WindowsAPIエラー

http://support.microsoft.com/kb/94999/ja

/**
* Windows API エラー
*/
CString OutputError( LPCTSTR str )
{
int err = ::GetLastError();

LPVOID lpMessageBuffer;

::FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
NULL,
err,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR)(&lpMessageBuffer),
0,
NULL );

CString err_str = strprintf( _T("%s: %d:%s\n"), str, err, lpMessageBuffer );

::LocalFree( lpMessageBuffer );

return err_str;
}