c++中char*\wchar_t*\string\wstring之间的相互转换 .

#ifndef USE_H_
#define USE_H_
#include <iostream>
#include <windows.h>
#include <string>
using namespace std;
class CUser
{
public:
 CUser();
 virtual~ CUser();
 char* WcharToChar(const wchar_t* wp);
 char* StringToChar(const string& s);
 char* WstringToChar(const wstring& ws);
 wchar_t* CharToWchar(const char* c);
 wchar_t* WstringToWchar(const wstring& ws);
 wchar_t* StringToWchar(const string& s);
 wstring StringToWstring(const string& s);
 string WstringToString(const wstring& ws);
 void Release();
private:
 char* m_char;
 wchar_t* m_wchar;
};
#endif;
 
 
 
#include "stdafx.h"
#include "use.h"
CUser::CUser()
:m_char(NULL)
,m_wchar(NULL)
{
}
CUser::~CUser()
{
 Release();
}
char* CUser::WcharToChar(const wchar_t* wp)
{
 Release();
 int len= WideCharToMultiByte(CP_ACP,0,wp,wcslen(wp),NULL,0,NULL,NULL);
 m_char=new char[len+1];
 WideCharToMultiByte(CP_ACP,0,wp,wcslen(wp),m_char,len,NULL,NULL);
 m_char[len]='\0';
 return m_char;
}
wchar_t* CUser::CharToWchar(const char* c)
{
 Release();
 int len = MultiByteToWideChar(CP_ACP,0,c,strlen(c),NULL,0);
 m_wchar=new wchar_t[len+1];
 MultiByteToWideChar(CP_ACP,0,c,strlen(c),m_wchar,len);
 m_wchar[len]='\0';
 return m_wchar;
}
void CUser::Release()
{
 if(m_char)
 {
  delete m_char;
  m_char=NULL;
 }
 if(m_wchar)
 {
  delete m_wchar;
  m_wchar=NULL;
 }
}
char* CUser::StringToChar(const string& s)
{
 return const_cast<char*>(s.c_str());
}
char* CUser::WstringToChar(const std::wstring &ws)
{
 const wchar_t* wp=ws.c_str();
 return WcharToChar(wp);
}
wchar_t* CUser::WstringToWchar(const std::wstring &ws)
{
 return const_cast<wchar_t*>(ws.c_str());
}
wchar_t* CUser::StringToWchar(const string& s)
{
 const char* p=s.c_str();
 return CharToWchar(p);
}
string CUser::WstringToString(const std::wstring &ws)
{
 string s;
 char* p=WstringToChar(ws);
 s.append(p);
 return s;
}
wstring CUser::StringToWstring(const std::string &s)
{
 wstring ws;
 wchar_t* wp=StringToWchar(s);
 ws.append(wp);
 return ws;
}