Software Development Kit (SDK) 3.1 
-------------------------------------------------------------------------------

SUMMARY
=======

Text strings in a dialog box resource cannot start with the character
represented by the value 255 (0xFF). In the ANSI character set, this character
is the letter "y" with a diaeresis mark, which is used primarily in Nordic
languages. If Windows encounters this situation, a call to DialogBox() or
CreateDialog() will fail.

The following are two possible solutions:

- Create the control with some "dummy" text. Then, use the SetDlgItemText()
  function during the processing of the WM_INITDIALOG message to manually set
  the text of the control to its proper value. This is the preferred method.

  -or-

- Instead of starting the text with the 255 character, use a space, followed by
  a backspace character and the 255 character. For example, the text in the
  dialog box script can be " \0008x", where "x" is the 255 character. The
  embedded backspace erases the space, leaving only the 255 character.

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

Windows uses the number 255 to indicate that a resource is represented by
ordinal value instead of by a string name. For example, when a dialog box is
declared as follows:

  AboutBox    DIALOG  ...

the text "AboutBox" appears in the .RES file. However, using the following

  1           DIALOG  ...

places the bytes 0xFF 0x01 0x00 into the .RES file. The 0xFF is used to indicate
that the next two bytes are the ordinal value for this resource.

When creating a dialog box, the Windows Dialog Manager scans through each string
in the dialog box template to find the null terminator. However, when a string
that starts with 255 is encountered, it is interpreted as an ordinal value. In
this situation, Windows incorrectly skips the next 2 bytes and treats the new
position as the next piece of data in the dialog box template.

Whenever this occurs, the remainder of the dialog box template is interpreted
incorrectly, and Windows tries to create controls of unknown classes, with
unknown styles, in unknown locations. This causes the dialog box creation to
fail.


Additional query words: 3.00 3.10 dialog box ANSI

======================================================================
Keywords          : kb16bitonly kbDlg kbSDKPlatform 
Technology        : kbAudDeveloper kbWin3xSearch kbSDKSearch kbWinSDKSearch kbWinSDK310
Version           : WINDOWS:3.1
Issue type        : kbinfo

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.