VC Character Set Unicode or Multi-Byte

http://msdn.microsoft.com/en-us/library/ey142t48(v=vs.71).aspx

What is Unicode?

What is Multi-Byte?

 

How to Convert between Unicode and Multi-Byte?

Microsoft Support：

http://msdn.microsoft.com/en-us/library/dd374130(v=vs.85).aspx

http://support.microsoft.com/kb/138813

ANSI to Unicode

wstring ANSIToUnicode( const string& str )
 {
 int len = 0;
 len = str.length();
 int unicodeLen = ::MultiByteToWideChar( CP_ACP,
             0,
             str.c_str(),
             -1,
             NULL,
             0 ); 
 wchar_t * pUnicode; 
 pUnicode = new wchar_t[unicodeLen+1]; 
 memset(pUnicode,0,(unicodeLen+1)*sizeof(wchar_t)); 
 ::MultiByteToWideChar( CP_ACP,
          0,
          str.c_str(),
          -1,
          (LPWSTR)pUnicode,
          unicodeLen ); 
 wstring rt; 
 rt = ( wchar_t* )pUnicode;
 delete pUnicode; 
 return rt; 
 }

Unicode to ANSI

string UnicodeToANSI( const wstring& str )
 {
 char*     pElementText;
 int    iTextLen;
 // wide char to multi char
 iTextLen = WideCharToMultiByte( CP_ACP,
          0,
          str.c_str(),
          -1,
          NULL,
         0,
          NULL,
          NULL );
 pElementText = new char[iTextLen + 1];
 memset( ( void* )pElementText, 0, sizeof( char ) * ( iTextLen + 1 ) );
 ::WideCharToMultiByte( CP_ACP,
          0,
          str.c_str(),
          -1,
          pElementText,
          iTextLen,
          NULL,
          NULL );
 string strText;
 strText = pElementText;
 delete[] pElementText;
 return strText;
 }

How a Regular DLL with Unicode Call a Extension DLL with Multi-Byte?