C++宽字节与多字节之间的转换

参考链接： C++ wmemset()

1.使用WideCharToMultiByte和MultiByteToWideChar； 2.使用mbstowcs_s和wcstombs_s（vs中添加_s）； 3.使用c++11提供的wstring_convert<std::codecvt_utf8<wchar_t>>转换变量 demo：程序如下 下载地址https://pan.baidu.com/s/1yBRYKuRBMLkeMO3v1LJZjg 提取码：oh3t 

#include “iostream” #include “string” #include “locale.h” #include  #include “windows.h” using namespace std; 

//string 与 wstring之间的转换 string ws2s(const wstring &ws) { //setlocale需要头文件#include “locale.h” string curLocale = setlocale(LC_ALL, NULL); setlocale(LC_ALL, “chs”); const wchar_t* _Source = ws.c_str(); size_t _Dsize = 2 * ws.size() + 1; char* _Dest = new char[_Dsize]; memset(_Dest, 0, _Dsize); //wcstombs(_Dest, _Source, _Dsize); 为避免error C4996警告 size_t len = 0; wcstombs_s(&len, _Dest, _Dsize, _Source, _TRUNCATE); string result = _Dest; delete[] _Dest; setlocale(LC_ALL, curLocale.c_str()); return result; } 

wstring s2ws(const string &s) { string curLocale = setlocale(LC_ALL, NULL); setlocale(LC_ALL, “chs”); const char* _Source = s.c_str(); size_t _Dsize = s.size() + 1; wchar_t* _Dest = new wchar_t[_Dsize]; wmemset(_Dest, 0, _Dsize); size_t len = 0; mbstowcs_s(&len, _Dest, _Dsize, _Source, _TRUNCATE); wstring result = _Dest; delete[] _Dest; setlocale(LC_ALL, curLocale.c_str()); return result; } 

//char* 与 wchar_t* 之间的转换 char* wctoc(const wchar_t* str) { if (str == NULL) { return NULL; } DWORD num = WideCharToMultiByte(CP_ACP,0,str,-1,NULL,0,NULL,NULL); char* pRes = new char[num]; WideCharToMultiByte(CP_ACP, 0, str, -1, pRes, num, NULL, NULL); return pRes; } 

wchar_t* ctowc(const char* str) { if (str == NULL) { return NULL; } DWORD num = MultiByteToWideChar(CP_ACP,0,str,-1,NULL,0); wchar_t* pRes = new wchar_t[num]; MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, str, -1, pRes, num); return pRes; } 

int main() { //string wstring 间转换 string s = “12345”; wstring ws = s2ws(s); wchar_t buf[20] = { 0 }; ws.copy(buf, ws.size(), 0); wprintf(L"test s2ws:%ws\n", buf); 

wstring ws2 = L"12345";

string s2 = ws2s(ws2);

char buf2[20] = { 0 };

s2.copy(buf2, s2.size(), 0);

printf("test ws2s:%s\n", buf2);

//char* 与wchar_t* 之间转换

const wchar_t* ws3 = L"abcde";

const char* s3 = wctoc(ws3);

printf("test2 wctoc: %s\n", s3);

delete[] s3;

s3 = NULL;

const char* s4 = "abcde";

const wchar_t* ws4 = ctowc(s4);

wprintf(L"test2 ctowc:%ws", ws4);

delete[] ws4;

ws4 = NULL;

wstring ws5{ L"Hello world." };

string s5;

// 声明一个用于转换的变量cv。所有的转换都经过此变量。

//头文件#include <codecvt>

wstring_convert<std::codecvt_utf8<wchar_t>> cv; 

s5 = cv.to_bytes(ws5);// 宽字节转多字节

printf("test3 ws to s:%s\n", s5.c_str());

string s6("helloworld");

wstring ws6 = cv.from_bytes(s6);// 多字节转宽字节

wprintf(L"test4 s to ws:%ws\n", ws6.c_str());

return 0;

}