C++ wstring string char* wchar_t相互转换

时间:2021-08-12 21:30:49

标签: stringwstringwchar_tcharc++
2013-12-19 00:29 3721人阅读 评论(0) 收藏 举报
本文章已收录于: C++知识库
分类: C/C++(50)
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(http://blog.csdn.net/bannico/article/details/7577728),

(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<std::wstring> 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(http://bbs.csdn.NET/topics/30479944),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<std::wstring> 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<std::wstring> 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;
}

Original URL: http://www.cnblogs.com/zhcncn/archive/2013/05/20/3089084.html