string类型转LPCTSTR

今天在写MFC的时候，发现MessageBox函数的类型是LPCTSTR，而我使用C++ STL的string类型却无法直接转，所以在网上找到一段函数，用于转化

std::wstring StoWs(const std::string& s)
{
 int len;
 int slength = (int)s.length() + 1;
 len = MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, 0, 0);
 wchar_t* buf = new wchar_t[len];
 MultiByteToWideChar(CP_ACP, 0, s.c_str(), slength, buf, len);
 std::wstring r(buf);
 delete[] buf;
 return r;
}

std::string s;

如果是 UNICODE 字符的话：
std::wstring stemp = StoWs(s); 

LPCWSTR result = stemp.c_str();

如果不是：
LPCWSTR result = s.c_str();

另附上一段对应类型表

LPSTR - (long) pointer to string - char *

LPCSTR - (long) pointer to constant string - const char *

LPWSTR - (long) pointer to Unicode (wide) string - wchar_t *

LPCWSTR - (long) pointer to constant Unicode (wide) string - const wchar_t *

LPTSTR - (long) pointer to TCHAR (Unicode if UNICODE is defined, ANSI if not) string - TCHAR *

LPCTSTR - (long) pointer to constant TCHAR string - const TCHAR *