UTF-8与GB2312之间的互换

  UTF-8与GB2312之间的互换

作者：吴康彬
　　相信一定有不少的程序开发人员时常会遇到字符编码的问题，而这个问题也是非常让人头痛的。因为这些都是潜在的错误，要找出这些错误也得要有这方面的开发经验才行。特别是在处理xml文档时 ，该问题的出现就更加的频繁了，有一次用java写服务器端程序，用vc写客户端与之交互。交互的协议都是用xml写的。结果在通讯时老是发现数据接受不正确。纳闷！于是用抓取网络数据包工具抓取数据，后来才发现原来是java上xml的头是这样的<?xml version="1.0" encoding="UTF-8"?>,而vc上默认的是GB2312。所以一遇到汉字数据就不正确了。去网上找资料，这方面的文章好象特别少，针对像这样的问题，下面我介绍一下我自己写的一个转换程序。当然，程序很简单。如果有画蛇添足的地方，还望各位高手一笑了之。
　　如果您对UTF-8、Unicode、GB2312等还是很陌生的话，请查看http://www.linuxforum.net/books/UTF-8-Unicode.html，我这里就不浪费口舌了。下面介绍一下WinAPI的两个函数：WideCharToMultiByte、MultiByteToWideChar。

函数原型：

int WideCharToMultiByte(UINT CodePage, // code pageDWORD dwFlags, // performance and mapping flagsLPCWSTR lpWideCharStr, // wide-character stringint cchWideChar, // number of chars in stringLPSTR lpMultiByteStr, // buffer for new stringint cbMultiByte, // size of bufferLPCSTR lpDefaultChar, // default for unmappable charsLPBOOL lpUsedDefaultChar // set when default char used); //将宽字符转换成多个窄字符int MultiByteToWideChar(UINT CodePage, // code pageDWORD dwFlags, // character-type optionsLPCSTR lpMultiByteStr, // string to mapint cbMultiByte, // number of bytes in stringLPWSTR lpWideCharStr, // wide-character bufferint 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";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);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);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;}

　　程序都非常的简单，由于实在太穷。已经吃了两天的方便面。所以现在头昏，程序的详细说明就不写了。程序员到了像我这样的地步也真是少见。工资低没有办法。哎！！！！