源：

1. char*->string

(1)直接转换

const char* nodename；string temp = nodename; string temp2(nodename);

2. wchar_t*->wstring

(1)直接转换

const wchar_t* nodename；wstring temp = nodename; wstring temp2(nodename);

3. string->char*

   wstring->char*

方法一：

(1)将wstring.c_str()转为wchar_t*

方法二：

(1)将string.c_str(), wstring.c_str()转为AnsiString（），

(2)将AnsiString.c_str()转为char*

方法一：string temp；const char* nodename = temp.c_str();方法二：struct IPAddress{    std::wstring hostname;    std::vector
     
       ips;};scripting::IPAddress dns = (*pPreloadDns)[i];AnsiString strA = dns.hostname.c_str();char * hn = strA.c_str();
     

但据说这样很不可靠（），安全的做法是：

方法三： String str="123456";int len=str.Length(); char *cp=new char[len+1]; StrPCopy(cp, str);

4. wstring->wchar_t*

    string->w_char*(参见5)

方法一：

(1)将wstring.c_str()转为wchar_t*

方法二.一：

(1)将wstring.c_str()转为UnicodeString 

(2)将UnicodeString.c_str()转为wchar_t*

方法二.二：

(1)将wstring.c_str()转为AnsiString 

(2)使用ANSIToUnicode方法将AnsiString.c_str()转为wchar_t*

方法一：wstring temp;wchar_t* nodename = temp.c_str();方法二.一：struct IPAddress{    std::wstring hostname;    std::vector
     
       ips;};scripting::IPAddress dns = (*pPreloadDns)[i];UnicodeString strA = dns.hostname.c_str();//char * hn = strA.c_str();wchar_t * hn = strA.c_str();方法二.二：struct IPAddress{    std::wstring hostname;    std::vector
      
        ips;};scripting::IPAddress dns = (*pPreloadDns)[i];AnsiString strA = dns.hostname.c_str();//char * hn = strA.c_str();wchar_t * hn = ANSIToUnicode(strA.c_str());
      
     

5. char*->UnicodeString->wstring, wchar_t*

(1)将char*转为UnicodeString

(2)将UnicodeString.c_str()转为wstring, wchar_t*

UnicodeString temp(inet_ntoa(pAddr->sin_addr)) ; //inet_ntoa returns char* std::wstring addr(temp.c_str()); wchar_t* addr2 = temp.c_str(); log_debug(_T("set connection ip:") << addr); con->setIP(addr);

6. wchar_t*->AnsiString->string, char*

(1)将wchar_t*转为AnsiString

(2)将AnsiString.c_str()转为string, char*

wchar_t* str = wstring.c_str(); AnsiString temp(str ) ; //inet_ntoa returns char*

std::string addr(temp.c_str()); char* addr2 = temp.c_str(); log_debug(_T("set connection ip:") << addr); con->setIP(addr);

下面关于string，wstring互转的方法是错误的。对ansi字符可能能得到正确结果，但如果传入的参数是“中文”字符串，将得不到正确的结果。

 7. string->wstring 

static wstring Str2Wstr (string str ){    if (str.length() == 0)        return L"";    std::wstring wstr;    wstr.assign (str.begin(), str.end());    return wstr;}

8. wstring->string

static string Wstr2Str(wstring wstr ){    if (wstr.length() == 0)        return "";    std::string str;    str.assign (wstr.begin(), wstr.end());    return str;}

正确的做法是使用MultiByteToWideChar和WideCharToMultiByte：

9. string->wstring

std::wstring stringToWstring(const std::string& str){    LPCSTR pszSrc = str.c_str();    int nLen = MultiByteToWideChar(CP_ACP, 0, pszSrc, -1, NULL, 0);    if (nLen == 0)         return std::wstring(L"");    wchar_t* pwszDst = new wchar_t[nLen];    if (!pwszDst)         return std::wstring(L"");    MultiByteToWideChar(CP_ACP, 0, pszSrc, -1, pwszDst, nLen);    std::wstring wstr(pwszDst);    delete[] pwszDst;    pwszDst = NULL;    return wstr;}

10. wstring->string

std::string wstringToString(const std::wstring& wstr){    LPCWSTR pwszSrc = wstr.c_str();    int nLen = WideCharToMultiByte(CP_ACP, 0, pwszSrc, -1, NULL, 0, NULL, NULL);    if (nLen == 0)         return std::string("");    char* pszDst = new char[nLen];    if (!pszDst)         return std::string("");    WideCharToMultiByte(CP_ACP, 0, pwszSrc, -1, pszDst, nLen, NULL, NULL);    std::string str(pszDst);    delete[] pszDst;    pszDst = NULL;    return str;}

测试代码：

int _tmain(int argc, _TCHAR* argv[]){    std::string str = "中文";    std::wstring wstr = L"中文";    std::string str1 = "";    std::wstring wstr1 = L"";    LPCSTR pSrc = "中文";    LPCWSTR pwzSrc = L"中文";    stringToWstring(str);    wstringToString(wstr);    stringToWstring(str1);    wstringToString(wstr1);    stringToWstring(pSrc);    wstringToString(pwzSrc);    return 0;}