Question

std：string什么函数可以将ansii字符串转化成utf8

Answer 1

[code=c++]
// 多字节编码转为UTF8编码
bool MBToUTF8(vector<char>& pu8, const char* pmb, int32 mLen)
{
// convert an MBCS string to widechar
int32 nLen = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, NULL, 0);

WCHAR* lpszW = NULL;
try
{
lpszW = new WCHAR[nLen];
}
catch(bad_alloc &memExp)
{
return false;
}

int32 nRtn = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, lpszW, nLen);

if(nRtn != nLen)
{
delete[] lpszW;
return false;
}
// convert an widechar string to utf8
int32 utf8Len = WideCharToMultiByte(CP_UTF8, 0, lpszW, nLen, NULL, 0, NULL, NULL);
if (utf8Len <= 0)
{
return false;
}
pu8.resize(utf8Len);
nRtn = WideCharToMultiByte(CP_UTF8, 0, lpszW, nLen, &*pu8.begin(), utf8Len, NULL, NULL);
delete[] lpszW;

if (nRtn != utf8Len)
{
pu8.clear();
return false;
}
return true;
}

// UTF8编码转为多字节编码
bool UTF8ToMB(vector<char>& pmb, const char* pu8, int32 utf8Len)
{
// convert an UTF8 string to widechar
int32 nLen = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, NULL, 0);

WCHAR* lpszW = NULL;
try
{
lpszW = new WCHAR[nLen];
}
catch(bad_alloc &memExp)
{
return false;
}

int32 nRtn = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, lpszW, nLen);

if(nRtn != nLen)
{
delete[] lpszW;
return false;
}

// convert an widechar string to Multibyte
int32 MBLen = WideCharToMultiByte(CP_ACP, 0, lpszW, nLen, NULL, 0, NULL, NULL);
if (MBLen <=0)
{
return false;
}
pmb.resize(MBLen);
nRtn = WideCharToMultiByte(CP_ACP, 0, lpszW, nLen, &*pmb.begin(), MBLen, NULL, NULL);
delete[] lpszW;

if(nRtn != MBLen)
{
pmb.clear();
return false;
}
return true;
}

// 多字节编码转为Unicode编码
bool MBToUnicode(vector<wchar_t>& pun, const char* pmb, int32 mLen)
{
// convert an MBCS string to widechar
int32 uLen = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, NULL, 0);

if (uLen<=0)
{
return false;
}
pun.resize(uLen);

int32 nRtn = MultiByteToWideChar(CP_ACP, 0, pmb, mLen, &*pun.begin(), uLen);

if (nRtn != uLen)
{
pun.clear();
return false;
}
return true;
}

//Unicode编码转为多字节编码
bool UnicodeToMB(vector<char>& pmb, const wchar_t* pun, int32 uLen)
{
// convert an widechar string to Multibyte
int32 MBLen = WideCharToMultiByte(CP_ACP, 0, pun, uLen, NULL, 0, NULL, NULL);
if (MBLen <=0)
{
return false;
}
pmb.resize(MBLen);
int nRtn = WideCharToMultiByte(CP_ACP, 0, pun, uLen, &*pmb.begin(), MBLen, NULL, NULL);

if(nRtn != MBLen)
{
pmb.clear();
return false;
}
return true;
}

// UTF8编码转为Unicode
bool UTF8ToUnicode(vector<wchar_t>& pun, const char* pu8, int32 utf8Len)
{
// convert an UTF8 string to widechar
int32 nLen = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, NULL, 0);
if (nLen <=0)
{
return false;
}
pun.resize(nLen);
int32 nRtn = MultiByteToWideChar(CP_UTF8, 0, pu8, utf8Len, &*pun.begin(), nLen);

if(nRtn != nLen)
{
pun.clear();
return false;
}

return true;
}

// Unicode编码转为UTF8
bool UnicodeToUTF8(vector<char>& pu8, const wchar_t* pun, int32 uLen)
{
// convert an widechar string to utf8
int32 utf8Len = WideCharToMultiByte(CP_UTF8, 0, pun, uLen, NULL, 0, NULL, NULL);
if (utf8Len<=0)
{
return false;
}
pu8.resize(utf8Len);
int32 nRtn = WideCharToMultiByte(CP_UTF8, 0, pun, uLen, &*pu8.begin(), utf8Len, NULL, NULL);

if (nRtn != utf8Len)
{
pu8.clear();
return false;
}
return true;
}
[/code]