Windows 下字节转换

Windows 下字节转换

 #include <string>
 #include <windows.h>

 class CharsConversion
 {
 public:
     static bool MultiByte2UTF8( const std::string&, std::string& );  

     static bool UTF82MultiByte( const std::string&, std::string& );

     static bool MultiByte2Unicode( const std::string&, std::wstring&  );

     static bool Unicode2MultiByte( const std::wstring&,  std::string& );

     static bool UTF82Unicode( const std::string&, std::wstring& );

     static bool Unicode2UTF8( const std::wstring&, std::string& );
 };

 bool CharsConversion::MultiByte2UTF8( const std::string &strMB, std::string& strUTF8 )
 {
     //Note: If this cbMultiByte is –1, the string is assumed to be null terminated and the length is calculated automatically.
     //Note: If cbMultiByte is strMB.size(), this function will not include the null terminated, it's an error.
     //Note: Or, if cbMultiByte is strMB.size() + 1, this function will be right.
     int nWCLen = MultiByteToWideChar( CP_ACP, , strMB.c_str(), -, NULL,  );  

     wchar_t* pszWC = new (std::nothrow) wchar_t[nWCLen];
     if ( nullptr == pszWC ) return false;

     //Note: The return value includes the NULL termination character.
     int nRtn = MultiByteToWideChar( CP_ACP, , strMB.c_str(), -, pszWC, nWCLen );
     if( nRtn != nWCLen ) { delete[] pszWC; return false; }  

     // WindChar 2 UTF8
     //Note: nWClen and -1 both ok.
     int nUTF8Len = WideCharToMultiByte( CP_UTF8, , pszWC, nWCLen, NULL, , NULL, NULL );
     if ( nUTF8Len <=  ) { delete [] pszWC; return false; }  

     strUTF8.resize( nUTF8Len );
     nRtn = WideCharToMultiByte( CP_UTF8, , pszWC, nWCLen, &strUTF8[], nUTF8Len, NULL, NULL );
     delete [] pszWC;  

     if ( nRtn != nUTF8Len ) { strUTF8.clear(); return false; }  

     return true;
 } 

 bool CharsConversion::UTF82MultiByte( const std::string &strUTF8, std::string &strMB )
 {
     //Note: cchWideChar must be -1 or strUTF8.size()+1.
     int nWCLen = MultiByteToWideChar( CP_UTF8, , strUTF8.c_str(), -, NULL,  );  

     WCHAR* pszWC = new (std::nothrow) WCHAR[nWCLen];
     if ( nullptr == pszWC ) return false;

     int nRtn = MultiByteToWideChar( CP_UTF8, , strUTF8.c_str(), -, pszWC, nWCLen );
     if ( nRtn != nWCLen ) { delete[] pszWC; return false; }  

     //WideChar 2 MB
     int nMBLen = WideCharToMultiByte( CP_ACP, , pszWC, nWCLen/*or -1*/, NULL, , NULL, NULL );
     if ( nMBLen <=  ) { delete [] pszWC; return false; } 

     strMB.resize( nMBLen );
     nRtn = WideCharToMultiByte( CP_ACP, , pszWC, nWCLen/*or -1*/, &strMB[], nMBLen, NULL, NULL );
     delete [] pszWC;  

     if ( nRtn != nMBLen ) { strMB.clear(); return false; } 

     return true;
 }  

 bool CharsConversion::MultiByte2Unicode( const std::string &strMB, std::wstring &strUC )
 {
     //Note: cbMultiByte can be strMB.size() + 1 or -1.
     int nUCLen = MultiByteToWideChar( CP_ACP, , strMB.c_str(), -, NULL,  );  

     if ( nUCLen <=  )  return false;  

     strUC.resize( nUCLen );  

     int nRtn = MultiByteToWideChar( CP_ACP, , strMB.c_str(), -, &strUC[], nUCLen );  

     if ( nRtn != nUCLen ) { strUC.clear(); return false; }  

     return true;
 }  

 bool CharsConversion::Unicode2MultiByte( const std::wstring &strUC,  std::string &strMB )
 {
     //Note: cchWideChar  must be -1 or strUC.size()+1.
     int nMBLen = WideCharToMultiByte( CP_ACP, , strUC.c_str(), -, NULL, , NULL, NULL );  

     if ( nMBLen <=  ) return false;  

     strMB.resize( nMBLen ); 

     int nRtn = WideCharToMultiByte( CP_ACP, , strUC.c_str(), -, &strMB[], nMBLen, NULL, NULL );  

     if( nRtn != nMBLen ) { strMB.clear(); return false; }  

     return true;
 }  

 bool CharsConversion::UTF82Unicode( const std::string &strUTF8, std::wstring &strUC )
 {
     //Note: cbMultiByte can be strUTF8.size() + 1 or -1.
     int nUCLen = MultiByteToWideChar( CP_UTF8, , strUTF8.c_str(), -, NULL,  );  

     if ( nUCLen <=  ) return false;

     strUC.resize( nUCLen );  

     int nRtn = MultiByteToWideChar( CP_UTF8, , strUTF8.c_str(), -, &strUC[], nUCLen );  

     if ( nRtn != nUCLen ) { strUC.clear(); return false; }  

     return true;
 }  

 bool CharsConversion::Unicode2UTF8( const std::wstring &strUC, std::string &strUTF8 )
 {
     //Note: cchWideChar  must be -1 or strUC.size()+1.
     int nUTF8Len = WideCharToMultiByte( CP_UTF8, , strUC.c_str(), -, NULL, , NULL, NULL );

     if ( nUTF8Len <=  ) return false;  

     strUTF8.resize( nUTF8Len ); 

     int nRtn = WideCharToMultiByte( CP_UTF8, , strUC.c_str(), -, &strUTF8[], nUTF8Len, NULL, NULL );  

     if ( nRtn != nUTF8Len ) { strUTF8.clear(); return false; }  

     return true;
 }