utf-8togb2312.c

C语言实现UTF-8与GB2312互换,提供详细的转换函数

C语言实现UTF-8与GB2312互换 
佚名 2008-6-11
 
int WideCharToMultiByte( 
 UINT CodePage, // code page 
 DWORD dwFlags, // performance and mapping flags 
 LPCWSTR lpWideCharStr, // wide-character string 
 int cchWideChar, // number of chars in string 
 LPSTR lpMultiByteStr, // buffer for new string 
 int cbMultiByte, // size of buffer 
 LPCSTR lpDefaultChar, // default for unmappable chars 
 LPBOOL lpUsedDefaultChar // set when default char used 
); //将宽字符转换成多个窄字符 

int MultiByteToWideChar( 
 UINT CodePage, // code page 
 DWORD dwFlags, // character-type options 
 LPCSTR lpMultiByteStr, // string to map 
 int cbMultiByte, // number of bytes in string 
 LPWSTR lpWideCharStr, // wide-character buffer 
 int cchWideChar // size of buffer 
);//将多个窄字符转换成宽字符       
需要用到的一些函数： 
CString CXmlProcess::HexToBin(CString string)//将16进制数转换成2进制 
{ 
 if( string == \"0\") return \"0000\"; 
 if( string == \"1\") return \"0001\"; 
 if( string == \"2\") return \"0010\"; 
 if( string == \"3\") return \"0011\"; 
 if( string == \"4\") return \"0100\"; 
 if( string == \"5\") return \"0101\"; 
 if( string == \"6\") return \"0110\"; 
 if( string == \"7\") return \"0111\"; 
 if( string == \"8\") return \"1000\"; 
 if( string == \"9\") return \"1001\"; 
 if( string == \"a\") return \"1010\"; 
 if( string == \"b\") return \"1011\"; 
 if( string == \"c\") return \"1100\"; 
 if( string == \"d\") return \"1101\"; 
 if( string == \"e\") return \"1110\"; 
 if( string == \"f\") return \"1111\"; 
 return \"\"; 
} 


CString CXmlProcess::BinToHex(CString BinString)//将2进制数转换成16进制 
{ 
 if( BinString == \"0000\") return \"0\"; [Page]
 if( BinString == \"0001\") return \"1\"; 
 if( BinString == \"0010\") return \"2\"; 
 if( BinString == \"0011\") return \"3\"; 
 if( BinString == \"0100\") return \"4\"; 
 if( BinString == \"0101\") return \"5\"; 
 if( BinString == \"0110\") return \"6\"; 
 if( BinString == \"0111\") return \"7\"; 
 if( BinString == \"1000\") return \"8\"; 
 if( BinString == \"1001\") return \"9\"; 
 if( BinString == \"1010\") return \"a\"; 
 if( BinString == \"1011\") return \"b\"; 
 if( BinString == \"1100\") return \"c\"; 
 if( BinString == \"1101\") return \"d\"; 
 if( BinString == \"1110\") return \"e\"; 
 if( BinString == \"1111\") return \"f\"; 
 return \"\"; 
} 

int CXmlProcess::BinToInt(CString string)//2进制字符数据转换成10进制整型 
{ 
 int len =0; 
 int tempInt = 0; 
 int strInt = 0; 
 for(int i =0 ;i < string.GetLength() ;i ++) 
 { 
         tempInt = 1; 
         strInt = (int)string.GetAt(i)-48; 
         for(int k =0 ;k < 7-i ; k++) 
         { 
   tempInt = 2*tempInt; 
         } 
         len += tempInt*strInt; 
 } 
 return len; 
}   

UTF-8转换成GB2312先把UTF-8转换成Unicode.然后再把Unicode通过函数WideCharToMultiByte转换成GB2312  
WCHAR* CXmlProcess::UTF_8ToUnicode(char *ustart)  //把UTF-8转换成Unicode 
{ 
 char char_one; 
 char char_two; 
 char char_three; 
 int Hchar; 
 int Lchar; 
 char uchar[2]; 
 WCHAR *unicode; 
 CString string_one; 
 CString string_two; 
 CString string_three; 
 CString combiString; 
 char_one = *ustart; 
 char_two = *(ustart+1); [Page]
 char_three = *(ustart+2); 
 string_one.Format(\"%x\",char_one); 
 string_two.Format(\"%x\",char_two); 
 string_three.Format(\"%x\",char_three); 
 string_three = string_three.Right(2); 
 string_two = string_two.Right(2); 
 string_one = string_one.Right(2); 
 string_three = HexToBin(string_three.Left(1))+HexToBin(string_three.Right(1)); 
 string_two = HexToBin(string_two.Left(1))+HexToBin(string_two.Right(1)); 
 string_one = HexToBin(string_one.Left(1))+HexToBin(string_one.Right(1)); 
 combiString = string_one +string_two +string_three; 
 combiString = combiString.Right(20); 
 combiString.Delete(4,2); 
 combiString.Delete(10,2); 
 Hchar = BinToInt(combiString.Left(8)); 
 Lchar = BinToInt(combiString.Right(8)); 
 uchar[1] = (char)Hchar; 
 uchar[0] = (char)Lchar; 
 unicode = (WCHAR *)uchar; 
 return unicode; 
} 

