c++ 数据类型转换

std::string 转 int

string str;
int istr = std::atoi(str.c_str());

char* 转 int

char* tok;
int itok = atoi(tok);

std::string 或者 const char* 转 char*

string str;
char* cstr = const_cast<char*>(str.c_str());

char* 转 CString

char c[80];
CString str;
str.Format("%s", c); 

char* 转 __int64

const char* htstr;
__int64 ht = _atoi64(htstr);

CString 转 __int64

CString str;
__int64 htFile = _atoi64(str);

CString 转 double

CString str;
double rate = atof(str);

std::string 转 __int64

std::string str;
__int64 htFile = _atoi64(str.c_str());

 std::string 转 BSTR

#include<comutil.h>
#pragma comment(lib, "comsuppw.lib")
std::string str;
BSTR bstr = _com_util::ConvertStringToBSTR(str.c_str());

 std::string 转 std::wstring (utf8编码转unicode编码)

#include <codecvt> 
std::string name;
std::wstring_convert<std::codecvt_utf8<wchar_t>> wcv; 
std::wstring wideStr = wcv.from_bytes(name);

或者

string str="yl";
wstring result;
int len=MultiByteToWideChar(CP_ACP,0,str.c_str(),str.size(),NULL,0);
TCHAR* buffer = new TCHAR[len+1];
MultiByteToWideChar(CP_ACP,0,str.c_str(),str.size(),buffer,len);
buffer[len]='\0';
result.append(buffer);
delete[] buffer;

 C++ wstring和string相互转换的几种方法_Panix2n_n的博客-CSDN博客_c++ wstring转string

 

std::wstring 转 unsigned char (unicode编码转GBK18030/GBK/GB2312)

unicode 码点、 unicode utf8编码、GB2312/GBK/GB18030编码的互转的例子_brooknew的博客-CSDN博客

std::wstring wideStr;
unsigned char bb[256];
WideCharToMultiByte(CP_ACP,0,wideStr.c_str(),-1,(LPSTR)bb,sizeof(bb),NULL,NULL);

std::string 转 sdbyte

std::string 转 std::wstring 转 unsigned char

 数值类型 转 std::string

std::string str = std::to_string(数值变量);

gb2312 转 utf-8 std::string

const char* gbstr

int len = MultiByteToWideChar(CP_ACP,0,gbstr,-1,NULL,0);
wchar_t* wstr = new wchar_t[len+1];
memset(wstr,0,len+1);
MultiByteToWideChar(CP_ACP,0,gbstr,-1,wstr,len);
len = WideCharToMultiByte(CP_UTF8,0,wstr,-1,NULL,0,NULL,NULL);
char* str = new char[len+1];
memset(str,0,len+1);
WideCharToMultiByte(CP_UTF8,0,wstr,-1,str,len,NULL,NULL);
if(wstr)
{
    delete[] wstr;
}