string和wstring的互转

参考博客：https://blog.csdn.net/liminwang0311/article/details/79975174

#include <Windows.h>
//将string转换成wstring
wstring string2wstring(string str)
{
    wstring result;
    //获取缓冲区大小，并申请空间，缓冲区大小按字符计算
    int len = MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.size(), NULL, 0);
    TCHAR* buffer = new TCHAR[len + 1];
    //多字节编码转换成宽字节编码
    MultiByteToWideChar(CP_ACP, 0, str.c_str(), str.size(), buffer, len);
    buffer[len] = '\0';             //添加字符串结尾
    //删除缓冲区并返回值
    result.append(buffer);
    delete[] buffer;
    return result;
}

//将wstring转换成string
string wstring2string(wstring wstr)
{
    string result;
    //获取缓冲区大小，并申请空间，缓冲区大小事按字节计算的
    int len = WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), wstr.size(), NULL, 0, NULL, NULL);
    char* buffer = new char[len + 1];
    //宽字节编码转换成多字节编码
    WideCharToMultiByte(CP_ACP, 0, wstr.c_str(), wstr.size(), buffer, len, NULL, NULL);
    buffer[len] = '\0';
    //删除缓冲区并返回值
    result.append(buffer);
    delete[] buffer;
    return result;
}