char * CXmlProcess::UnicodeToGB2312(unsigned short uData)  //把Unicode 转换成 GB2312 
{ 
 char *buffer ; 
 buffer = new char[sizeof(WCHAR)]; 
 WideCharToMultiByte(CP_ACP,NULL,&uData,1,buffer,sizeof(WCHAR),NULL,NULL); 
 return buffer; 
}       
　　GB2312转换成UTF-8：先把GB2312通过函数MultiByteToWideChar转换成Unicode.然后再把Unicode通过拆开Unicode后拼装成UTF-8。 
WCHAR * CXmlProcess::Gb2312ToUnicode(char *gbBuffer)  //GB2312 转换成　Unicode 
{  
 WCHAR *uniChar; 
 uniChar = new WCHAR[1]; 
 ::MultiByteToWideChar(CP_ACP,MB_PRECOMPOSED,gbBuffer,2,uniChar,1); 
 return uniChar; 
} 
char * CXmlProcess::UnicodeToUTF_8(WCHAR *UniChar) // Unicode 转换成UTF-8 
{ 
 char *buffer; 
 CString strOne; 
 CString strTwo; 
 CString strThree; 
 CString strFour; 
 CString strAnd; 
 buffer = new char[3]; 
 int hInt,lInt; 
 hInt = (int)((*UniChar)/256); 
 lInt = (*UniChar)%256; 
 CString string ; 
 string.Format(\"%x\",hInt); 
 strTwo = HexToBin(string.Right(1)); 
 string = string.Left(string.GetLength() - 1); 
 strOne = HexToBin(string.Right(1)); 
 string.Format(\"%x\",lInt); [Page]
 strFour = HexToBin(string.Right(1)); 
 string = string.Left(string.GetLength() -1); 
 strThree = HexToBin(string.Right(1)); 
 strAnd = strOne +strTwo + strThree + strFour; 
 strAnd.Insert(0,\"1110\"); 
 strAnd.Insert(8,\"10\"); 
 strAnd.Insert(16,\"10\"); 
 strOne = strAnd.Left(8); 
 strAnd = strAnd.Right(16); 
 strTwo = strAnd.Left(8); 
 strThree = strAnd.Right(8); 
 *buffer = (char)BinToInt(strOne); 
 buffer[1] = (char)BinToInt(strTwo); 
 buffer[2] = (char)BinToInt(strThree); 
 return buffer; 
}      
例子：将GB2312转换成UTF-8的调用：  
char * CXmlProcess::translateCharToUTF_8(char *xmlStream, int len)  
{ 
 int newCharLen =0 ; 
 int oldCharLen = 0; 
 int revCharLen = len; 
 char* newCharBuffer; 
 char* finalCharBuffer; 
 char *buffer ; 
 CString string; 
 buffer  = new char[sizeof(WCHAR)]; 
 newCharBuffer = new char[int(1.5*revCharLen)];//设置最大的一个缓冲区 
 while(oldCharLen < revCharLen) 
 { 
  if( *(xmlStream + oldCharLen) >= 0) 
  { 
   *(newCharBuffer+newCharLen) = *(xmlStream +oldCharLen); 
   newCharLen ++; 
   oldCharLen ++; 
}//如果是英文直接复制就可以 
  else 
  { 
   WCHAR *pbuffer = this->Gb2312ToUnicode(xmlStream+oldCharLen); 
   buffer = this->UnicodeToUTF_8(pbuffer); 
   *(newCharBuffer+newCharLen) = *buffer; 
   *(newCharBuffer +newCharLen +1) = *(buffer + 1); 
   *(newCharBuffer +newCharLen +2) = *(buffer + 2); 
   newCharLen += 3; 
   oldCharLen += 2; 
  } 
 } 
 newCharBuffer[newCharLen] = ’’\\0’’; 
 CString string1 ; 
 string1.Format(\"%s\",newCharBuffer); 
 finalCharBuffer = new char[newCharLen+1]; 
 memcpy(finalCharBuffer,newCharBuffer,newCharLen+1); 
 return finalCharBuffer; 
}