在mfc中輸出txt亂碼，這個問題困擾我半天，希望對大家有所幫助：我是把string轉utf8

1.  utf8轉std::string

轉換過程：先將utf8轉雙位元組Unicode編碼，再通過WideCharToMultiByte將寬字元轉換為多位元組。
//----------------------------------------------------------------------- 
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];//

2.std::string轉utf8字串

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; 
} 
//////////////////////////////////////////////////////////////////////////