Question

Can anyone help me to correct this code:

    char szBuff[64];
    sprintf(szBuff, "%p", m_hWnd);
    MessageBox(NULL, szBuff, L"Test print handler", MB_OK);

The error is, it cant convert the 2nd parameter to LPCWSTR.

Answer 1

For this specific case, the fix is quite simple:

wchar_t szBuff[64];
swprintf(szBuff, L"%p", m_hWnd);
MessageBox(NULL, szBuff, L"Test print handler", MB_OK);

That is, use Unicode strings throughout. In general, when programming on Windows, using wchar_t and UTF-16 is probably the simplest. It depends on how much interaction with other systems you have to do, of course.

For the general case, if you’ve got an ASCII (or char *) string, use either WideCharToMultiByte for the general case, or mbstowcs as @Matthew points out for simpler cases (mbstowcs works if the string is in the current C locale).