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Q123465: PRB: Cannot View Unicode Strings in the Watch Window

Article: Q123465
Product(s): Microsoft C Compiler
Version(s): 2.0
Operating System(s): 
Keyword(s): kbdisplay kbDebug kbide
Last Modified: 15-FEB-2002

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The information in this article applies to:

- The Integrated Debugger, used with:
   - Microsoft Visual C++, 32-bit Editions, version 2.0 
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SYMPTOMS
========

When trying to watch a Unicode string in the Watch window, you see only the
first byte, or it is displayed incorrectly.

CAUSE
=====

Making the debugger "Unicode aware" at the display level involves the
complicated task of setting and using locales and fonts properly. This is
especially difficult if they are not the ones currently in use. This
functionality has not yet been implemented.

RESOLUTION
==========

You can use the 'm' format symbol to see the first eight characters of a string,
or you could use the 'ma' format symbol to see the first 32 characters. For
example, if you have a declaration in your code like this:

     wchar_t *pStr = L"Some string";

Adding the expression "pStr,m" (without the quotation marks) to the Watch window
results in a memory dump of the first 16 bytes, immediately followed by the
ASCII equivalent, similar to this:

  S.o.m.e. .s.t.r.

The periods are place holders for null bytes, which show up behind their
corresponding characters because wchar_t's are defined as two-byte unsigned
shorts, whose bytes are thus reversed in memory. (This is why only the first
character 'S' would be displayed by default in the example above. The debugger
sees the null byte following the 'S' and assumes it is the string terminator.)

This method will obviously work only with short strings. As an alternative, you
can open up the memory window and point it to the starting address of your
string. Note that dragging or dropping the string's address from the Watch
window to the Memory window makes this much easier.

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

For future versions, Microsoft is considering ways to allow watching Unicode
strings directly using the current locale.

Additional query words:

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Keywords          : kbdisplay kbDebug kbide 
Technology        : kbVCsearch kbAudDeveloper kbIntegratedDebugger
Version           : :2.0
Issue type        : kbprb

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