.std::string轉utf8字符串

1. utf8轉std::string
   轉換過程：先將utf8轉雙字節Unicode編碼，再通過WideCharToMultiByte將寬字符轉換爲多字節。
   //———————————————————————–
   std::string UTF8_To_string(const std::string & str)
   {
   int nwLen = MultiByteToWideChar(CP_UTF8, 0, str.c_str(), -1, NULL, 0);

wchar_t * pwBuf = new wchar_t[nwLen + 1];//一定要加1，不然會出現尾巴
memset(pwBuf, 0, nwLen * 2 + 2);

MultiByteToWideChar(CP_UTF8, 0, str.c_str(), str.length(), pwBuf, nwLen);

int nLen = WideCharToMultiByte(CP_ACP, 0, pwBuf, -1, NULL, NULL, NULL, NULL);

char * pBuf = new char[nLen + 1];
memset(pBuf, 0, nLen + 1);

WideCharToMultiByte(CP_ACP, 0, pwBuf, nwLen, pBuf, nLen, NULL, NULL);

std::string retStr = pBuf;

delete []pBuf;
delete []pwBuf;

pBuf = NULL;
pwBuf = NULL;

return retStr;
}
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// [8/19/2009 Leezhm]
// translate ascii characters to utf-8 characters

2.std::string轉utf8字符串
轉換過程：與1過程相反
//————————————————————————
std::string string_To_UTF8(const std::string & str)
{
int nwLen = ::MultiByteToWideChar(CP_ACP, 0, str.c_str(), -1, NULL, 0);

wchar_t * pwBuf = new wchar_t[nwLen + 1];//一定要加1，不然會出現尾巴
ZeroMemory(pwBuf, nwLen * 2 + 2);

::MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.length(), pwBuf, nwLen);

int nLen = ::WideCharToMultiByte(CP_UTF8, 0, pwBuf, -1, NULL, NULL, NULL, NULL);

char * pBuf = new char[nLen + 1];
ZeroMemory(pBuf, nLen + 1);

::WideCharToMultiByte(CP_UTF8, 0, pwBuf, nwLen, pBuf, nLen, NULL, NULL);

std::string retStr(pBuf);

delete []pwBuf;
delete []pBuf;

pwBuf = NULL;
pBuf = NULL;

return retStr;
}
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