• UTF-8:   3字节一个字符

• UNICODE: 2字节一个字符

• GB2312:  1字节一个字符

例子：
“你”字的UTF-8编码: E4 BD A0　　　　　　　　11100100 10111101 10100000
“你”的Unicode编码: 4F 60　　　　　　　　　   01001111 01100000

按照UTF-8的编码规则，分解如下：xxxx0100 xx111101 xx100000,把除了x之外的数字拼接在一起，就变成“你”的Unicode编码了。
注意UTF-8的最前面３个1，表示整个UTF-8串是由３个字节构成的。
经过UTF-8编码之后，再也不会出现敏感字符了，因为最高位始终为1。

类定义

class CChineseCode{
public:static void UTF_8ToUnicode(wchar_t* pOut,char *pText);  // 把UTF-8转换成Unicodestatic void UnicodeToUTF_8(char* pOut,wchar_t* pText);  //Unicode 转换成UTF-8static void UnicodeToGB2312(char* pOut,wchar_t uData);  // 把Unicode 转换成 GB2312 static void Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer);// GB2312 转换成　Unicodestatic void GB2312ToUTF_8(string& pOut,char *pText, int pLen);//GB2312 转为 UTF-8static void UTF_8ToGB2312(string &pOut, char *pText, int pLen);//UTF-8 转为 GB2312
};//类实现
void CChineseCode::UTF_8ToUnicode(wchar_t* pOut,char *pText){char* uchar = (char *)pOut;uchar[1] = ((pText[0] & 0x0F) << 4) + ((pText[1] >> 2) & 0x0F);uchar[0] = ((pText[1] & 0x03) << 6) + (pText[2] & 0x3F);return;
}void CChineseCode::UnicodeToUTF_8(char* pOut,wchar_t* pText){// 注意 WCHAR高低字的顺序,低字节在前，高字节在后char* pchar = (char *)pText;pOut[0] = (0xE0 | ((pchar[1] & 0xF0) >> 4));pOut[1] = (0x80 | ((pchar[1] & 0x0F) << 2)) + ((pchar[0] & 0xC0) >> 6);pOut[2] = (0x80 | (pchar[0] & 0x3F));return;
}void CChineseCode::UnicodeToGB2312(char* pOut,wchar_t uData){WideCharToMultiByte(CP_ACP,NULL,&uData,1,pOut,sizeof(wchar_t),NULL,NULL);return;
}     void CChineseCode::Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer){::MultiByteToWideChar(CP_ACP,MB_PRECOMPOSED,gbBuffer,2,pOut,1);return ;
}void CChineseCode::GB2312ToUTF_8(string& pOut,char *pText, int pLen){char buf[4];int nLength = pLen* 3;char* rst = new char[nLength];memset(buf,0,4);memset(rst,0,nLength);int i = 0;int j = 0;      while(i < pLen){//如果是英文直接复制就能if( *(pText + i) >= 0){rst[j++] = pText[i++]; }else{wchar_t pbuffer;Gb2312ToUnicode(&pbuffer,pText+i);UnicodeToUTF_8(buf,&pbuffer);unsigned short int tmp = 0;tmp = rst[j] = buf[0];tmp = rst[j+1] = buf[1];tmp = rst[j+2] = buf[2];    j += 3;i += 2;}}rst[j] = ’’;//返回结果pOut = rst;             delete []rst;     return;
}void CChineseCode::UTF_8ToGB2312(string &pOut, char *pText, int pLen){char * newBuf = new char[pLen];char Ctemp[4];memset(Ctemp,0,4);int i =0;int j = 0;while(i < pLen){//if(pText > 0){if( *(pText + i) >= 0){ newBuf[j++] = pText[i++];                       }else{WCHAR Wtemp;UTF_8ToUnicode(&Wtemp,pText + i);UnicodeToGB2312(Ctemp,Wtemp);newBuf[j] = Ctemp[0];newBuf[j + 1] = Ctemp[1];i += 3;    j += 2;   }}newBuf[j] = ’’;pOut = newBuf;delete []newBuf;return;
}