Member Avatar for clutchkiller

MessageBox(NULL, (LPCTSTR)"Test1", (LPCTSTR)"Test1", MB_OK);

This code is popping up the window correctly, but it displays all squares. Whats wrong =(

Edited by clutchkiller because: n/a
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The squares mean the string you passed is being interpreted with the wrong character encoding. and were on the right trail: the compiler/project settings determine whether the Win32 macros call the ANSI or the wide (Unicode) API, and silencing the compiler with casts only hides the mismatch.

Quick compile-time check (prints a message during build):

#ifdef UNICODE
#pragma message("Building with UNICODE")
#else
#pragma message("Building without UNICODE")
#endif

If UNICODE/_UNICODE is defined, your calls must supply wide strings or call the ANSI API explicitly.

Two practical fixes:

  • Call the ANSI entry point when you have narrow (char*) text:
    MessageBoxA(NULL, "Sample text", "Caption", MB_OK);
  • Convert a multibyte/UTF-8 std::string to a wide string and call the Unicode entry:
    int n = MultiByteToWideChar(CP_UTF8, 0, s.c_str(), -1, nullptr, 0);
std::wstring ws(n, 0);
MultiByteToWideChar(CP_UTF8, 0, s.c_str(), -1, &ws[0], n);
MessageBoxW(NULL, ws.c_str(), ws.c_str(), MB_OK);

If squares remain after fixing the API/encoding, confirm the source text encoding (UTF-8 vs ANSI) and the font/glyph coverage used by the dialog. Avoid forcing types with casts — the compiler error/warning is trying to tell you there is an encoding mismatch.

Microsoft references:

This complements ’s pointer about project settings and ’s warning about blind casts.

Recommended Answers

All 7 Replies

Member Avatar for Ancient Dragon

Are you compiling your program for UNICODE ?

Member Avatar for clutchkiller

Im just using VC++ express 2008. All default settings so I couldnt tell ya

Member Avatar for Salem

> MessageBox(NULL, (LPCTSTR)"Test1", (LPCTSTR)"Test1", MB_OK);
Indiscriminate casting to get the compiler to STFU is a common problem.

Just because you muffled the compiler doesn't make your code good.

Take out the casts, then pay really close attention to the error messages.
http://msdn.microsoft.com/en-us/library/c426s321%28VS.71%29.aspx

Member Avatar for Ancient Dragon

Im just using VC++ express 2008. All default settings so I couldnt tell ya

Then that's probably the problem -- turn UNICODE off! To do that go to menu item Project --> Properties (the last item on that menu) --> Configuration Properties --> General. Then on the right side of the screen change Character Set (third from the bottom) to Not Set Also remove those unnecessary typecasts.

Member Avatar for clutchkiller

> MessageBox(NULL, (LPCTSTR)"Test1", (LPCTSTR)"Test1", MB_OK);
Indiscriminate casting to get the compiler to STFU is a common problem.

Just because you muffled the compiler doesn't make your code good.

Take out the casts, then pay really close attention to the error messages.
http://msdn.microsoft.com/en-us/libr...8VS.71%29.aspx

lawl.

Thanks dragon

Member Avatar for pspwxp fan

Then that's probably the problem -- turn UNICODE off! To do that go to menu item Project --> Properties (the last item on that menu) --> Configuration Properties --> General. Then on the right side of the screen change Character Set (third from the bottom) to Not Set Also remove those unnecessary typecasts.

There's something I don't understand: Why should UNICODE be off? It does contain more characters than ASCII doesn't it? What displays those characters if UNICODE doesn't?

Member Avatar for Salem

Well it would display a UNICODE string, were a UNICODE string actually passed as a parameter.

> (LPCTSTR)"Test1"
Would be stored in memory as 54 65 73 74 31 00
Now whilst 0x6554 is in the UNICODE space, it isn't going to be anything resembling Latin text.

Now saying L"Test1" would result in 54 00 65 00 73 00 74 00 31 00 00 00
These too are valid UNICODE characters, but 0x0054 is going to display a 'T' for you.

Better still (which seems to have been lost altogether by the OP) would be to say _TEXT("Test1") Then no matter how much you mess with the "turn it on or turn it off options" in the compiler, it will do "the right thing".

Further, if the OP has any ambitions of a career, then knowing about UNICODE is pretty much a given (well knowing more than how to turn it off at any rate).

commented: thnx :) +2
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