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UTF-8: 3位元組一個字元
UNICODE: 2位元組一個字元
GB2312: 1位元組一個字元
例子:
“你”字的UTF-8編碼: E4 BD A0 11100100 10111101 10100000
“你”的Unicode編碼: 4F 60 01001111 01100000
按照UTF-8的編碼規則,分解如下:xxxx0100 xx111101 xx100000
把除了x之外的數字拼接在一起,就變成“你”的Unicode編碼了。
注意UTF-8的最前面3個1,表示整個UTF-8串是由3個位元組構成的。
經過UTF-8編碼之後,再也不會出現敏感字元了,因為最高位始終為1。
類定義
class CChineseCode
{
public:
static void UTF_8ToUnicode(wchar_t* pOut,char *pText); // 把UTF-8轉換成Unicode
static void UnicodeToUTF_8(char* pOut,wchar_t* pText); //Unicode 轉換成UTF-8
static void UnicodeToGB2312(char* pOut,wchar_t uData); // 把Unicode 轉換成 GB2312
static void Gb2312ToUnicode(wchar_t* pOut,char *gbBuffer);// GB2312 轉換成 Unicode
static void GB2312ToUTF_8(string& pOut,char *pText, int pLen);//GB2312 轉為 UTF-8
static void UTF_8ToGB2312(string &pOut, char *pText, int pLen);//UTF-8 轉為 GB2312
};
類實作
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高低字的順序,低位元組在前,高位元組在後
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)
{
//如果是英文直接複制就可以
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] = '/0';
//傳回結果
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[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] = '/0';
pOut = newBuf;
delete []newBuf;
return;
}